Measurement of the $W$ Boson Polarization in Top Decay \\ at CDF at $\sqrt{s}$ = 1.8 TeV
D. Acosta $^{14}$
T. Affolder $^{25}$
H. Akimoto $^{50}$
M. G. Albrow $^{13}$
D. Ambrose $^{37}$
D. Amidei $^{28}$
K. Anikeev $^{27}$
J. Antos $^{1}$
G. Apollinari $^{13}$
T. Arisawa $^{50}$
A. Artikov $^{11}$
T. Asakawa $^{48}$
W. Ashmanskas $^{10}$
F. Azfar $^{35}$
P. Azzi-Bacchetta $^{36}$
N. Bacchetta $^{36}$
H. Bachacou $^{25}$
W. Badgett $^{13}$
S. Bailey $^{18}$
P. de Barbaro $^{41}$
A. Barbaro-Galtieri $^{25}$
V. E. Barnes $^{40}$
B. A. Barnett $^{21}$
S. Baroiant $^{5}$
M. Barone $^{15}$
G. Bauer $^{27}$
F. Bedeschi $^{38}$
S. Behari $^{21}$
S. Belforte $^{47}$
W. H. Bell $^{17}$
G. Bellettini $^{38}$
J. Bellinger $^{51}$
D. Benjamin $^{12}$
J. Bensinger $^{4}$
A. Beretvas $^{13}$
J. Berryhill $^{10}$
A. Bhatti $^{42}$
M. Binkley $^{13}$
D. Bisello $^{36}$
M. Bishai $^{13}$
R. E. Blair $^{2}$
C. Blocker $^{4}$
K. Bloom $^{28}$
B. Blumenfeld $^{21}$
S. R. Blusk $^{41}$
A. Bocci $^{42}$
A. Bodek $^{41}$
G. Bolla $^{40}$
A. Bolshov $^{27}$
Y. Bonushkin $^{6}$
D. Bortoletto $^{40}$
J. Boudreau $^{39}$
A. Brandl $^{31}$
C. Bromberg $^{29}$
M. Brozovic $^{12}$
E. Brubaker $^{25}$
N. Bruner $^{31}$
J. Budagov $^{11}$
H. S. Budd $^{41}$
K. Burkett $^{18}$
G. Busetto $^{36}$
K. L. Byrum $^{2}$
S. Cabrera $^{12}$
P. Calafiura $^{25}$
M. Campbell $^{28}$
W. Carithers $^{25}$
J. Carlson $^{28}$
D. Carlsmith $^{51}$
W. Caskey $^{5}$
A. Castro $^{3}$
D. Cauz $^{47}$
A. Cerri $^{38}$
L. Cerrito $^{20}$
A. W. Chan $^{1}$
P. S. Chang $^{1}$
P. T. Chang $^{1}$
J. Chapman $^{28}$
C. Chen $^{37}$
Y. C. Chen $^{1}$
M.-T. Cheng $^{1}$
M. Chertok $^{5}$
G. Chiarelli $^{38}$
I. Chirikov-Zorin $^{11}$
G. Chlachidze $^{11}$
F. Chlebana $^{13}$
L. Christofek $^{20}$
M. L. Chu $^{1}$
J. Y. Chung $^{33}$
W.-H. Chung $^{51}$
Y. S. Chung $^{41}$
C. I. Ciobanu $^{33}$
A. G. Clark $^{16}$
M. Coca $^{38}$
A. P. Colijn $^{13}$
A. Connolly $^{25}$
M. Convery $^{42}$
J. Conway $^{43}$
M. Cordelli $^{15}$
J. Cranshaw $^{45}$
R. Culbertson $^{13}$
D. Dagenhart $^{4}$
S. D'Auria $^{17}$
S. De Cecco $^{43}$
F. DeJongh $^{13}$
S. Dell'Agnello $^{15}$
M. Dell'Orso $^{38}$
S. Demers $^{41}$
L. Demortier $^{42}$
M. Deninno $^{3}$
D. De Pedis $^{43}$
P. F. Derwent $^{13}$
T. Devlin $^{43}$
C. Dionisi $^{43}$
J. R. Dittmann $^{13}$
A. Dominguez $^{25}$
S. Donati $^{38}$
M. D'Onofrio $^{38}$
T. Dorigo $^{36}$
I. Dunietz $^{13}$
N. Eddy $^{20}$
K. Einsweiler $^{25}$
E. Engels Jr. $^{39}$
R. Erbacher $^{13}$
D. Errede $^{20}$
S. Errede $^{20}$
R. Eusebi $^{41}$
Q. Fan $^{41}$
H.-C. Fang $^{25}$
S. Farrington $^{17}$
R. G. Feild $^{52}$
J. P. Fernandez $^{40}$
C. Ferretti $^{38}$
R. D. Field $^{14}$
I. Fiori $^{3}$
B. Flaugher $^{13}$
L. R. Flores-Castillo $^{39}$
G. W. Foster $^{13}$
M. Franklin $^{18}$
J. Freeman $^{13}$
J. Friedman $^{27}$
Y. Fukui $^{23}$
I. Furic $^{27}$
S. Galeotti $^{38}$
A. Gallas $^{32}$
M. Gallinaro $^{42}$
T. Gao $^{37}$
M. Garcia-Sciveres $^{25}$
A. F. Garfinkel $^{40}$
P. Gatti $^{36}$
C. Gay $^{52}$
D. W. Gerdes $^{28}$
E. Gerstein $^{9}$
S. Giagu $^{43}$
P. Giannetti $^{38}$
K. Giolo $^{40}$
M. Giordani $^{5}$
P. Giromini $^{15}$
V. Glagolev $^{11}$
D. Glenzinski $^{13}$
M. Gold $^{31}$
J. Goldstein $^{13}$
G. Gomez $^{8}$
M. Goncharov $^{44}$
I. Gorelov $^{31}$
A. T. Goshaw $^{12}$
Y. Gotra $^{39}$
K. Goulianos $^{42}$
C. Green $^{40}$
A. Gresele $^{36}$
G. Grim $^{5}$
C. Grosso-Pilcher $^{10}$
M. Gu enther $^{40}$
G. Guillian $^{28}$
J. Guimaraes da Costa $^{18}$
R. M. Haas $^{14}$
C. Haber $^{25}$
S. R. Hahn $^{13}$
E. Halkiadakis $^{41}$
C. Hall $^{18}$
T. Handa $^{19}$
R. Ha ndler $^{51}$
F. Happacher $^{15}$
K. Hara $^{48}$
A. D. Hardman $^{40}$
R. M. Harris $^{13}$
F. Hartmann $^{22}$
K. Hatakeyama $^{42}$
J. Hauser $^{6}$
J. Heinrich $^{37}$
A. Heiss $^{22}$
M. Hennecke $^{22}$
M. Herndon $^{21}$
C. Hill $^{7}$
A. Hocker $^{41}$
K. D. Hoffman $^{10}$
R. Hollebeek $^{37}$
L. Holloway $^{20}$
S. Hou $^{1}$
B. T. Huffman $^{35}$
R. Hughes $^{33}$
J. Huston $^{29}$
J. Huth $^{18}$
H. Ikeda $^{48}$
J. Incandela $^{7}$
G. Introzzi $^{38}$
M. Iori $^{43}$
A. Ivanov $^{41}$
J. Iwai $^{50}$
Y. Iwata $^{19}$
B. Iyutin $^{27}$
E. James $^{28}$
M. Jones $^{37}$
U. Joshi $^{13}$
H. Kambara $^{16}$
T. Kamon $^{44}$
T. Kaneko $^{48}$
M. Karagoz Unel $^{32}$
K. Karr $^{49}$
S. Kartal $^{13}$
H. Kasha $^{52}$
Y. Kato $^{34}$
T. A. Keaffaber $^{40}$
K. Kelley $^{27}$
M. Kelly $^{28}$
R. D. Kennedy $^{13}$
R. Kephart $^{13}$
D. Khazins $^{12}$
T. Kikuchi $^{48}$
B. Kilminster $^{41}$
B. J. Kim $^{24}$
D. H. Kim $^{24}$
H. S. Kim $^{20}$
M. J. Kim $^{9}$
S. B. Kim $^{24}$
S. H. Kim $^{48}$
T. H. Kim $^{27}$
Y. K. Kim $^{25}$
M. Kirby $^{12}$
M. Kirk $^{4}$
L. Kirsch $^{4}$
S. Klimenko $^{14}$
P. Koehn $^{33}$
K. Kondo $^{50}$
J. Konigsberg $^{14}$
A. Korn $^{27}$
A. Korytov $^{14}$
K. Kotelnikov $^{30}$
E. Kovacs $^{2}$
J. Kroll $^{37}$
M. Kruse $^{12}$
V. Krutelyov $^{44}$
S. E. Kuhlmann $^{2}$
K. Kurino $^{19}$
T. Kuwabara $^{48}$
A. T. Laasanen $^{40}$
N. Lai $^{10}$
S. Lami $^{42}$
S. Lammel $^{13}$
J. Lancaster $^{12}$
K. Lannon $^{20}$
M. Lancaster $^{26}$
R. Lander $^{5}$
A. Lath $^{43}$
G. Latino $^{31}$
T. LeCompte $^{2}$
Y. Le $^{21}$
S. W. Lee $^{44}$
N. Leonardo $^{27}$
S. Leone $^{38}$
J. D. Lewis $^{13}$
K. Li $^{53}$
M. Lindgren $^{6}$
T. M. Liss $^{20}$
J. B. Liu $^{41}$
T. Liu $^{13}$
Y. C. Liu $^{1}$
D. O. Litvintsev $^{13}$
O. Lobban $^{45}$
N. S. Lockyer $^{37}$
A. Loginov $^{30}$
J. Loken $^{35}$
M. Loreti $^{36}$
D. L ucchesi $^{36}$
P. Lukens $^{13}$
S. Lusin $^{51}$
L. Lyons $^{35}$
J. Lys $^{25}$
R. Madrak $^{18}$
K. Maeshima $^{13}$
P. Maksimovic $^{21}$
L. Malferrari $^{3}$
M. Mangano $^{38}$
G. Manca $^{35}$
M. Mariotti $^{36}$
G. Martignon $^{36}$
M. Martin $^{21}$
A. Martin $^{52}$
V. Martin $^{32}$
J. A. J. Matthews $^{31}$
P. Mazzanti $^{3}$
K. S. McFarland $^{41}$
P. McIntyre $^{44}$
M. Menguzzato $^{36}$
A. Menzione $^{38}$
P. Merkel $^{13}$
C. Mesropian $^{42}$
A. Meyer $^{13}$
T. Miao $^{13}$
R. Miller $^{29}$
J. S. Miller $^{28}$
H. Minato $^{48}$
S. Miscetti $^{15}$
M. Mishina $^{23}$
G. Mitselmakher $^{14}$
Y. Miyazaki $^{34}$
N. Moggi $^{3}$
E. Moore $^{31}$
R. Moore $^{28}$
Y. Morita $^{23}$
T. Moulik $^{40}$
M. Mulhearn $^{27}$
A. Mukherjee $^{13}$
T. Muller $^{22}$
A. Munar $^{38}$
P. Murat $^{13}$
S. Murgia $^{29}$
J. Nachtman $^{6}$
V. Nagaslaev $^{45}$
S. Nahn $^{52}$
H. Nakada $^{48}$
I. Nakano $^{19}$
R. Napora $^{21}$
C. Nelson $^{13}$
T. Nelson $^{13}$
C. Neu $^{33}$
M. S. Neubauer $^{27}$
D. Neuberger $^{22}$
C. Newman-Holmes $^{13}$
C.-Y. P. Ngan $^{27}$
T. Nigmanov $^{39}$
H. Niu $^{4}$
L. Nodulman $^{2}$
A. Nomerotski $^{14}$
S. H. Oh $^{12}$
Y. D. Oh $^{24}$
T. Ohmoto $^{19}$
T. Ohsugi $^{19}$
R. Oishi $^{48}$
T. Okusawa $^{34}$
J. Olsen $^{51}$
W. Orejudos $^{25}$
C. Pagliarone $^{38}$
F. Palmonari $^{38}$
R. Paoletti $^{38}$
V. Papadimitriou $^{45}$
D. Partos $^{4}$
J. Patrick $^{13}$
G. Pauletta $^{47}$
M. Paulini $^{9}$
T. Pauly $^{35}$
C. Paus $^{27}$
D. Pellett $^{5}$
A. Penzo $^{47}$
L. Pescara $^{36}$
T. J. Phillips $^{12}$
G. Pi acentino $^{38}$
J. Piedra $^{8}$
K. T. Pitts $^{20}$
A. Pompos $^{40}$
L. Pondrom $^{51}$
G. Pope $^{39}$
T. Pratt $^{35}$
F. Prokoshin $^{11}$
J. Proudfoot $^{2}$
F. Ptohos $^{15}$
O. Pukhov $^{11}$
G. Punzi $^{38}$
J. Rademacker $^{35}$
A. Rakitine $^{27}$
F. Ratnikov $^{43}$
D. Reher $^{25}$
A. Reichold $^{35}$
P. Renton $^{35}$
M. Rescigno $^{43}$
A. Ribon $^{36}$
W. Riegler $^{18}$
F. Rimondi $^{3}$
L. Ristori $^{38}$
M. Riveline $^{46}$
W. J. Robertson $^{12}$
T. Rodrigo $^{8}$
S. Rolli $^{49}$
L. Rosenson $^{27}$
R. Roser $^{13}$
R. Rossin $^{36}$
C. Rott $^{40}$
A. Roy $^{40}$
A. Ruiz $^{8}$
D. Ryan $^{49}$
A. Safonov $^{5}$
R. St. Denis $^{17}$
W. K. Sakumoto $^{41}$
D. Saltzberg $^{6}$
C. Sanchez $^{33}$
A. Sansoni $^{15}$
L. Santi $^{47}$
S. Sarkar $^{43}$
H. Sato $^{48}$
P. Savard $^{46}$
A. Savoy-Navarro $^{13}$
P. Schlabach $^{13}$
E. E. Schmidt $^{13}$
M. P. Schmidt $^{52}$
M. Schmitt $^{32}$
L. Scodellaro $^{36}$
A. Scott $^{6}$
A. Scribano $^{38}$
A. Sedov $^{40}$
S. Seidel $^{31}$
Y. Seiya $^{48}$
A. Semenov $^{11}$
F. Semeria $^{3}$
T. Shah $^{27}$
M. D. Shapiro $^{25}$
P. F. Shepard $^{39}$
T. Shibayama $^{48}$
M. Shimojima $^{48}$
M. Shochet $^{10}$
A. Sidoti $^{36}$
J. Siegrist $^{25}$
A. Sill $^{45}$
P. Sinervo $^{46}$
P. Singh $^{20}$
A. J. Slaughter $^{52}$
K. Sliwa $^{49}$
F. D. Snider $^{13}$
R. Snihur $^{26}$
A. Solodsky $^{42}$
J. Spalding $^{13}$
T . Speer $^{16}$
M. Spezziga $^{45}$
P. Sphicas $^{27}$
F. Spinella $^{38}$
M. Spiropulu $^{10}$
L. Spiegel $^{13}$
J. Steele $^{51}$
A. Stefanini $^{38}$
J. Strologas $^{20}$
F. Strumia $^{16}$
D. Stuart $^{7}$
A. Sukhanov $^{14}$
K. Sumorok $^{27}$
T. Suzuki $^{48}$
T. Takano $^{35}$
R. Takashima $^{19}$
K. Takikawa $^{48}$
P. Tamburello $^{12}$
M. Tanaka $^{48}$
B. Tannenbaum $^{6}$
M. Tecchio $^{28}$
R. J. Tesarek $^{13}$
P. K. Teng $^{1}$
K. Terashi $^{42}$
S. Tether $^{27}$
A. S. Thompson $^{17}$
E. Thomson $^{33}$
R. Thurman-Keup $^{2}$
P. Tipton $^{41}$
S. Tkaczyk $^{13}$
D. Toback $^{44}$
K. Tollefson $^{29}$
A. Tollestrup $^{13}$
D. Tonelli $^{38}$
M. Tonnesmann $^{29}$
H. Toyoda $^{34}$
W. Trischuk $^{46}$
J. F. de Troconiz $^{18}$
J. Tseng $^{27}$
D. Tsybychev $^{14}$
N. Turini $^{38}$
F. Ukegawa $^{48}$
T. Unverhau $^{17}$
T. Vaiciulis $^{41}$
J. Valls $^{43}$
E. Vataga $^{38}$
S. Vejcik III $^{13}$
G. Velev $^{13}$
G. Veramendi $^{25}$
R. Vidal $^{13}$
I. Vila $^{8}$
R. Vilar $^{8}$
I. Volobouev $^{25}$
M. von der Mey $^{6}$
D. Vucinic $^{27}$
R. G. Wagner $^{2}$
R. L. Wagner $^{13}$
W. Wagner $^{22}$
N. B. Wallace $^{43}$
Z. Wan $^{43}$
C. Wang $^{12}$
M. J. Wang $^{1}$
S. M. Wang $^{14}$
B. Ward $^{17}$
S. Waschke $^{17}$
T. Watanabe $^{48}$
D. Waters $^{26}$
T. Watts $^{43}$
M. Weber $^{25}$
H. Wenzel $^{22}$
W. C. Wester III $^{13}$
B. Whitehouse $^{49}$
A. B. Wicklund $^{2}$
E. Wicklund $^{13}$
T. Wilkes $^{5}$
H. H. Williams $^{37}$
P. Wilson $^{13}$
B. L. Winer $^{33}$
D. Winn $^{28}$
S. Wolbers $^{13}$
D. Wolinski $^{28}$
J. Wolinski $^{29}$
S. Wolinski $^{28}$
M. Wolter $^{49}$
S. Worm $^{43}$
X. Wu $^{16}$
F. W\"urthwein $^{27}$
J. Wyss $^{38}$
U. K. Yang $^{10}$
W. Yao $^{25}$
G. P. Yeh $^{13}$
P. Yeh $^{1}$
K. Yi $^{21}$
J. Yoh $^{13}$
C. Yosef $^{29}$
T. Yoshida $^{34}$
I. Yu $^{24}$
S. Yu $^{37}$
Z. Yu $^{52}$
J. C. Yun $^{13}$
L. Zanello $^{43}$
A. Zanetti $^{47}$
F. Zetti $^{25}$
and S. Zucchelli $^{3}$
The polarization of the $W$ boson in $t \to W b$ decay is unambiguously predicted by the Standard Model of electroweak interactions and is a powerful test of our understanding of the $tbW$ vertex. We measure this polarization from the invariant mass of the $b$ quark from $t \to W b$ and the lepton from $W \to l \nu$ whose momenta measure the $W$ decay angle and direction of motion, respectively. In this paper we present a measurement of the decay rate ($f_{V+A}$) of the $W$ produced from the decay of the top quark in the hypothesis of V$+$A structure of the $tWb$ vertex. We find no evidence for the non-standard V$+$A vertex and set a limit on $f_{V+A}$ $<$ 0.80 at 95\% confidence level. By combining this result with a complementary observable in the same data, we assign a limit on $f_{V+A}$ $<$ 0.61 at 95\% CL. This corresponds to a constraint on the right-handed helicity component of the W polarization of $f_{+} < 0.18$ at 95\% CL. This limit is the first significant direct constraint on $f_{V+A}$ in top decay.
abstract.tex
%auto-ignore
\begin{abstract}
The polarization of the $W$ boson in $t \to W b$ decay is unambiguously
predicted by the Standard Model of electroweak interactions and is a powerful
test of our understanding of the $tbW$ vertex.  We measure this polarization
from the invariant mass of the $b$ quark from $t \to W b$ and the lepton from
$W \to l \nu$ whose momenta measure the $W$ decay angle and direction of
motion, respectively.  In this paper we present a measurement of the decay
rate ($f_{V+A}$) of the $W$ produced from the decay of the top quark in the
hypothesis of V$+$A structure of the $tWb$ vertex.  We find no evidence for
the non-standard V$+$A vertex and set a limit on $f_{V+A}$ $<$ 0.80 at 95\%
confidence level. By combining this result with a complementary observable in
the same data, we assign a limit on $f_{V+A}$ $<$ 0.61 at 95\% CL.  This
corresponds to a constraint on the right-handed helicity component of the W
polarization of $f_{+} < 0.18$ at 95\% CL.  This limit is the first
significant direct constraint on $f_{V+A}$ in top decay.
\end{abstract}


ack.tex

We thank the Fermilab staff and the technical staffs of the participating
institutions for their vital contributions.  This work was supported by the
U.S. Department of Energy and National Science Foundation; the Italian
Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture,
Sports, Science and Technology of Japan; the Natural Sciences and Engineering
Research Council of Canada; the National Science Council of the Republic of
China; the Swiss National Science Foundation; the A.P. Sloan Foundation; the
Research Corporation; the Bundesministerium fuer Bildung und Forschung,
Germany; the Korean Science and Engineering Foundation and the Korean
Research Foundation; the Particle Physics and Astronomy Research Council and
the Royal Society, UK; the Russian Foundation for Basic Research; the
Comision Interministerial de Ciencia y Tecnologia, Spain; work supported in
part by the European Community's Human Potential Programme under contract
HPRN-CT-20002, Probe for New Physics; and this work was supported by Research
Fund of Istanbul University Project No. 1755/21122001.

author.tex
%auto-ignore
\author{
D. Acosta $^{14}$, T. Affolder $^{25}$, H. Akimoto $^{50}$,
M. G. Albrow $^{13}$, D. Ambrose $^{37}$, D. Amidei $^{28}$, K. Anikeev
$^{27}$, J. Antos $^{1}$, G. Apollinari $^{13}$, T. Arisawa $^{50}$,
A. Artikov $^{11}$, T. Asakawa $^{48}$, W. Ashmanskas $^{10}$, F. Azfar
$^{35}$, P. Azzi-Bacchetta $^{36}$, N. Bacchetta $^{36}$, H. Bachacou
$^{25}$, W. Badgett $^{13}$, S. Bailey $^{18}$, P. de Barbaro $^{41}$,
A. Barbaro-Galtieri $^{25}$, V. E. Barnes $^{40}$, B. A. Barnett $^{21}$,
S. Baroiant $^{5}$, M. Barone $^{15}$, G. Bauer $^{27}$, F. Bedeschi $^{38}$,
S. Behari $^{21}$, S. Belforte $^{47}$, W. H. Bell $^{17}$, G. Bellettini
$^{38}$, J. Bellinger $^{51}$, D. Benjamin $^{12}$, J. Bensinger $^{4}$,
A. Beretvas $^{13}$, J. Berryhill $^{10}$, A. Bhatti $^{42}$, M. Binkley
$^{13}$, D. Bisello $^{36}$, M. Bishai $^{13}$, R. E. Blair $^{2}$,
C. Blocker $^{4}$, K. Bloom $^{28}$, B. Blumenfeld $^{21}$, S. R. Blusk
$^{41}$, A. Bocci $^{42}$, A. Bodek $^{41}$, G. Bolla $^{40}$, A. Bolshov
$^{27}$, Y. Bonushkin $^{6}$, D. Bortoletto $^{40}$, J. Boudreau $^{39}$,
A. Brandl $^{31}$, C. Bromberg $^{29}$, M. Brozovic $^{12}$, E. Brubaker
$^{25}$, N. Bruner $^{31}$, J. Budagov $^{11}$, H. S. Budd $^{41}$,
K. Burkett $^{18}$, G. Busetto $^{36}$, K. L. Byrum $^{2}$, S. Cabrera
$^{12}$, P. Calafiura $^{25}$, M. Campbell $^{28}$, W. Carithers $^{25}$,
J. Carlson $^{28}$, D. Carlsmith $^{51}$, W. Caskey $^{5}$, A. Castro $^{3}$,
D. Cauz $^{47}$, A. Cerri $^{38}$, L. Cerrito $^{20}$, A. W. Chan $^{1}$,
P. S. Chang $^{1}$, P. T. Chang $^{1}$, J. Chapman $^{28}$, C. Chen $^{37}$,
Y. C. Chen $^{1}$, M.-T. Cheng $^{1}$, M. Chertok $^{5}$, G. Chiarelli
$^{38}$, I. Chirikov-Zorin $^{11}$, G. Chlachidze $^{11}$, F. Chlebana
$^{13}$, L. Christofek $^{20}$, M. L. Chu $^{1}$, J. Y. Chung $^{33}$,
W.-H. Chung $^{51}$, Y. S. Chung $^{41}$, C. I. Ciobanu $^{33}$, A. G. Clark
$^{16}$, M. Coca $^{38}$, A. P. Colijn $^{13}$, A. Connolly $^{25}$,
M. Convery $^{42}$, J. Conway $^{43}$, M. Cordelli $^{15}$, J. Cranshaw
$^{45}$, R. Culbertson $^{13}$, D. Dagenhart $^{4}$, S. D'Auria $^{17}$,
S. De Cecco $^{43}$, F. DeJongh $^{13}$, S. Dell'Agnello $^{15}$,
M. Dell'Orso $^{38}$, S. Demers $^{41}$, L. Demortier $^{42}$, M. Deninno
$^{3}$, D. De Pedis $^{43}$, P. F. Derwent $^{13}$, T. Devlin $^{43}$,
C. Dionisi $^{43}$, J. R. Dittmann $^{13}$, A. Dominguez $^{25}$, S. Donati
$^{38}$, M. D'Onofrio $^{38}$, T. Dorigo $^{36}$, I. Dunietz $^{13}$, N. Eddy
$^{20}$, K. Einsweiler $^{25}$, E. Engels Jr. $^{39}$, R. Erbacher
$^{13}$, D. Errede $^{20}$, S. Errede $^{20}$, R. Eusebi $^{41}$, Q. Fan
$^{41}$, H.-C. Fang $^{25}$, S. Farrington $^{17}$, R. G. Feild $^{52}$,
J. P. Fernandez $^{40}$, C. Ferretti $^{38}$, R. D. Field $^{14}$, I. Fiori
$^{3}$, B. Flaugher $^{13}$, L. R. Flores-Castillo $^{39}$, G. W. Foster
$^{13}$, M. Franklin $^{18}$, J. Freeman $^{13}$, J. Friedman $^{27}$,
Y. Fukui $^{23}$, I. Furic $^{27}$, S. Galeotti $^{38}$, A. Gallas $^{32}$,
M. Gallinaro $^{42}$, T. Gao $^{37}$, M. Garcia-Sciveres $^{25}$,
A. F. Garfinkel $^{40}$, P. Gatti $^{36}$, C. Gay $^{52}$, D. W. Gerdes
$^{28}$, E. Gerstein $^{9}$, S. Giagu $^{43}$, P. Giannetti $^{38}$, K. Giolo
$^{40}$, M. Giordani $^{5}$, P. Giromini $^{15}$, V. Glagolev $^{11}$,
D. Glenzinski $^{13}$, M. Gold $^{31}$, J. Goldstein $^{13}$, G. Gomez
$^{8}$, M. Goncharov $^{44}$, I. Gorelov $^{31}$, A. T. Goshaw $^{12}$,
Y. Gotra $^{39}$, K. Goulianos $^{42}$, C. Green $^{40}$, A. Gresele $^{36}$,
G. Grim $^{5}$, C. Grosso-Pilcher $^{10}$, M. Gu enther $^{40}$, G. Guillian
$^{28}$, J. Guimaraes da Costa $^{18}$, R. M. Haas $^{14}$, C. Haber $^{25}$,
S. R. Hahn $^{13}$, E. Halkiadakis $^{41}$, C. Hall $^{18}$, T. Handa
$^{19}$, R. Ha ndler $^{51}$, F. Happacher $^{15}$, K. Hara $^{48}$,
A. D. Hardman $^{40}$, R. M. Harris $^{13}$, F. Hartmann $^{22}$,
K. Hatakeyama $^{42}$, J. Hauser $^{6}$, J. Heinrich $^{37}$, A. Heiss
$^{22}$, M. Hennecke $^{22}$, M. Herndon $^{21}$, C. Hill $^{7}$, A. Hocker
$^{41}$, K. D. Hoffman $^{10}$, R. Hollebeek $^{37}$, L. Holloway $^{20}$,
S. Hou $^{1}$, B. T. Huffman $^{35}$, R. Hughes $^{33}$, J. Huston $^{29}$,
J. Huth $^{18}$, H. Ikeda $^{48}$, J. Incandela $^{7}$, G. Introzzi $^{38}$,
M. Iori $^{43}$,A. Ivanov $^{41}$, J. Iwai $^{50}$, Y. Iwata $^{19}$,
B. Iyutin $^{27}$, E. James $^{28}$, M. Jones $^{37}$, U. Joshi $^{13}$,
H. Kambara $^{16}$, T. Kamon $^{44}$, T. Kaneko $^{48}$, M. Karagoz Unel
$^{32}$, K. Karr $^{49}$, S. Kartal $^{13}$, H. Kasha $^{52}$, Y. Kato
$^{34}$, T. A. Keaffaber $^{40}$, K. Kelley $^{27}$, M. Kelly $^{28}$,
R. D. Kennedy $^{13}$, R. Kephart $^{13}$, D. Khazins $^{12}$, T. Kikuchi
$^{48}$, B. Kilminster $^{41}$, B. J. Kim $^{24}$, D. H. Kim $^{24}$,
H. S. Kim $^{20}$, M. J. Kim $^{9}$, S. B. Kim $^{24}$, S. H. Kim $^{48}$,
T. H. Kim $^{27}$, Y. K. Kim $^{25}$, M. Kirby $^{12}$, M. Kirk $^{4}$,
L. Kirsch $^{4}$, S. Klimenko $^{14}$, P. Koehn $^{33}$, K. Kondo $^{50}$,
J. Konigsberg $^{14}$, A. Korn $^{27}$, A. Korytov $^{14}$, K. Kotelnikov
$^{30}$, E. Kovacs $^{2}$, J. Kroll $^{37}$, M. Kruse $^{12}$, V. Krutelyov
$^{44}$, S. E. Kuhlmann $^{2}$, K. Kurino $^{19}$, T. Kuwabara $^{48}$,
A. T. Laasanen $^{40}$, N. Lai $^{10}$, S. Lami $^{42}$, S. Lammel $^{13}$,
J. Lancaster $^{12}$, K. Lannon $^{20}$, M. Lancaster $^{26}$, R. Lander
$^{5}$, A. Lath $^{43}$, G. Latino $^{31}$, T. LeCompte $^{2}$, Y. Le
$^{21}$, S. W. Lee $^{44}$, N. Leonardo $^{27}$, S. Leone $^{38}$,
J. D. Lewis $^{13}$, K. Li $^{53}$, M. Lindgren $^{6}$, T. M. Liss $^{20}$,
J. B. Liu $^{41}$, T. Liu $^{13}$, Y. C. Liu $^{1}$, D. O. Litvintsev
$^{13}$, O. Lobban $^{45}$, N. S. Lockyer $^{37}$, A. Loginov $^{30}$,
J. Loken $^{35}$, M. Loreti $^{36}$, D. L ucchesi $^{36}$, P. Lukens $^{13}$,
S. Lusin $^{51}$, L. Lyons $^{35}$, J. Lys $^{25}$, R. Madrak $^{18}$,
K. Maeshima $^{13}$, P. Maksimovic $^{21}$, L. Malferrari $^{3}$, M. Mangano
$^{38}$, G. Manca $^{35}$, M. Mariotti $^{36}$, G. Martignon $^{36}$,
M. Martin $^{21}$, A. Martin $^{52}$, V. Martin $^{32}$, J. A. J. Matthews
$^{31}$, P. Mazzanti $^{3}$, K. S. McFarland $^{41}$, P. McIntyre $^{44}$,
M. Menguzzato $^{36}$, A. Menzione $^{38}$, P. Merkel $^{13}$, C. Mesropian
$^{42}$, A. Meyer $^{13}$, T. Miao $^{13}$, R. Miller $^{29}$, J. S. Miller
$^{28}$, H. Minato $^{48}$, S. Miscetti $^{15}$, M. Mishina $^{23}$,
G. Mitselmakher $^{14}$, Y. Miyazaki $^{34}$, N. Moggi $^{3}$, E. Moore
$^{31}$, R. Moore $^{28}$, Y. Morita $^{23}$, T. Moulik $^{40}$, M. Mulhearn
$^{27}$, A. Mukherjee $^{13}$, T. Muller $^{22}$, A. Munar $^{38}$, P. Murat
$^{13}$, S. Murgia $^{29}$, J. Nachtman $^{6}$, V. Nagaslaev $^{45}$, S. Nahn
$^{52}$, H. Nakada $^{48}$, I. Nakano $^{19}$, R. Napora $^{21}$, C. Nelson
$^{13}$, T. Nelson $^{13}$, C. Neu $^{33}$, M. S. Neubauer $^{27}$,
D. Neuberger $^{22}$, C. Newman-Holmes $^{13}$, C.-Y. P. Ngan $^{27}$,
T. Nigmanov $^{39}$, H. Niu $^{4}$, L. Nodulman $^{2}$, A. Nomerotski
$^{14}$, S. H. Oh $^{12}$, Y. D. Oh $^{24}$, T. Ohmoto $^{19}$, T. Ohsugi
$^{19}$, R. Oishi $^{48}$, T. Okusawa $^{34}$, J. Olsen $^{51}$, W. Orejudos
$^{25}$, C. Pagliarone $^{38}$, F. Palmonari $^{38}$, R. Paoletti $^{38}$,
V. Papadimitriou $^{45}$, D. Partos $^{4}$, J. Patrick $^{13}$, G. Pauletta
$^{47}$, M. Paulini $^{9}$, T. Pauly $^{35}$, C. Paus $^{27}$, D. Pellett
$^{5}$, A. Penzo $^{47}$, L. Pescara $^{36}$, T. J. Phillips $^{12}$, G. Pi
acentino $^{38}$, J. Piedra $^{8}$, K. T. Pitts $^{20}$, A. Pompos $^{40}$,
L. Pondrom $^{51}$, G. Pope $^{39}$, T. Pratt $^{35}$, F. Prokoshin $^{11}$,
J. Proudfoot $^{2}$, F. Ptohos $^{15}$, O. Pukhov $^{11}$, G. Punzi $^{38}$,
J. Rademacker $^{35}$, A. Rakitine $^{27}$, F. Ratnikov $^{43}$, D. Reher
$^{25}$, A. Reichold $^{35}$, P. Renton $^{35}$, M. Rescigno $^{43}$,
A. Ribon $^{36}$, W. Riegler $^{18}$, F. Rimondi $^{3}$, L. Ristori $^{38}$,
M. Riveline $^{46}$, W. J. Robertson $^{12}$, T. Rodrigo $^{8}$, S. Rolli
$^{49}$, L. Rosenson $^{27}$, R. Roser $^{13}$, R. Rossin $^{36}$, C. Rott
$^{40}$, A. Roy $^{40}$, A. Ruiz $^{8}$, D. Ryan $^{49}$, A. Safonov $^{5}$,
R. St. Denis $^{17}$, W. K. Sakumoto $^{41}$, D. Saltzberg $^{6}$, C. Sanchez
$^{33}$, A. Sansoni $^{15}$, L. Santi $^{47}$, S. Sarkar $^{43}$, H. Sato
$^{48}$, P. Savard $^{46}$, A. Savoy-Navarro $^{13}$, P. Schlabach $^{13}$,
E. E. Schmidt $^{13}$, M. P. Schmidt $^{52}$, M. Schmitt $^{32}$,
L. Scodellaro $^{36}$, A. Scott $^{6}$, A. Scribano $^{38}$, A. Sedov
$^{40}$, S. Seidel $^{31}$, Y. Seiya $^{48}$, A. Semenov $^{11}$, F. Semeria
$^{3}$, T. Shah $^{27}$, M. D. Shapiro $^{25}$, P. F. Shepard $^{39}$,
T. Shibayama $^{48}$, M. Shimojima $^{48}$, M. Shochet $^{10}$, A. Sidoti
$^{36}$, J. Siegrist $^{25}$, A. Sill $^{45}$, P. Sinervo $^{46}$, P. Singh
$^{20}$, A. J. Slaughter $^{52}$, K. Sliwa $^{49}$, F. D. Snider $^{13}$,
R. Snihur $^{26}$, A. Solodsky $^{42}$, J. Spalding $^{13}$, T . Speer
$^{16}$, M. Spezziga $^{45}$, P. Sphicas $^{27}$, F. Spinella $^{38}$,
M. Spiropulu $^{10}$, L. Spiegel $^{13}$, J. Steele $^{51}$, A. Stefanini
$^{38}$, J. Strologas $^{20}$, F. Strumia $^{16}$, D. Stuart $^{7}$,
A. Sukhanov $^{14}$, K. Sumorok $^{27}$, T. Suzuki $^{48}$, T. Takano
$^{35}$, R. Takashima $^{19}$, K. Takikawa $^{48}$, P. Tamburello $^{12}$,
M. Tanaka $^{48}$, B. Tannenbaum $^{6}$, M. Tecchio $^{28}$, R. J. Tesarek
$^{13}$, P. K. Teng $^{1}$, K. Terashi $^{42}$, S. Tether $^{27}$,
A. S. Thompson $^{17}$, E. Thomson $^{33}$, R. Thurman-Keup $^{2}$, P. Tipton
$^{41}$, S. Tkaczyk $^{13}$, D. Toback $^{44}$, K. Tollefson $^{29}$,
A. Tollestrup $^{13}$, D. Tonelli $^{38}$, M. Tonnesmann $^{29}$, H. Toyoda
$^{34}$, W. Trischuk $^{46}$, J. F. de Troconiz $^{18}$, J. Tseng $^{27}$,
D. Tsybychev $^{14}$, N. Turini $^{38}$, F. Ukegawa $^{48}$, T. Unverhau
$^{17}$, T. Vaiciulis $^{41}$, J. Valls $^{43}$, E. Vataga $^{38}$, S. Vejcik
III $^{13}$, G. Velev $^{13}$, G. Veramendi $^{25}$, R. Vidal $^{13}$,
I. Vila $^{8}$, R. Vilar $^{8}$, I. Volobouev $^{25}$, M. von der Mey $^{6}$,
D. Vucinic $^{27}$, R. G. Wagner $^{2}$, R. L. Wagner $^{13}$, W. Wagner
$^{22}$, N. B. Wallace $^{43}$, Z. Wan $^{43}$, C. Wang $^{12}$, M. J. Wang
$^{1}$, S. M. Wang $^{14}$, B. Ward $^{17}$, S. Waschke $^{17}$, T. Watanabe
$^{48}$, D. Waters $^{26}$, T. Watts $^{43}$, M. Weber $^{25}$, H. Wenzel
$^{22}$, W. C. Wester III $^{13}$, B. Whitehouse $^{49}$, A. B. Wicklund
$^{2}$, E. Wicklund $^{13}$, T. Wilkes $^{5}$, H. H. Williams $^{37}$,
P. Wilson $^{13}$, B. L. Winer $^{33}$, D. Winn $^{28}$, S. Wolbers $^{13}$,
D. Wolinski $^{28}$, J. Wolinski $^{29}$, S. Wolinski $^{28}$, M. Wolter
$^{49}$, S. Worm $^{43}$, X. Wu $^{16}$, F. W\"urthwein $^{27}$, J. Wyss
$^{38}$, U. K. Yang $^{10}$, W. Yao $^{25}$, G. P. Yeh $^{13}$, P. Yeh
$^{1}$, K. Yi $^{21}$, J. Yoh $^{13}$, C. Yosef $^{29}$, T. Yoshida $^{34}$,
I. Yu $^{24}$, S. Yu $^{37}$, Z. Yu $^{52}$, J. C. Yun $^{13}$, L. Zanello
$^{43}$, A. Zanetti $^{47}$, F. Zetti $^{25}$, and S. Zucchelli $^{3}$
}

\affiliation{
   {\eightit Institute of Physics, Academia Sinica, Taipei, Taiwan 11529, Republic
of China } \\
   $^{2}$ {\eightit Argonne National Laboratory, Argonne, Illinois 60439  } \\
   $^{3}$ {\eightit Istituto Nazionale di Fisica Nucleare, University of Bologna, I-40127
Bologna, Italy } \\
   $^{4}$ {\eightit Brandeis University, Waltham, Massachusetts 02254 } \\
   $^{5}$ {\eightit University of California at Davis, Davis, California 95616 } \\
   $^{6}$ {\eightit University of California at Los Angeles, Los Angeles, California 90024 } \\ 
   $^{7}$ {\eightit University of California at Santa Barbara, Santa Barbara, California 93106  } \\
   $^{8}$ {\eightit Instituto de Fisica de Cantabria, CSIC-University of Cantabria,
39005 Santander, Spain  } \\
   $^{9}$ {\eightit Carnegie Mellon University, Pittsburgh, PA 15218  } \\
  $^{10}$ {\eightit Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637  } \\
  $^{11}$ {\eightit Joint Institute for Nuclear Research, RU-141980 Dubna, Russia  } \\
  $^{12}$ {\eightit Duke University, Durham, North Carolina 27708  } \\
  $^{13}$ {\eightit Fermi National Accelerator Laboratory, Batavia, Illinois 60510  } \\
  $^{14}$ {\eightit University of Florida, Gainesville, Florida 32611  } \\
  $^{15}$ {\eightit Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica
Nucleare, I-00044 Frascati, Italy  } \\
  $^{16}$ {\eightit University of Geneva, CH-1211 Geneva 4, Switzerland  } \\
  $^{17}$ {\eightit Glasgow University, Glasgow G12 8QQ, United Kingdom  } \\
  $^{18}$ {\eightit Harvard University, Cambridge, Massachusetts 02138  } \\
  $^{19}$ {\eightit Hiroshima University, Higashi-Hiroshima 724, Japan  } \\
  $^{20}$ {\eightit University of Illinois, Urbana, Illinois 61801  } \\
  $^{21}$ {\eightit The Johns Hopkins University, Baltimore, Maryland 21218  } \\
  $^{22}$ {\eightit Institut f�r Experimentelle Kernphysik, Universit�t Karlsruhe,
76128 Karlsruhe, Germany  } \\
  $^{23}$ {\eightit Center for High Energy Physics: Kyungpook National University,
Taegu 702-701; Seoul National University, Seoul 151-742; and SungKyunKwan
University, Suwon 440-746; Korea  } \\
  $^{24}$ {\eightit High Energy Accelerator Research Organization (KEK), Tsukuba,
Ibaraki 305, Japan  } \\
  $^{25}$ {\eightit Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley,
California 94720  } \\
  $^{26}$ {\eightit University College London, London WC1E 6BT, United Kingdom  } \\
  $^{27}$ {\eightit Massachusetts Institute of Technology, Cambridge, Massachusetts
02139  } \\
  $^{28}$ {\eightit University of Michigan, Ann Arbor, Michigan 48109  } \\
  $^{29}$ {\eightit Michigan State University, East Lansing, Michigan 48824  } \\
  $^{30}$ {\eightit Institution for Theoretical and Experimental Physics, ITEP,,
Moscow 117259, Russia  } \\
  $^{31}$ {\eightit University of New Mexico, Albuquerque, New Mexico 87131  } \\
  $^{32}$ {\eightit Northwestern University, Evanston, Illinois 60208  } \\
  $^{33}$ {\eightit The Ohio State University, Columbus, Ohio 43210  } \\
  $^{34}$ {\eightit Osaka City University, Osaka 588, Japan  } \\
  $^{35}$ {\eightit University of Oxford, Oxford OX1 3RH, United Kingdom  } \\
  $^{36}$ {\eightit Universita di Padova, Istituto Nazionale di Fisica Nucleare,
Sezione di Padova, I-35131 Padova, Italy  } \\
  $^{37}$ {\eightit University of Pennsylvania, Philadelphia, Pennsylvania 19104  } \\
  $^{38}$ {\eightit Istituto Nazionale di Fisica Nucleare, University and Scuola
Normale Superiore of Pisa, I-56100 Pisa, Italy  } \\
  $^{39}$ {\eightit University of Pittsburgh, Pittsburgh, Pennsylvania 15260  } \\
  $^{40}$ {\eightit Purdue University, West Lafayette, Indiana 47907  } \\
  $^{41}$ {\eightit University of Rochester, Rochester, New York 14627  } \\
  $^{42}$ {\eightit Rockefeller University, New York, New York 10021  } \\
  $^{43}$ {\eightit Instituto Nazionale de Fisica Nucleare, Sezione di Roma, University di Roma I, "La Sapienza," I-00185 Roma, Italy  } \\
  $^{44}$ {\eightit Rutgers University, Piscataway, New Jersey 08855  } \\
  $^{45}$ {\eightit Texas A\&M University, College Station, Texas 77843  } \\
  $^{46}$ {\eightit Texas Tech University, Lubbock, Texas 79409  } \\
  $^{47}$ {\eightit Institute of Particle Physics, University of Toronto, Toronto
M5S 1A7, Canada  } \\
  $^{48}$ {\eightit Istituto Nazionale di Fisica Nucleare, University of
Trieste/Udine, Italy  } \\
  $^{49}$ {\eightit University of Tsukuba, Tsukuba, Ibaraki 305, Japan  } \\
  $^{50}$ {\eightit Tufts University, Medford, Massachusetts 02155  } \\
  $^{51}$ {\eightit Waseda University, Tokyo 169, Japan  } \\
  $^{52}$ {\eightit University of Wisconsin, Madison, Wisconsin 53706  } \\
  $^{53}$ {\eightit Yale University, New Haven, Connecticut 06520  } \\
%\end{center}
}

cdf_auth.tex
\author{
D.~Acosta,$^{14}$ T.~Affolder,$^{7}$ M.G.~Albrow,$^{13}$ D.~Ambrose,$^{36}$   
D.~Amidei,$^{27}$ K.~Anikeev,$^{26}$ J.~Antos,$^{1}$ 
G.~Apollinari,$^{13}$ T.~Arisawa,$^{50}$ A.~Artikov,$^{11}$ 
W.~Ashmanskas,$^{2}$ F.~Azfar,$^{34}$ P.~Azzi-Bacchetta,$^{35}$ 
N.~Bacchetta,$^{35}$ H.~Bachacou,$^{24}$ W.~Badgett,$^{13}$
A.~Barbaro-Galtieri,$^{24}$ 
V.E.~Barnes,$^{39}$ B.A.~Barnett,$^{21}$ S.~Baroiant,$^{5}$ M.~Barone,$^{15}$  
G.~Bauer,$^{26}$ F.~Bedeschi,$^{37}$ S.~Behari,$^{21}$ S.~Belforte,$^{47}$
W.H.~Bell,$^{17}$
G.~Bellettini,$^{37}$ J.~Bellinger,$^{51}$ D.~Benjamin,$^{12}$ 
A.~Beretvas,$^{13}$ A.~Bhatti,$^{41}$ M.~Binkley,$^{13}$ 
D.~Bisello,$^{35}$ M.~Bishai,$^{13}$ R.E.~Blair,$^{2}$ C.~Blocker,$^{4}$ 
K.~Bloom,$^{27}$ B.~Blumenfeld,$^{21}$ A.~Bocci,$^{41}$ 
A.~Bodek,$^{40}$ G.~Bolla,$^{39}$ A.~Bolshov,$^{26}$   
D.~Bortoletto,$^{39}$ J.~Boudreau,$^{38}$ 
C.~Bromberg,$^{28}$ E.~Brubaker,$^{24}$   
J.~Budagov,$^{11}$ H.S.~Budd,$^{40}$ K.~Burkett,$^{13}$ 
G.~Busetto,$^{35}$ K.L.~Byrum,$^{2}$ S.~Cabrera,$^{12}$ M.~Campbell,$^{27}$ 
W.~Carithers,$^{24}$ D.~Carlsmith,$^{51}$  
A.~Castro,$^{3}$ D.~Cauz,$^{47}$ A.~Cerri,$^{24}$ L.~Cerrito,$^{20}$ 
J.~Chapman,$^{27}$ C.~Chen,$^{36}$ Y.C.~Chen,$^{1}$ 
M.~Chertok,$^{5}$ 
G.~Chiarelli,$^{37}$ G.~Chlachidze,$^{13}$
F.~Chlebana,$^{13}$ M.L.~Chu,$^{1}$ J.Y.~Chung,$^{32}$ 
W.-H.~Chung,$^{51}$ Y.S.~Chung,$^{40}$ C.I.~Ciobanu,$^{20}$ 
A.G.~Clark,$^{16}$ M.~Coca,$^{40}$ A.~Connolly,$^{24}$ 
M.~Convery,$^{41}$ J.~Conway,$^{43}$ M.~Cordelli,$^{15}$ J.~Cranshaw,$^{45}$
R.~Culbertson,$^{13}$ D.~Dagenhart,$^{4}$ S.~D'Auria,$^{17}$ P.~de~Barbaro,$^{40}$
S.~De~Cecco,$^{42}$ S.~Dell'Agnello,$^{15}$ M.~Dell'Orso,$^{37}$ 
S.~Demers,$^{40}$ L.~Demortier,$^{41}$ M.~Deninno,$^{3}$   D.~De~Pedis,$^{42}$ 
P.F.~Derwent,$^{13}$ 
C.~Dionisi,$^{42}$ J.R.~Dittmann,$^{13}$ A.~Dominguez,$^{24}$ 
S.~Donati,$^{37}$ M.~D'Onofrio,$^{16}$ T.~Dorigo,$^{35}$
N.~Eddy,$^{20}$ R.~Erbacher,$^{13}$ 
D.~Errede,$^{20}$ S.~Errede,$^{20}$ R.~Eusebi,$^{40}$  
S.~Farrington,$^{17}$ R.G.~Feild,$^{52}$
J.P.~Fernandez,$^{39}$ C.~Ferretti,$^{27}$ R.D.~Field,$^{14}$
I.~Fiori,$^{37}$ B.~Flaugher,$^{13}$ L.R.~Flores-Castillo,$^{38}$ 
G.W.~Foster,$^{13}$ M.~Franklin,$^{18}$ J.~Friedman,$^{26}$  
I.~Furic,$^{26}$  
M.~Gallinaro,$^{41}$ M.~Garcia-Sciveres,$^{24}$ 
A.F.~Garfinkel,$^{39}$ C.~Gay,$^{52}$ 
D.W.~Gerdes,$^{27}$ E.~Gerstein,$^{9}$ S.~Giagu,$^{42}$ P.~Giannetti,$^{37}$ 
K.~Giolo,$^{39}$ M.~Giordani,$^{47}$ P.~Giromini,$^{15}$ 
V.~Glagolev,$^{11}$ D.~Glenzinski,$^{13}$ M.~Gold,$^{30}$ 
N.~Goldschmidt,$^{27}$  
J.~Goldstein,$^{34}$ G.~Gomez,$^{8}$ M.~Goncharov,$^{44}$
I.~Gorelov,$^{30}$  A.T.~Goshaw,$^{12}$ Y.~Gotra,$^{38}$ K.~Goulianos,$^{41}$ 
A.~Gresele,$^{3}$   C.~Grosso-Pilcher,$^{10}$ M.~Guenther,$^{39}$
J.~Guimaraes~da~Costa,$^{18}$ C.~Haber,$^{24}$
S.R.~Hahn,$^{13}$ E.~Halkiadakis,$^{40}$
R.~Handler,$^{51}$
F.~Happacher,$^{15}$ K.~Hara,$^{48}$   
R.M.~Harris,$^{13}$ F.~Hartmann,$^{22}$ K.~Hatakeyama,$^{41}$ J.~Hauser,$^{6}$  
J.~Heinrich,$^{36}$ M.~Hennecke,$^{22}$ M.~Herndon,$^{21}$ 
C.~Hill,$^{7}$ A.~Hocker,$^{40}$ K.D.~Hoffman,$^{10}$ 
S.~Hou,$^{1}$ B.T.~Huffman,$^{34}$ R.~Hughes,$^{32}$  
J.~Huston,$^{28}$ C.~Issever,$^{7}$
J.~Incandela,$^{7}$ G.~Introzzi,$^{37}$ M.~Iori,$^{42}$ A.~Ivanov,$^{40}$ 
Y.~Iwata,$^{19}$ B.~Iyutin,$^{26}$
E.~James,$^{13}$ M.~Jones,$^{39}$  
T.~Kamon,$^{44}$ J.~Kang,$^{27}$ M.~Karagoz~Unel,$^{31}$ 
S.~Kartal,$^{13}$ H.~Kasha,$^{52}$ Y.~Kato,$^{33}$ 
R.D.~Kennedy,$^{13}$ R.~Kephart,$^{13}$ 
B.~Kilminster,$^{40}$ D.H.~Kim,$^{23}$ H.S.~Kim,$^{20}$ 
M.J.~Kim,$^{9}$ S.B.~Kim,$^{23}$ 
S.H.~Kim,$^{48}$ T.H.~Kim,$^{26}$ Y.K.~Kim,$^{10}$ M.~Kirby,$^{12}$ 
L.~Kirsch,$^{4}$ S.~Klimenko,$^{14}$ P.~Koehn,$^{32}$ 
K.~Kondo,$^{50}$ J.~Konigsberg,$^{14}$ 
A.~Korn,$^{26}$ A.~Korytov,$^{14}$ 
J.~Kroll,$^{36}$ M.~Kruse,$^{12}$ V.~Krutelyov,$^{44}$ S.E.~Kuhlmann,$^{2}$ 
N.~Kuznetsova,$^{13}$ 
A.T.~Laasanen,$^{39}$ 
S.~Lami,$^{41}$ S.~Lammel,$^{13}$ J.~Lancaster,$^{12}$ K.~Lannon,$^{32}$ 
M.~Lancaster,$^{25}$ R.~Lander,$^{5}$ A.~Lath,$^{43}$  G.~Latino,$^{30}$ 
T.~LeCompte,$^{2}$ Y.~Le,$^{21}$ J.~Lee,$^{40}$ S.W.~Lee,$^{44}$ 
N.~Leonardo,$^{26}$ S.~Leone,$^{37}$ 
J.D.~Lewis,$^{13}$ K.~Li,$^{52}$ C.S.~Lin,$^{13}$ M.~Lindgren,$^{6}$ 
T.M.~Liss,$^{20}$ 
T.~Liu,$^{13}$ D.O.~Litvintsev,$^{13}$  
N.S.~Lockyer,$^{36}$ A.~Loginov,$^{29}$ M.~Loreti,$^{35}$ D.~Lucchesi,$^{35}$  
P.~Lukens,$^{13}$ L.~Lyons,$^{34}$ J.~Lys,$^{24}$ 
R.~Madrak,$^{18}$ K.~Maeshima,$^{13}$ 
P.~Maksimovic,$^{21}$ L.~Malferrari,$^{3}$   M.~Mangano,$^{37}$ G.~Manca,$^{34}$
M.~Mariotti,$^{35}$ M.~Martin,$^{21}$
A.~Martin,$^{52}$ V.~Martin,$^{31}$ M.~Mart\'\i nez,$^{13}$ P.~Mazzanti,$^{3}$   
K.S.~McFarland,$^{40}$ P.~McIntyre,$^{44}$  
M.~Menguzzato,$^{35}$ A.~Menzione,$^{37}$ P.~Merkel,$^{13}$
C.~Mesropian,$^{41}$ A.~Meyer,$^{13}$ T.~Miao,$^{13}$ 
R.~Miller,$^{28}$ J.S.~Miller,$^{27}$ 
S.~Miscetti,$^{15}$ G.~Mitselmakher,$^{14}$ N.~Moggi,$^{3}$   R.~Moore,$^{13}$ 
T.~Moulik,$^{39}$ 
M.~Mulhearn,$^{26}$ A.~Mukherjee,$^{13}$ T.~Muller,$^{22}$ 
A.~Munar,$^{36}$ P.~Murat,$^{13}$  
J.~Nachtman,$^{13}$ S.~Nahn,$^{52}$ 
I.~Nakano,$^{19}$ R.~Napora,$^{21}$ F.~Niell,$^{27}$ C.~Nelson,$^{13}$ T.~Nelson,$^{13}$ 
C.~Neu,$^{32}$ M.S.~Neubauer,$^{26}$  
$\mbox{C.~Newman-Holmes}^{13}$ T.~Nigmanov,$^{38}$
L.~Nodulman,$^{2}$ S.H.~Oh,$^{12}$ Y.D.~Oh,$^{23}$ T.~Ohsugi,$^{19}$
T.~Okusawa,$^{33}$ W.~Orejudos,$^{24}$ C.~Pagliarone,$^{37}$ 
F.~Palmonari,$^{37}$ R.~Paoletti,$^{37}$ V.~Papadimitriou,$^{45}$ 
J.~Patrick,$^{13}$ 
G.~Pauletta,$^{47}$ M.~Paulini,$^{9}$ T.~Pauly,$^{34}$ C.~Paus,$^{26}$ 
D.~Pellett,$^{5}$ A.~Penzo,$^{47}$ T.J.~Phillips,$^{12}$ G.~Piacentino,$^{37}$
J.~Piedra,$^{8}$ K.T.~Pitts,$^{20}$ A.~Pompo\v{s},$^{39}$ L.~Pondrom,$^{51}$ 
G.~Pope,$^{38}$ T.~Pratt,$^{34}$ F.~Prokoshin,$^{11}$ J.~Proudfoot,$^{2}$
F.~Ptohos,$^{15}$ O.~Poukhov,$^{11}$ G.~Punzi,$^{37}$ J.~Rademacker,$^{34}$
A.~Rakitine,$^{26}$ F.~Ratnikov,$^{43}$ H.~Ray,$^{27}$ A.~Reichold,$^{34}$ 
P.~Renton,$^{34}$ M.~Rescigno,$^{42}$  
F.~Rimondi,$^{3}$   L.~Ristori,$^{37}$ W.J.~Robertson,$^{12}$ 
T.~Rodrigo,$^{8}$ S.~Rolli,$^{49}$  
L.~Rosenson,$^{26}$ R.~Roser,$^{13}$ R.~Rossin,$^{35}$ C.~Rott,$^{39}$  
A.~Roy,$^{39}$ A.~Ruiz,$^{8}$ D.~Ryan,$^{49}$ A.~Safonov,$^{5}$ R.~St.~Denis,$^{17}$ 
W.K.~Sakumoto,$^{40}$ D.~Saltzberg,$^{6}$ C.~Sanchez,$^{32}$ 
A.~Sansoni,$^{15}$ L.~Santi,$^{47}$ S.~Sarkar,$^{42}$  
P.~Savard,$^{46}$ A.~Savoy-Navarro,$^{13}$ P.~Schlabach,$^{13}$ 
E.E.~Schmidt,$^{13}$ M.P.~Schmidt,$^{52}$ M.~Schmitt,$^{31}$ 
L.~Scodellaro,$^{35}$ A.~Scribano,$^{37}$ A.~Sedov,$^{39}$   
S.~Seidel,$^{30}$ Y.~Seiya,$^{48}$ A.~Semenov,$^{11}$
F.~Semeria,$^{3}$   M.D.~Shapiro,$^{24}$ 
P.F.~Shepard,$^{38}$ T.~Shibayama,$^{48}$ M.~Shimojima,$^{48}$ 
M.~Shochet,$^{10}$ A.~Sidoti,$^{35}$ A.~Sill,$^{45}$ 
P.~Sinervo,$^{46}$ A.J.~Slaughter,$^{52}$ K.~Sliwa,$^{49}$
F.D.~Snider,$^{13}$ R.~Snihur,$^{25}$  
M.~Spezziga,$^{45}$  
F.~Spinella,$^{37}$ M.~Spiropulu,$^{7}$ L.~Spiegel,$^{13}$ 
A.~Stefanini,$^{37}$ 
J.~Strologas,$^{30}$ D.~Stuart,$^{7}$ A.~Sukhanov,$^{14}$
K.~Sumorok,$^{26}$ T.~Suzuki,$^{48}$ R.~Takashima,$^{19}$ 
K.~Takikawa,$^{48}$ M.~Tanaka,$^{2}$   
M.~Tecchio,$^{27}$ R.J.~Tesarek,$^{13}$ P.K.~Teng,$^{1}$ 
K.~Terashi,$^{41}$ S.~Tether,$^{26}$ J.~Thom,$^{13}$ A.S.~Thompson,$^{17}$ 
E.~Thomson,$^{32}$ P.~Tipton,$^{40}$ S.~Tkaczyk,$^{13}$ D.~Toback,$^{44}$
K.~Tollefson,$^{28}$ D.~Tonelli,$^{37}$ M.~T\"{o}nnesmann,$^{28}$ 
H.~Toyoda,$^{33}$
W.~Trischuk,$^{46}$  
J.~Tseng,$^{26}$ D.~Tsybychev,$^{14}$ N.~Turini,$^{37}$   
F.~Ukegawa,$^{48}$ T.~Unverhau,$^{17}$ T.~Vaiciulis,$^{40}$
A.~Varganov,$^{27}$ E.~Vataga,$^{37}$
S.~Vejcik~III,$^{13}$ G.~Velev,$^{13}$ G.~Veramendi,$^{24}$   
R.~Vidal,$^{13}$ I.~Vila,$^{8}$ R.~Vilar,$^{8}$ I.~Volobouev,$^{24}$ 
M.~von~der~Mey,$^{6}$ R.G.~Wagner,$^{2}$ R.L.~Wagner,$^{13}$ 
W.~Wagner,$^{22}$ Z.~Wan,$^{43}$ C.~Wang,$^{12}$
M.J.~Wang,$^{1}$ S.M.~Wang,$^{14}$ B.~Ward,$^{17}$ S.~Waschke,$^{17}$ 
D.~Waters,$^{25}$ T.~Watts,$^{43}$
M.~Weber,$^{24}$ W.C.~Wester~III,$^{13}$ B.~Whitehouse,$^{49}$
A.B.~Wicklund,$^{2}$ E.~Wicklund,$^{13}$   
H.H.~Williams,$^{36}$ P.~Wilson,$^{13}$ 
B.L.~Winer,$^{32}$ S.~Wolbers,$^{13}$ 
M.~Wolter,$^{49}$
S.~Worm,$^{43}$ X.~Wu,$^{16}$ F.~W\"urthwein,$^{26}$ 
U.K.~Yang,$^{10}$ W.~Yao,$^{24}$ G.P.~Yeh,$^{13}$ K.~Yi,$^{21}$ 
J.~Yoh,$^{13}$ T.~Yoshida,$^{33}$  
I.~Yu,$^{23}$ S.~Yu,$^{36}$ J.C.~Yun,$^{13}$ L.~Zanello,$^{42}$
A.~Zanetti,$^{47}$ F.~Zetti,$^{24}$ and S.~Zucchelli,$^{3}$
}

%\begin{center}
%(CDF Collaboration)
%\end{center}

\affiliation{
$^{1}$  {\eightit Institute of Physics, Academia Sinica, Taipei, Taiwan 11529, Republic of China} \\
$^{2}$  {\eightit Argonne National Laboratory, Argonne, Illinois 60439} \\
$^{3}$  {\eightit Istituto Nazionale di Fisica Nucleare, University of
Bologna, I-40127 Bologna, Italy} \\
$^{4}$  {\eightit Brandeis University, Waltham, Massachusetts 02254} \\
$^{5}$  {\eightit University of California at Davis, Davis, California  95616} \\
$^{6}$  {\eightit University of California at Los Angeles, Los Angeles, California  90024} \\ 
$^{7}$  {\eightit University of California at Santa Barbara, Santa Barbara, California 93106} \\ 
$^{8}$ {\eightit Instituto de Fisica de Cantabria, CSIC-University of
Cantabria, 39005 Santander, Spain} \\
$^{9}$  {\eightit Carnegie Mellon University, Pittsburgh, Pennsylvania  15213} \\
$^{10}$ {\eightit Enrico Fermi Institute, University of Chicago, Chicago, 
Illinois 60637} \\
$^{11}$  {\eightit Joint Institute for Nuclear Research, RU-141980 Dubna, Russia} \\
$^{12}$ {\eightit Duke University, Durham, North Carolina  27708} \\
$^{13}$ {\eightit Fermi National Accelerator Laboratory, Batavia, Illinois
60510} \\
$^{14}$ {\eightit University of Florida, Gainesville, Florida  32611} \\
$^{15}$ {\eightit Laboratori Nazionali di Frascati, Istituto Nazionale di
Fisica Nucleare, I-00044 Frascati, Italy} \\
$^{16}$ {\eightit University of Geneva, CH-1211 Geneva 4, Switzerland} \\
$^{17}$ {\eightit Glasgow University, Glasgow G12 8QQ, United Kingdom}\\
$^{18}$ {\eightit Harvard University, Cambridge, Massachusetts 02138} \\
$^{19}$ {\eightit Hiroshima University, Higashi-Hiroshima 724, Japan} \\
$^{20}$ {\eightit University of Illinois, Urbana, Illinois 61801} \\
$^{21}$ {\eightit The Johns Hopkins University, Baltimore, Maryland 21218} \\
$^{22}$ {\eightit Institut f\"{u}r Experimentelle Kernphysik, 
Universit\"{a}t Karlsruhe, 76128 Karlsruhe, Germany} \\
$^{23}$ {\eightit Center for High Energy Physics: Kyungpook National
University, Taegu 702-701; Seoul National University, Seoul 151-742; and
SungKyunKwan University, Suwon 440-746; Korea} \\
$^{24}$ {\eightit Ernest Orlando Lawrence Berkeley National Laboratory, 
Berkeley, California 94720} \\
$^{25}$ {\eightit University College London, London WC1E 6BT, United Kingdom} \\
$^{26}$ {\eightit Massachusetts Institute of Technology, Cambridge,
Massachusetts  02139} \\   
$^{27}$ {\eightit University of Michigan, Ann Arbor, Michigan 48109} \\
$^{28}$ {\eightit Michigan State University, East Lansing, Michigan  48824} \\
$^{29}$ {\eightit Institution for Theoretical and Experimental Physics, ITEP,
Moscow 117259, Russia} \\
$^{30}$ {\eightit University of New Mexico, Albuquerque, New Mexico 87131} \\
$^{31}$ {\eightit Northwestern University, Evanston, Illinois  60208} \\
$^{32}$ {\eightit The Ohio State University, Columbus, Ohio  43210} \\
$^{33}$ {\eightit Osaka City University, Osaka 588, Japan} \\
$^{34}$ {\eightit University of Oxford, Oxford OX1 3RH, United Kingdom} \\
$^{35}$ {\eightit Universita di Padova, Istituto Nazionale di Fisica 
          Nucleare, Sezione di Padova, I-35131 Padova, Italy} \\
$^{36}$ {\eightit University of Pennsylvania, Philadelphia, 
        Pennsylvania 19104} \\   
$^{37}$ {\eightit Istituto Nazionale di Fisica Nucleare, University and Scuola
               Normale Superiore of Pisa, I-56100 Pisa, Italy} \\
$^{38}$ {\eightit University of Pittsburgh, Pittsburgh, Pennsylvania 15260} \\
$^{39}$ {\eightit Purdue University, West Lafayette, Indiana 47907} \\
$^{40}$ {\eightit University of Rochester, Rochester, New York 14627} \\
$^{41}$ {\eightit Rockefeller University, New York, New York 10021} \\
$^{42}$ {\eightit Instituto Nazionale de Fisica Nucleare, Sezione di Roma,
University di Roma I, ``La Sapienza," I-00185 Roma, Italy}\\
$^{43}$ {\eightit Rutgers University, Piscataway, New Jersey 08855} \\
$^{44}$ {\eightit Texas A\&M University, College Station, Texas 77843} \\
$^{45}$ {\eightit Texas Tech University, Lubbock, Texas 79409} \\
$^{46}$ {\eightit Institute of Particle Physics, University of Toronto, Toronto
M5S 1A7, Canada} \\
$^{47}$ {\eightit Istituto Nazionale di Fisica Nucleare, University of Trieste/\
Udine, Italy} \\
$^{48}$ {\eightit University of Tsukuba, Tsukuba, Ibaraki 305, Japan} \\
$^{49}$ {\eightit Tufts University, Medford, Massachusetts 02155} \\
$^{50}$ {\eightit Waseda University, Tokyo 169, Japan} \\
$^{51}$ {\eightit University of Wisconsin, Madison, Wisconsin 53706} \\
$^{52}$ {\eightit Yale University, New Haven, Connecticut 06520} \\
}

data.tex
%auto-ignore
%\section{Data samples}


The present study uses data from $p\bar{p}$ collisions at $\sqrt{s} = 1.8$
TeV collected by the Collider Detector at Fermilab (CDF)\cite{CDF} during the
period 1992-1995 (Run I). The integrated luminosity of the data sample is 109
$\pm$ 7 pb$^{-1}$.  Events were selected \cite{toplj,topdi} and assigned to
three different $t\bar{t}$ subsamples chosen for their low background and
high efficiency for $b$ jet identification.  Each sample is classified by the
number of leptons and identified $b$ jets in the final state.
%The $t\bar{t}$ data samples are obtained from an integrated luminosity of 109
%$\pm$ 7 pb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV collected
%from Run I (1992-1995) at the Tevatron and observed
%in the CDF detector \cite{CDF}.  Three sub-samples of $t\bar{t}$ data
%previously used in the measurement of the top quark mass~\cite{toplj,topdi}
%are chosen for their low background and high efficiency for $b$ jet
%identification.  

The ``dilepton'' sample is dominated by $t\bar{t}$ in which both $W$ bosons
decay to an electron or muon and neutrinos.  Events are selected by
requiring $\MET >$ 25 GeV, one muon and one electron of opposite charge with
$P_T > 20$ GeV in the central pseudo-rapidity region ($|\eta| < 1.0$) \cite{eta}, and two jets with
$E_T > 10$ GeV and $|\eta| < 2.0$.  This is a subsample of the
dilepton events used in other analyses~\cite{topdi}, considering only $e +
\mu + jets$ events in order to remove the dominant background, 
which is Drell-Yan production of $ee$ or $\mu\mu$.
%Using only $e\mu$ dilepton events, which is expected to
%account for 58 $\pm$ 2 \% of the total dilepton event acceptance, has
%an advantage since in the standard top dilepton analyses, reducing
%background from 2.4 $\pm$ 0.5 to 0.76 $\pm$ 0.21, while reducing the
%expected signal from 4.7 to 2.8.  
The significant remaining backgrounds are decays to electron and muon of $Z
\to \tau \tau$, $WW$ in association with extra jets, and $W$ production
associated with three or more jets, where one jet is misidentified as an
electron or a muon.  No attempt is made to identify $b$ jets explicitly.
However, initial and final state gluon radiation can result in extra jets, so
the $b$ jets are assumed to be the two highest $E_T$ jets, which is correct
in $\sim$80 \% of dilepton events.  There are four $M_{\ell b}$ combinations in
each dilepton event.

The other two samples used in the analysis require only one $W$ to decay into
an electron or muon and a neutrino and the other $W$ to decay hadronically
(``lepton+jets'').  These events are selected by requiring one electron or
muon with $P_T >$ 20 GeV, in the central region as above.  At least four jets
are required, three of which must have $E_T >$ 15 GeV, $|\eta| < 2.0$, and
the fourth must have $E_T >$ 8 GeV and $|\eta| < 2.4$. The background for
these events consists predominantly of direct production of a $W$ plus extra
jets and its behavior is modeled with the VECBOS generator \cite{VECBOS}.  To
reduce the background, at least one jet must be identified as a $b$ candidate
($b$-tagged) with a topological algorithm requiring tracks in the jet
reconstructed with the silicon vertex (SVX) detector to form a secondary
vertex \cite{toplj,oldtopresults}.  This requirement is 48 \%
efficient for tagging at least one $b$ jet in a $t\bar{t}$ event
\cite{cdf_mass_prd}.  Without any $b$-tag, the expected signal to background
ratio ($S/B$) of the sample is 0.4, whereas requiring one $b$-tag improves
$S/B$ to 5.3.  The $b$-tag also selects the jet to be paired with the lepton
to form $M_{\ell b}$.  Events with a single $b$-tagged jet comprise the
``single-tagged'' sample, and have one measured $M_{\ell b}$ which is correct
half the time. Events with both $b$ quarks tagged make up the
``double-tagged'' sample, have a $S/B$ of 24, and provide two $M_{\ell b}$
pairings, at least one of which combines the wrong $b$ with the $\ell$.

A total of 7 events were found in the dilepton $e \mu$ sample
with an expected background of 0.76 $\pm$ 0.21 events. In the
single-tagged sample 15 events were found with a background 2.0 $\pm$
0.7, and in the double-tagged sample there were 5 events with a 0.2
$\pm$ 0.2 background.  Note that since right-handed
leptons have higher $P_T$, an increase in events passing the lepton
$P_T$ trigger requirement could also indicate a V$+$A theory.  However,
any potential observed rate increase would be deemed to be {\em a posteriori}
knowledge from the point of view of this analysis, and therefore only the
shape of the $M^2_{\ell b}$ distributions is considered.


introduction.tex
%auto-ignore
%\section{Introduction}

%
The large value of the top quark mass has led to speculation that the top
quark could play a role in the mechanism of the electroweak symmetry breaking
\cite{hill}.  If so, the electroweak interactions of the top quark could be
modified \cite{Peccei:kr}.  Such a modification could alter the V$-$A
structure of the $tbW$ interaction which in turn would lead to an altered $W$
polarization in top decay \cite{Kane:1991bg,Jezabek:1994zv,Nelson:1997xd}.
Possible scenarios that would introduce a V$+$A contribution to the $tbW$
vertex include $SU(2)_L \times SU(2)_R$ extensions of the standard model
\cite{review}.  One such model invokes new mirror particles to assist a
top-condensate in breaking electroweak symmetry \cite{triant}. The theory of
``beautiful mirror'' fermions predicts a fourth generation up-type quark with
right-handed weak interactions which could contaminate the top sample or
induce a right-handed top electroweak interaction by mixing with the top
quark
\cite{Choudhury:2001hs}.

Indirect limits of right-handed $t \to b W$
currents have been placed using the process $b \to s \gamma$,
which proceeds via an electroweak radiative penguin process \cite{cleo}.
These limits are stringent, but scenarios can be envisaged where other
contributions to $b \to s \gamma$ might invalidate these bounds.
%lead to an invalidation of these
%bounds.  
The goal of this study is a direct measurement of the $tbW$ vertex
from the electroweak decay of top.

The spin-one $W$ has three possible helicities; for the $W^+$ we label
these as $-1$ (left-handed), 0 (longitudinal), and $+1$ (right-handed),
with the opposite convention for the $W^-$.  Because $M_t>M_W$, a
large fraction of the $W$ bosons produced in top decay will be
longitudinally polarized \cite{Kane:1991bg}.  The fraction is given by
\begin{equation}
F_0 = \frac{M_t^2/M_W^2}{(M_t^2/M_W^2+2)}.
\end{equation}
%For the current values of $M_t= 178.0 \pm 4.3$~GeV and $M_W = 80.425 \pm
%0.038$~GeV \cite{new_combo}, this corresponds to $F_{0}=0.71 \pm
%0.01$. 
For the current values of $M_t= 174.3 \pm 5.1$~GeV and $M_W = 80.425 \pm
0.038$~GeV \cite{pdg_masses}, this corresponds to $F_{0}=0.70 \pm
0.01$. 
If there were a
non-standard model V$+$A contribution to the top decay vertex, such
contribution would not
decrease the branching ratio to longitudinal $W$ bosons but would
instead decrease the branching ratio to left-handed $W$ bosons, replacing
some of this rate with an enhanced right-handed component.  

Leptons from the decay of longitudinally polarized $W$ bosons have a
symmetric angular distribution of the form $1-(\cos\psi_{\ell}^{\star})^2$,
where $\psi_{\ell}^{\star}$ is defined as the angle in the $W$ rest frame
between the lepton and the boost vector ($\vec{\beta}$) from the top
rest frame to the $W$ rest frame.  Maximal parity violation in the
V$-$A electroweak theory predicts that the non-longitudinal $W$
helicity is purely left-handed in the limit of massless final
state fermions.  This creates an asymmetric angular distribution of
the form $(1-\cos\psi_{\ell}^{\star})^2$ \cite{Kane:1991bg}.  Due to angular
momentum conservation, even though the massive top quark may be left- or
right-handed, positively polarized $W^{+}$ bosons are not
possible since a massless $b$ quark must be left-handed.  A small right-handed
component (0.04 \%) of the form $(1+\cos\psi_{\ell}^{\star})^2$ results
when the mass of the $b$ quark is considered.  

\begin{figure}
\resizebox{0.9\columnwidth}{!}{\includegraphics{mass_plot_v3}}
\caption{The theoretical distributions of $M_{\ell b}^2$ for purely V$-$A and
V$+$A hypotheses, using the correct lepton-$b$ pairing.  The $M_{\ell b}^2$ can
be used to discriminate between the two hypotheses as it peaks at higher
values for V$+$A. This ideal case does not include detector and trigger
effects or the intrinsic lepton-$b$ mass resolution.}
\label{fig:vma_vpa}
\end{figure}

This analysis exploits the relationship between the angle
$\psi_{\ell}^{\star}$ and the invariant mass of the $\ell b$ pair, produced in
the top decay chain $t \to W b$, $W \to \ell \nu$ to determine the polarization
of the $W$ boson.  
%This measurement cannot be easily
%done in the hadronic decay channel of the $W$ because it is necessary to know the
%weak isospin of particles in the final state in order to relate the two body
%invariant mass to $W$ polarization.  
The angle $\psi_{\ell}^\star$ can be
related to the $\ell b$ invariant mass by
\begin{equation}
M_{\ell b}^2 = \frac{1}{2} (M_{t}^2 -  M_{W}^2)(1 + \cos\psi_\ell^\star).
\label{eq:m2cos}
\end{equation}

In the V$-$A theory, the lepton and $b$ jet in the $W$ rest
frame tend to move in the same direction, but in a V$+$A decay, the lepton
and $b$ jet typically move in opposite directions.  Therefore, $M_{\ell
b}^2$ would be larger on average from a V$+$A contribution as shown in
Fig.~\ref{fig:vma_vpa}.  This difference can be used to determine $f_{V+A}$,
the fraction of $t$ quarks which decay with a V$+$A interaction.  

%
If the interaction has both V$-$A and V$+$A contributions, the
total angular distribution will be approximately described by summing
over weighted linear combinations of the above angular distributions.
The summing of rates correctly describes the angular distribution from
longitudinal and either a pure V$+$A or V$-$A distribution; however, if
there is a combination of V$-$A and V$+$A interactions, they may 
interfere with some relative phase.
% which is unknown since there is
%no model to describe a V$+$A interaction.  
The present analysis neglects this interference, which would have the largest
impact for $f_{V+A} = 0.5$. These interference effects are only of
order $1/\gamma_b$, the boost of the $b$ quark in the top rest frame, and
therefore are estimated to affect the angular distributions \cite{Tim} at no
more than the 10\% level.  The associated uncertainty is therefore not
significant compared to expected statistical and systematic uncertainties.

Experimentally, $M_{\ell b}^2$ is a reliable observable in $t\bar{t}$ decay
at a hadron collider because no information about the top or $W$ rest frames
is required, and therefore the unknown boost of the $t\bar{t}$ system along
the beam direction does not disrupt the measurement.  This technique also
avoids the need to rely on the missing transverse energy ($\MET$) due to the
neutrino. The $\MET$ is poorly measured compared to other kinematic
quantities in the event and is ambiguous in events with two final state
neutrinos, e.g., both $W^+$ and $W^-$ from the $t\bar{t}$ decay leptonically.




method.tex
%auto-ignore
%\section{Experimental Method}

%


The $M_{\ell b}^2$ distributions of the data are fit to a linear combination of
three predicted $M_{\ell b}^2$ distributions: $t\bar{t}$ production with a V$-$A
interaction, $t\bar{t}$ production with a V$+$A interaction, and background.  The fit maximizes
a binned likelihood as a function of $f_{V+A}$.  
%No term
%for the overall normalization of the data sample is included in the
%likelihood because this analysis was conceived after the sizes of
%these samples were already known, and cross-sections based on them had
%been derived.  
Likelihood scans are performed both inside and outside
the physical region of $[0,1]$ in $f_{V+A}$, and the level of
backgrounds in each fit is allowed to vary within the estimated
uncertainties.



The predicted $M_{\ell b}$ distributions are calculated separately for
dilepton, single-tagged, and double-tagged data samples, by Monte Carlo
simulations of $t\bar{t}$ and background. The effects of predicted
kinematics, decay distributions, detector acceptance, and resolution are all
considered.  The HERWIG event generator~\cite{herwig} with the MRST h-g PDF
set~\cite{MRST} was used to model $t\bar{t}$ production.


%% Ben, these two are basically ``we did it correctly'' details which won't
%% help anyone reading it except the authors... :-)
%The background and V$-$A $t\bar{t}$ samples are weighted by the relative
%efficiency for the events to pass the lepton $P_T$ requirements as
%compared to the V$+$A sample which has a harder lepton $P_T$
%distribution.  
%The likelihood fit technique is evaluated using Monte
%Carlo experiments and determined to be consistent with Gaussian
%central value and errors by including a 4\% scale factor to the error
%of the fit.

%
For cases with two possible $b$ jets that can be matched to a
lepton (the dilepton and double-tagged samples), the fit is performed to
two-dimensional distributions of $M^2_{\ell b_{(1)}}$ and $M^2_{\ell
b_{(2)}}$, thus taking into account that only one can be correct.  Naively,
this ambiguity in assignments of leptons and $b$ quarks to one top quark
would appear to be problematic in this measurement.  However, while correct
pairings are limited kinematically by $M_t^2 - M_W^2$ for a massless $b$
quark, incorrect pairings often have significantly higher mass.  With our two
dimensional fit, mispairings only increase the statistical
uncertainty in the fit by only 15\%.

\begin{table}
  \begin{tabular}{|c|c|}
   \hline
   \multicolumn{2}{|c|}{Systematic Uncertainties}\\  
   \hline
   Top mass                        &    0.19  
%\emph{(0.21 w/out jet energy correlation)}
                                              \\
   Jet energy scale                &    0.04  
%\emph{(0.14 w/out top mass correlation)} 
                                              \\
   Background shape                &    0.05  \\
   Background normalization        &    0.05  \\
   ISR gluon radiation             &    0.04  \\
   FSR gluon radiation             &    0.03  \\
   B tagging efficiency            &    0.03  \\
   Parton distribution functions   &    0.02  \\
   Monte Carlo statistics          &    0.01  \\
   Relative acceptance             &    0.005  \\
   \hline
   Total  systematic  &     0.21     \\
   \hline
   \end{tabular}
\caption{Summary of systematic uncertainties in terms of the shift in
measurement of the V$+$A
  fraction.  The systematic uncertainties shown for the top mass and jet
energy scale are after considering the correlations between the two; without these corrections the systematic uncertainties are $0.21$ and $0.14$, respectively.}
\label{table:system}
\end{table}

%
Systematic uncertainties in the measurement enter the analysis primarily
through the prediction of the $M_{\ell b}$ distributions, and are evaluated
by changing assumptions in the Monte Carlo simulation.  Listed individually
in Table~\ref{table:system}, all systematic uncertainties added in quadrature
represent a $0.21$ uncertainty in $f_{V+A}$.  The largest systematic
uncertainties are from the top mass and the jet energy scale.  Increasing the
top mass will increase $M_{\ell b}$ in top decay.  The measured uncertainty
of the top quark mass is $5.1$~GeV~\cite{combination}, and an increase
in top mass by one standard deviation increases $f_{V+A}$ by $0.19$.  
Sources of systematic uncertainty in the jet energy scale include the
calibration of the calorimeter, the simulation of the calorimeter response
and the modeling of fragmentation~\cite{toplj}.  An increase in the overall
jet energy scale by one standard deviation would increase $f_{V+A}$ by
$0.14$.  However, the CDF jet energy scale has a large effect on the world
average top mass measurement.  Accounting for the correlation between
these two effects results in a reduction of the systematic from jet energy
scale to 0.04.

Smaller sources of systematic uncertainties were studied in
this measurement by observing the effect in simulated
pseudoexperiments.  
%
Hard gluon bremsstrahlung either in the
initial or final state can cause
significant mismeasurement of the $b$ quark jet or can produce a jet
which can be mistaken for the $b$ quark jet itself.  The size of the
effect was conservatively estimated by removing all such events from the
sample in a simulated measurement. 
%
For samples where SVX topological $b$ tagging was used, the effect of
uncertainties in $b$ tagging efficiency as a function of $b$ jet $E_T$
were evaluated.  
%
Estimated background rates and distributions in
$M^2_{\ell b}$ were varied as well.  The most important of these
effects is the uncertainty in the mean $Q^2$ used in the VECBOS simulation of
the $W$+jets background as discussed in Ref.~\cite{cdf_mass_prd}.
%
A set of CTEQ~\cite{cteq} and MRST~\cite{MRST} Parton Distribution Functions (PDFs)
were compared to the standard PDF set of MRST h-g and found to cause a
small spread in the measured $f_{V+A}$.
%
Systematic uncertainty due to the limited size of the Monte
Carlo simulation samples is also included.

%











prl_new.tex
%\documentclass[prl,twocolumn,showpacs,preprintnumbers,amsmath,amssymb]{revtex4}
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%\usepackage{dcolumn}% Align table columns on decimal point
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%\documentclass[preprint,showpacs,preprintnumbers,amsmath,amssymb]{revtex4}

% from Flor
%\documentclass[preprint,showpacs,preprintnumbers,amsmath,amssymb]{revtex4}

%\documentclass[preprint,showpacs,preprintnumbers,amsmath,amssymb,superscriptaddress]{revtex4}
\documentclass[prl,twocolumn,showpacs,preprintnumbers,amsmath,amssymb,superscriptaddress]{revtex4}
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%\def\MET {\not\!E_T}
\newcommand{\MET}{\mbox{$\protect \raisebox{.3ex}{$\not$}\!E_T$}}
\newcommand{\rmt}{\rm\textstyle}
\font\eightit=cmti8
\def\r#1{\ignorespaces $^{#1}$}

\begin{document}
\pagenumbering{arabic}

\preprint{APS/123-TOP}

\title{Measurement of the $W$ Boson Polarization in Top Decay \\ at CDF at $\sqrt{s}$ = 1.8 TeV}

\normalsize    

%\input{author}
\input{cdf_auth}

\date{\today}

\input{abstract}

\pacs{14.65.Ha, 12.15.Ji, 12.60.Cn, 13.88.+e \hspace{2cm} FERMILAB-PUB-04-353} 

\maketitle

\input{introduction}

\input{data}

\input{method}

\input{results}

\input{ack}

\begin{thebibliography}{9}

%\cite{Hill:1991at}
\bibitem{hill}
C.~T.~Hill,
%``Topcolor: Top quark condensation in a gauge extension of the standard model,''
Phys.\ Lett.\ B {\bf 266}, 419 (1991).
%%CITATION = PHLTA,B266,419;%%

% Ones that mention nonstandard interactions:
%\cite{Peccei:kr}
\bibitem{Peccei:kr}
R.~D.~Peccei and X.~Zhang,
%``Dynamical Symmetry Breaking And Universality Breakdown,''
Nucl.\ Phys.\ B {\bf 337}, 269 (1990).
%%CITATION = NUPHA,B337,269;%%
%We argue that, if the symmetry breakdown in the electroweak theory is dynamical, one should expect, in general, to have some nonuniversal interactions. Given the present bounds on flavor mixing, this imposes rather strong restrictions on the dynamics and the pattern of spontaneous symmetry breaking. The relevance of these considerations for top quark interactions is speculated upon. 

%\cite{Kane:1991bg}
\bibitem{Kane:1991bg}
G.~L.~Kane, G.~A.~Ladinsky and C.~P.~Yuan,
%``Using the top quark for testing standard model polarization and CP predictions,''
Phys.\ Rev.\ D {\bf 45}, 124 (1992).
%%CITATION = PHRVA,D45,124;%%


%\cite{Jezabek:1994zv}
\bibitem{Jezabek:1994zv}
M.~Jezabek and J.~H.~Kuhn,
%``V-A tests through leptons from polarized top quarks,''
Phys.\ Lett.\ B {\bf 329}, 317 (1994)
%[arXiv:hep-ph/9403366].
%%CITATION = HEP-PH 9403366;%%

%\cite{Nelson:1997xd}
\bibitem{Nelson:1997xd}
C.~A.~Nelson, B.~T.~Kress, M.~Lopes and T.~P.~McCauley,
%``General tests for t $\to$ W+ b couplings at hadron colliders,''
Phys.\ Rev.\ D {\bf 56}, 5928 (1997).
%%[arXiv:hep-ph/9707211].
%%CITATION = HEP-PH 9707211;%%





%\bibitem{F0} R. Peccei and X. Zhang, Nuc. Phys. B {\bf 337}, 269, 1990; G. Kane, C.P. Yuan, and D. Ladinsky, Phys. Rev. D {\bf 45}, 1531 (1992); M. Jezabek and J.H. Kuhn, Phys. Lett. B {\bf 329}, 317 (1994); C. A. Nelson, B. T. Kress, M. Lopes, and T.McCauley, Phys. Rev. D {\bf 56}, 5928 (1997). 

\bibitem{review}
For a review of V+A theories, see  T.~D.~Lee and C.~N.~Yang,
%``Question Of Parity Conservation In Weak Interactions,''
Phys.\ Rev.\  {\bf 104}, 254 (1956), J.~C.~Pati and A.~Salam,
%``Lepton Number As The Fourth Color,''
Phys.\ Rev.\ D {\bf 10}, 275 (1974), 
J.~Maalampi and M.~Roos,
%``Physics Of Mirror Fermions,''
Phys.\ Rept.\  {\bf 186}, 53 (1990),
R.~Foot,
%``An alternative SU(4) x SU(2)L x SU(2)R model,''
Phys.\ Lett.\ B {\bf 420}, 333 (1998),
S.~h.~Nam,
%``B anti-B mixing and CP violation in SU(2)L x SU(2)R x U(1) models,''
Phys.\ Rev.\ D {\bf 66}, 055008 (2002),
Q.~Shafi and Z.~Tavartkiladze,
%``SU(4)c X SU(2)L X SU(2)R model from 5D supersymmetric SU(4)c X SU(4)L+R,''
Phys.\ Rev.\ D {\bf 66}, 115002 (2002),
H.~S.~Goh, R.~N.~Mohapatra and S.~P.~Ng,
%``Minimal SUSY SO(10), b tau unification and large neutrino mixings,''
Phys.\ Lett.\ B {\bf 570}, 215 (2003).

\bibitem{triant}
Specifically, G.~Triantaphyllou,
%``New physics with mirror particles,''
J.\ Phys.\ G {\bf 26}, 99 (2000),
M.~Lindner and G.~Triantaphyllou,
%``Mirror families in electro-weak symmetry breaking,''
Phys.\ Lett.\ B {\bf 430}, 303 (1998).

% %\cite{Triantaphyllou:1998ke}
% \bibitem{triant}
% G.~Triantaphyllou,
% %``New physics with mirror particles,''
% J.\ Phys.\ G {\bf 26}, 99 (2000).
% %%[arXiv:hep-ph/9811250].
% %%CITATION = HEP-PH 9811250;%%

% %\cite{Lindner:1998er}
% \bibitem{Lindner:1998er}
% M.~Lindner and G.~Triantaphyllou,
% %``Mirror families in electro-weak symmetry breaking,''
% Phys.\ Lett.\ B {\bf 430}, 303 (1998)
%% [arXiv:hep-ph/9803383].
% %%CITATION = HEP-PH 9803383;%%

% % Lee and Yang's original parity violation paper :
% %\cite{Lee:1956qn}
% \bibitem{Lee:1956qn}
% T.~D.~Lee and C.~N.~Yang,
% %``Question Of Parity Conservation In Weak Interactions,''
% Phys.\ Rev.\  {\bf 104}, 254 (1956).
% %%CITATION = PHRVA,104,254;%%

% % TOPCITE 1000 ! :  (mentions V+A)
% %  must be mentioned !
% % mentions SU(2)_L X SU(2)_R X SU(4)
% %\cite{Pati:1974yy}
% \bibitem{Pati:1974yy}
% J.~C.~Pati and A.~Salam,
% %``Lepton Number As The Fourth Color,''
% Phys.\ Rev.\ D {\bf 10}, 275 (1974).
% %%CITATION = PHRVA,D10,275;%%

% %This reference is a slightly different SU(2)_L X SU(2)_R theory
% %with SU(4)_C
% %It seems like there are many models with these 2 groups plus
% %something else - this one references the above paper
% %\cite{Shafi:2002ck}
% \bibitem{Shafi:2002ck}
% Q.~Shafi and Z.~Tavartkiladze,
% %``SU(4)c X SU(2)L X SU(2)R model from 5D supersymmetric SU(4)c X SU(4)L+R,''
% Phys.\ Rev.\ D {\bf 66}, 115002 (2002),
% %%CITATION = PHRVA,D66,115002;%%

% % Another model
% %\cite{Foot:1997pb}
% \bibitem{Foot:1997pb}
% R.~Foot,
% %``An alternative SU(4) x SU(2)L x SU(2)R model,''
% Phys.\ Lett.\ B {\bf 420}, 333 (1998)
% %[arXiv:hep-ph/9708205].
%%CITATION = HEP-PH 9708205;%%


% % Here is another recent one with mention of SU(2)_L X SU(2)_R X U(1)
% %\cite{Nam:2002rq}
% \bibitem{Nam:2002rq}
% S.~h.~Nam,
% %``B anti-B mixing and CP violation in SU(2)L x SU(2)R x U(1) models,''
% Phys.\ Rev.\ D {\bf 66}, 055008 (2002)
% [arXiv:hep-ph/0206037].
% %%CITATION = HEP-PH 0206037;%%

% % This guy wrote a good review which is in a book i can't see on the web
% % finally, can see it on KEK server, took a few tries
% %\cite{Goh:2003sy}
% \bibitem{Goh:2003sy}
% H.~S.~Goh, R.~N.~Mohapatra and S.~P.~Ng,
% %``Minimal SUSY SO(10), b tau unification and large neutrino mixings,''
% Phys.\ Lett.\ B {\bf 570}, 215 (2003)
% [arXiv:hep-ph/0303055].
% %%CITATION = HEP-PH 0303055;%%

% interesting review of all classes of models
% % doesn't say SU(2)_R specifically but talks
% % about V+A 
% %\cite{Maalampi:1988va}
% \bibitem{Maalampi:1988va}
% J.~Maalampi and M.~Roos,
% %``Physics Of Mirror Fermions,''
% Phys.\ Rept.\  {\bf 186}, 53 (1990).
% %%CITATION = PRPLC,186,53;%%

%\cite{Choudhury:2001hs}
\bibitem{Choudhury:2001hs}
D.~Choudhury, T.~M.~Tait and C.~E.~Wagner,
%``Beautiful mirrors and precision electroweak data,''
Phys.\ Rev.\ D {\bf 65}, 053002 (2002).
%[arXiv:hep-ph/0109097].
%%CITATION = HEP-PH 0109097;%%


\bibitem{cleo}
K.~Fujikawa and A.~Yamada,
%``Test of the chiral structure of the top - bottom charged current by the process b $\to$ s gamma,''
Phys.\ Rev.\ D {\bf 49}, 5890 (1994).

\bibitem{pdg_masses}
K. Hagiwara et al., Phys. Rev. D {\bf 66}, 010001 (2002) and 2003 
off-year partial update for the 2004 edition available on the PDG WWW pages (URL: http://pdg.lbl.gov/)

%%\cite{Azzi:2004rc}
%%\bibitem{Azzi:2004rc}
%\bibitem{new_combo}
%P.~Azzi {\it et al.}  [CDF Collaborattion],
%%``Combination of CDF and D0 results on the top-quark mass,''
%%arXiv:hep-ex/0404010.
%%%CITATION = HEP-EX 0404010;%%

\bibitem{Tim}
  {Private communication with T. Tait.}

\bibitem{CDF} F. Abe {\em et al.}, Nucl. Instr. Meth. Phys. Res. A {\bf 271},
387 (1988); D. Amidei {\em et al., ibid.} {\bf 350}, 73 (1994); P. Azzi  {\em et al., ibid.} {\bf 360}, 137 (1995).

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{toplj}
F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass,''
% lepton + jets 
Phys.\ Rev.\ Lett.\  {\bf 80}, 2767 (1998).
%[arXiv:hep-ex/9801014].
%%CITATION = HEP-EX 9801014;%%

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{topdi}
F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass and t anti-t production cross section  from dilepton events at the Collider Detector at Fermilab,''
% reference dilepton emu purity
Phys.\ Rev.\ Lett.\  {\bf 80}, 2779 (1998).
%[arXiv:hep-ex/9802017].
%%CITATION = HEP-EX 9802017;%%

%\cite{eta}
\bibitem{eta}
In the CDF coordinate system, $\theta$ and $\phi$ are the polar and azimuthal
angles, respectively, with respect to the proton beam direction which defines
the z axis.  The pseudorapidity $\eta$ is defined as $- \ln{\tan \frac{\theta}{2}}$.   

\bibitem{VECBOS}
% %\cite{Berends:1990ax}
% %\bibitem{Berends:1990ax}
F.~A.~Berends, H.~Kuijf, B.~Tausk and W.~T.~Giele,
%``On The Production Of A W And Jets At Hadron Colliders,''
Nucl.\ Phys.\ B {\bf 357}, 32 (1991).
%%CITATION = NUPHA,B357,32;%%

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{oldtopresults}
F.~Abe {\it et al.}  [CDF Collaboration],
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Observation of top quark production in anti-p p collisions,''
% has b tag algorithm
Phys.\ Rev.\ Lett.\ {\bf 74}, 2626 (1995).
%[arXiv:hep-ex/9503002].
%%CITATION = HEP-EX 9802017;%%

%\cite{cdf_mass_prd}
\bibitem{cdf_mass_prd}
T.~Affolder {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass with the Collider Detector at  Fermilab,''
Phys.\ Rev.\ D {\bf 63}, 032003 (2001).
%%[arXiv:hep-ex/0006028].
%%CITATION = HEP-EX 0006028;%%

%\cite{Corcella:2000bw}
\bibitem{herwig}
G.~Corcella {\it et al.},
%``HERWIG 6: An event generator for hadron emission reactions with  interfering gluons (including supersymmetric processes),''
JHEP {\bf 0101}, 010 (2001). Both $t\bar{t}$ samples were generated
with HERWIG, the V+A sample using a custom version with adjustable $W$ helicity amplitudes.
%[arXiv:hep-ph/0011363].
%%CITATION = HEP-PH 0011363;%%

\bibitem{MRST} 
%\cite{Martin:1998sq}
A.~D.~Martin, R.~G.~Roberts, W.~J.~Stirling and R.~S.~Thorne,
%``Parton distributions: A new global analysis,''
Eur.\ Phys.\ J.\ C {\bf 4}, 463 (1998).
%[arXiv:hep-ph/9803445].
%%CITATION = HEP-PH 9803445;%%

%\cite{Demortier:1999vv}
%\bibitem{Demortier:1999vv}
\bibitem{combination}
L.~Demortier, R.~Hall, R.~Hughes, B.~Klima, R.~Roser and M.~Strovink  [The
                  Top Averaging Group Collaboration],
%``Combining the top quark mass results for run 1 from CDF and D0,''
FERMILAB-TM-2084.
%\href{http://www.slac.stanford.edu/spires/find/hep/www?r=fermilab-tm-2084}{SPIRES entry}



%\cite{Lai:1999wy}
\bibitem{cteq}
%\bibitem{Lai:1999wy}
H.~L.~Lai {\it et al.}  [CTEQ Collaboration],
%``Global {QCD} analysis of parton structure of the nucleon: CTEQ5 parton
%distributions,''
Eur.\ Phys.\ J.\ C {\bf 12}, 375 (2000).
%[arXiv:hep-ph/9903282].
%%CITATION = HEP-PH 9903282;%%

\bibitem{neyman}
J.~Neyman, Phil.\ Trans.\ Royal \ Soc.\ London, Series A, {\bf 236}, 333
(1937).

%\cite{Affolder:1999mp}
\bibitem{lpt}
%\bibitem{Affolder:1999mp}
T.~Affolder {\it et al.}  [CDF Collaboration],
%``Measurement of the helicity of W bosons in top quark decays,''
Phys.\ Rev.\ Lett.\  {\bf 84}, 216 (2000).
%[arXiv:hep-ex/9909042].
%%CITATION = HEP-EX 9909042;%%


%\cite{Abe:1997vq}
%\bibitem{Abe:1997vq}
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass,''
% lepton + jets 
%Phys.\ Rev.\ Lett.\  {\bf 80}, 2767 (1998).
%[arXiv:hep-ex/9801014].
%%CITATION = HEP-EX 9801014;%%

%\cite{Abe:1995hr}
%\bibitem{Abe:1995hr}
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Observation of top quark production in anti-p p collisions,''
% has b tag algorithm
%Phys.\ Rev.\ Lett.\  {\bf 74}, 2626 (1995).
%[arXiv:hep-ex/9503002].
%%CITATION = HEP-EX 9503002;%%



\end{thebibliography}

 
\end{document}







results.tex
%auto-ignore
%\section{Results and Conclusions}

%\begin{figure}
%\resizebox{0.85\columnwidth}{0.85\height}{\includegraphics{dilepton_result_and_data}\vspace*{1cm}}
%\resizebox{0.4\columnwidth}{0.3\height}{\includegraphics{march_dilepton_result}}
%\resizebox{60mm}{!}{\includegraphics{march_dilepton_result}}
%\resizebox{60mm}{!}{\includegraphics{march_svx2_result}}
%\resizebox{60mm}{!}{\includegraphics{march_svx1_result}}
%\resizebox{60mm}{!}{\includegraphics{march_combined_likelihood}}
%\caption{Data and Monte Carlo distributions for dilepton sample with fit value of $f_{V+A}$ }
%\label{fig:dilepton_result}
%\end{figure}


% figure* environment sets it across the top of a page in two column
\begin{figure*}
%\psfig{file=march_dilepton_result,width=0.9\textwidth}
%\psfig{file=march_svx2_result,width=0.9\textwidth}
%\psfig{file=march_svx1_result,width=0.9\textwidth}
%\psfig{file=march_combined_likelihood,width=0.9\textwidth}
  \resizebox{0.3\textwidth}{!}{\includegraphics{draft2_result_dilepton}}
  \resizebox{0.3\textwidth}{!}{\includegraphics{draft2_result_svx2}}
  \resizebox{0.3\textwidth}{!}{\includegraphics{draft2_result_svx1}}
\caption{Data and Standard Model Monte Carlo distributions for each
sample. The last bin 
includes combinations greater than 30,000 $GeV^2$, which are predominantly
the result of incorrect pairings. Errors are statistical only.}
\label{fig:results}
\end{figure*}

\begin{figure}
%\resizebox{0.9\columnwidth}{!}{\includegraphics{march_combined_likelihood}}
\resizebox{0.9\columnwidth}{!}{\includegraphics{combined_result_v3}}
\caption{$-2\log{\cal L}$ as a function of $f_{V+A}$ for all samples
and for the combined likelihood fit.  The result for the dilepton sample 
is $f_{V+A}$ = 0.08$^{+0.74}_{-.0.42}$, for the single-tagged sample is
$f_{V+A}$ = -1.91$^{+0.69}_{-.0.48}$, and for the double-tagged sample is
$f_{V+A}$ = 0.63$^{+2.62}_{-2.11}$.  Errors are statistical only.}
\label{fig:combined_results}
\end{figure}

The data and expected Standard Model distributions are shown for each of the
three samples in Fig.~\ref{fig:results}.  We can combine
the statistical likelihood as a function of $f_{V+A}$ for each sample into
the joint likelihood shown in Fig.~\ref{fig:combined_results}.  The combined
result for $f_{V+A}$ and its $1\sigma$ uncertainties are 
\begin{equation}
f_{V+A} =
-0.21_{-0.24}^{+0.42}({\rmt stat.\,})\pm0.21({\rmt syst.\,})
\end{equation}

The central value depends on the true top mass, $f_{V+A} (M_t) = -0.21 +
0.037 (M_t - 174.3$ GeV), and the top mass uncertainty is reflected in the
systematic error.  This central value lies in an unphysical region, but is
more consistent with a Standard Model V$-$A interaction for the $tbW$ vertex
than a V$+$A interaction.  We can place a one-sided upper limit on the
fraction of rate due to a V$+$A component by construction of a Neyman
confidence band in the variable $f_{V+A}$ ~\cite{neyman}. This procedure
results in an upper limit on $f_{V+A}$ of $0.80$ at 95\% confidence level.
With the assumption of a standard model longitudinal helicity fraction, this
corresponds to $f_{+} < 0.24$ at 95\% confidence level.

$W$ polarization in top decays has also been studied at CDF in the same data
sample using the lepton $P_T$ \cite{lpt} as the observable to discriminate
between left-handed and right-handed $W$ bosons, under the assumption of a
fixed longitudinal helicity.  These two results have different selection
criteria, but share largely overlapping data sets.  In addition, the
observables themselves are weakly correlated, and a large fraction of the
systematic uncertainties are common.  Nevertheless, the overall statistical
correlation of the two results is only about $0.4$.  Under the simplifying
assumption of Gaussian uncertainties, the combined measurement using both the
$M_{\ell b}$ and lepton $P_T$ approaches is that the fraction of $W$
bosons produced in a V$+$A interaction is
\begin{equation}
f_{V+A}=-0.07\pm0.37({\rmt stat.\, \oplus syst.\,}).
\end{equation}
The combined upper limit is $f_{V+A} < 0.61$ at 95\% confidence level.  In
terms of the right-handed helicity fraction, this corresponds to $f_{+} <
0.18$ at 95\% confidence level.  The combined result is inconsistent with a
pure V$+$A theory at a confidence level equivalent to the probability of a
$2.7\sigma$ Gaussian statistical fluctation.

In conclusion, we have used the measurement of $M_{\ell b}$ in $t\bar{t}$
events to measure the polarization of $W$ bosons in top decay.  The results
are consistent with the V$-$A theory of the weak interaction.  The data are
used to set a limit on the fraction of top 
%a possible admixture of 
decays mediated by a V$+$A interaction.
This is the first result providing significant direct evidence against a pure
V+A theory of weak interactions in top decay;
it also provides the first significant limits on partial admixtures of a
V$+$A interaction with the expected V$-$A reaction.  
%These measurements are
%shown to be statistically limited, and therefore significant improvements are
%expected in the near future from Run II of the Tevatron.













hep-ex0411070.extracted_bib
\begin{thebibliography}{9}

%\cite{Hill:1991at}
\bibitem{hill}
C.~T.~Hill,
%``Topcolor: Top quark condensation in a gauge extension of the standard model,''
Phys.\ Lett.\ B {\bf 266}, 419 (1991).
%%CITATION = PHLTA,B266,419;%%

% Ones that mention nonstandard interactions:
%\cite{Peccei:kr}
\bibitem{Peccei:kr}
R.~D.~Peccei and X.~Zhang,
%``Dynamical Symmetry Breaking And Universality Breakdown,''
Nucl.\ Phys.\ B {\bf 337}, 269 (1990).
%%CITATION = NUPHA,B337,269;%%
%We argue that, if the symmetry breakdown in the electroweak theory is dynamical, one should expect, in general, to have some nonuniversal interactions. Given the present bounds on flavor mixing, this imposes rather strong restrictions on the dynamics and the pattern of spontaneous symmetry breaking. The relevance of these considerations for top quark interactions is speculated upon. 

%\cite{Kane:1991bg}
\bibitem{Kane:1991bg}
G.~L.~Kane, G.~A.~Ladinsky and C.~P.~Yuan,
%``Using the top quark for testing standard model polarization and CP predictions,''
Phys.\ Rev.\ D {\bf 45}, 124 (1992).
%%CITATION = PHRVA,D45,124;%%


%\cite{Jezabek:1994zv}
\bibitem{Jezabek:1994zv}
M.~Jezabek and J.~H.~Kuhn,
%``V-A tests through leptons from polarized top quarks,''
Phys.\ Lett.\ B {\bf 329}, 317 (1994)
%[arXiv:hep-ph/9403366].
%%CITATION = HEP-PH 9403366;%%

%\cite{Nelson:1997xd}
\bibitem{Nelson:1997xd}
C.~A.~Nelson, B.~T.~Kress, M.~Lopes and T.~P.~McCauley,
%``General tests for t $\to$ W+ b couplings at hadron colliders,''
Phys.\ Rev.\ D {\bf 56}, 5928 (1997).
%%[arXiv:hep-ph/9707211].
%%CITATION = HEP-PH 9707211;%%





%\bibitem{F0} R. Peccei and X. Zhang, Nuc. Phys. B {\bf 337}, 269, 1990; G. Kane, C.P. Yuan, and D. Ladinsky, Phys. Rev. D {\bf 45}, 1531 (1992); M. Jezabek and J.H. Kuhn, Phys. Lett. B {\bf 329}, 317 (1994); C. A. Nelson, B. T. Kress, M. Lopes, and T.McCauley, Phys. Rev. D {\bf 56}, 5928 (1997). 

\bibitem{review}
For a review of V+A theories, see  T.~D.~Lee and C.~N.~Yang,
%``Question Of Parity Conservation In Weak Interactions,''
Phys.\ Rev.\  {\bf 104}, 254 (1956), J.~C.~Pati and A.~Salam,
%``Lepton Number As The Fourth Color,''
Phys.\ Rev.\ D {\bf 10}, 275 (1974), 
J.~Maalampi and M.~Roos,
%``Physics Of Mirror Fermions,''
Phys.\ Rept.\  {\bf 186}, 53 (1990),
R.~Foot,
%``An alternative SU(4) x SU(2)L x SU(2)R model,''
Phys.\ Lett.\ B {\bf 420}, 333 (1998),
S.~h.~Nam,
%``B anti-B mixing and CP violation in SU(2)L x SU(2)R x U(1) models,''
Phys.\ Rev.\ D {\bf 66}, 055008 (2002),
Q.~Shafi and Z.~Tavartkiladze,
%``SU(4)c X SU(2)L X SU(2)R model from 5D supersymmetric SU(4)c X SU(4)L+R,''
Phys.\ Rev.\ D {\bf 66}, 115002 (2002),
H.~S.~Goh, R.~N.~Mohapatra and S.~P.~Ng,
%``Minimal SUSY SO(10), b tau unification and large neutrino mixings,''
Phys.\ Lett.\ B {\bf 570}, 215 (2003).

\bibitem{triant}
Specifically, G.~Triantaphyllou,
%``New physics with mirror particles,''
J.\ Phys.\ G {\bf 26}, 99 (2000),
M.~Lindner and G.~Triantaphyllou,
%``Mirror families in electro-weak symmetry breaking,''
Phys.\ Lett.\ B {\bf 430}, 303 (1998).

% %\cite{Triantaphyllou:1998ke}
% \bibitem{triant}
% G.~Triantaphyllou,
% %``New physics with mirror particles,''
% J.\ Phys.\ G {\bf 26}, 99 (2000).
% %%[arXiv:hep-ph/9811250].
% %%CITATION = HEP-PH 9811250;%%

% %\cite{Lindner:1998er}
% \bibitem{Lindner:1998er}
% M.~Lindner and G.~Triantaphyllou,
% %``Mirror families in electro-weak symmetry breaking,''
% Phys.\ Lett.\ B {\bf 430}, 303 (1998)
%% [arXiv:hep-ph/9803383].
% %%CITATION = HEP-PH 9803383;%%

% % Lee and Yang's original parity violation paper :
% %\cite{Lee:1956qn}
% \bibitem{Lee:1956qn}
% T.~D.~Lee and C.~N.~Yang,
% %``Question Of Parity Conservation In Weak Interactions,''
% Phys.\ Rev.\  {\bf 104}, 254 (1956).
% %%CITATION = PHRVA,104,254;%%

% % TOPCITE 1000 ! :  (mentions V+A)
% %  must be mentioned !
% % mentions SU(2)_L X SU(2)_R X SU(4)
% %\cite{Pati:1974yy}
% \bibitem{Pati:1974yy}
% J.~C.~Pati and A.~Salam,
% %``Lepton Number As The Fourth Color,''
% Phys.\ Rev.\ D {\bf 10}, 275 (1974).
% %%CITATION = PHRVA,D10,275;%%

% %This reference is a slightly different SU(2)_L X SU(2)_R theory
% %with SU(4)_C
% %It seems like there are many models with these 2 groups plus
% %something else - this one references the above paper
% %\cite{Shafi:2002ck}
% \bibitem{Shafi:2002ck}
% Q.~Shafi and Z.~Tavartkiladze,
% %``SU(4)c X SU(2)L X SU(2)R model from 5D supersymmetric SU(4)c X SU(4)L+R,''
% Phys.\ Rev.\ D {\bf 66}, 115002 (2002),
% %%CITATION = PHRVA,D66,115002;%%

% % Another model
% %\cite{Foot:1997pb}
% \bibitem{Foot:1997pb}
% R.~Foot,
% %``An alternative SU(4) x SU(2)L x SU(2)R model,''
% Phys.\ Lett.\ B {\bf 420}, 333 (1998)
% %[arXiv:hep-ph/9708205].
%%CITATION = HEP-PH 9708205;%%


% % Here is another recent one with mention of SU(2)_L X SU(2)_R X U(1)
% %\cite{Nam:2002rq}
% \bibitem{Nam:2002rq}
% S.~h.~Nam,
% %``B anti-B mixing and CP violation in SU(2)L x SU(2)R x U(1) models,''
% Phys.\ Rev.\ D {\bf 66}, 055008 (2002)
% [arXiv:hep-ph/0206037].
% %%CITATION = HEP-PH 0206037;%%

% % This guy wrote a good review which is in a book i can't see on the web
% % finally, can see it on KEK server, took a few tries
% %\cite{Goh:2003sy}
% \bibitem{Goh:2003sy}
% H.~S.~Goh, R.~N.~Mohapatra and S.~P.~Ng,
% %``Minimal SUSY SO(10), b tau unification and large neutrino mixings,''
% Phys.\ Lett.\ B {\bf 570}, 215 (2003)
% [arXiv:hep-ph/0303055].
% %%CITATION = HEP-PH 0303055;%%

% interesting review of all classes of models
% % doesn't say SU(2)_R specifically but talks
% % about V+A 
% %\cite{Maalampi:1988va}
% \bibitem{Maalampi:1988va}
% J.~Maalampi and M.~Roos,
% %``Physics Of Mirror Fermions,''
% Phys.\ Rept.\  {\bf 186}, 53 (1990).
% %%CITATION = PRPLC,186,53;%%

%\cite{Choudhury:2001hs}
\bibitem{Choudhury:2001hs}
D.~Choudhury, T.~M.~Tait and C.~E.~Wagner,
%``Beautiful mirrors and precision electroweak data,''
Phys.\ Rev.\ D {\bf 65}, 053002 (2002).
%[arXiv:hep-ph/0109097].
%%CITATION = HEP-PH 0109097;%%


\bibitem{cleo}
K.~Fujikawa and A.~Yamada,
%``Test of the chiral structure of the top - bottom charged current by the process b $\to$ s gamma,''
Phys.\ Rev.\ D {\bf 49}, 5890 (1994).

\bibitem{pdg_masses}
K. Hagiwara et al., Phys. Rev. D {\bf 66}, 010001 (2002) and 2003 
off-year partial update for the 2004 edition available on the PDG WWW pages (URL: http://pdg.lbl.gov/)

%%\cite{Azzi:2004rc}
%%\bibitem{Azzi:2004rc}
%\bibitem{new_combo}
%P.~Azzi {\it et al.}  [CDF Collaborattion],
%%``Combination of CDF and D0 results on the top-quark mass,''
%%arXiv:hep-ex/0404010.
%%%CITATION = HEP-EX 0404010;%%

\bibitem{Tim}
  {Private communication with T. Tait.}

\bibitem{CDF} F. Abe {\em et al.}, Nucl. Instr. Meth. Phys. Res. A {\bf 271},
387 (1988); D. Amidei {\em et al., ibid.} {\bf 350}, 73 (1994); P. Azzi  {\em et al., ibid.} {\bf 360}, 137 (1995).

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{toplj}
F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass,''
% lepton + jets 
Phys.\ Rev.\ Lett.\  {\bf 80}, 2767 (1998).
%[arXiv:hep-ex/9801014].
%%CITATION = HEP-EX 9801014;%%

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{topdi}
F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass and t anti-t production cross section  from dilepton events at the Collider Detector at Fermilab,''
% reference dilepton emu purity
Phys.\ Rev.\ Lett.\  {\bf 80}, 2779 (1998).
%[arXiv:hep-ex/9802017].
%%CITATION = HEP-EX 9802017;%%

%\cite{eta}
\bibitem{eta}
In the CDF coordinate system, $\theta$ and $\phi$ are the polar and azimuthal
angles, respectively, with respect to the proton beam direction which defines
the z axis.  The pseudorapidity $\eta$ is defined as $- \ln{\tan \frac{\theta}{2}}$.   

\bibitem{VECBOS}
% %\cite{Berends:1990ax}
% %\bibitem{Berends:1990ax}
F.~A.~Berends, H.~Kuijf, B.~Tausk and W.~T.~Giele,
%``On The Production Of A W And Jets At Hadron Colliders,''
Nucl.\ Phys.\ B {\bf 357}, 32 (1991).
%%CITATION = NUPHA,B357,32;%%

%\cite{Abe:1997iz}
%\bibitem{Abe:1997iz}
\bibitem{oldtopresults}
F.~Abe {\it et al.}  [CDF Collaboration],
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Observation of top quark production in anti-p p collisions,''
% has b tag algorithm
Phys.\ Rev.\ Lett.\ {\bf 74}, 2626 (1995).
%[arXiv:hep-ex/9503002].
%%CITATION = HEP-EX 9802017;%%

%\cite{cdf_mass_prd}
\bibitem{cdf_mass_prd}
T.~Affolder {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass with the Collider Detector at  Fermilab,''
Phys.\ Rev.\ D {\bf 63}, 032003 (2001).
%%[arXiv:hep-ex/0006028].
%%CITATION = HEP-EX 0006028;%%

%\cite{Corcella:2000bw}
\bibitem{herwig}
G.~Corcella {\it et al.},
%``HERWIG 6: An event generator for hadron emission reactions with  interfering gluons (including supersymmetric processes),''
JHEP {\bf 0101}, 010 (2001). Both $t\bar{t}$ samples were generated
with HERWIG, the V+A sample using a custom version with adjustable $W$ helicity amplitudes.
%[arXiv:hep-ph/0011363].
%%CITATION = HEP-PH 0011363;%%

\bibitem{MRST} 
%\cite{Martin:1998sq}
A.~D.~Martin, R.~G.~Roberts, W.~J.~Stirling and R.~S.~Thorne,
%``Parton distributions: A new global analysis,''
Eur.\ Phys.\ J.\ C {\bf 4}, 463 (1998).
%[arXiv:hep-ph/9803445].
%%CITATION = HEP-PH 9803445;%%

%\cite{Demortier:1999vv}
%\bibitem{Demortier:1999vv}
\bibitem{combination}
L.~Demortier, R.~Hall, R.~Hughes, B.~Klima, R.~Roser and M.~Strovink  [The
                  Top Averaging Group Collaboration],
%``Combining the top quark mass results for run 1 from CDF and D0,''
FERMILAB-TM-2084.
%\href{http://www.slac.stanford.edu/spires/find/hep/www?r=fermilab-tm-2084}{SPIRES entry}



%\cite{Lai:1999wy}
\bibitem{cteq}
%\bibitem{Lai:1999wy}
H.~L.~Lai {\it et al.}  [CTEQ Collaboration],
%``Global {QCD} analysis of parton structure of the nucleon: CTEQ5 parton
%distributions,''
Eur.\ Phys.\ J.\ C {\bf 12}, 375 (2000).
%[arXiv:hep-ph/9903282].
%%CITATION = HEP-PH 9903282;%%

\bibitem{neyman}
J.~Neyman, Phil.\ Trans.\ Royal \ Soc.\ London, Series A, {\bf 236}, 333
(1937).

%\cite{Affolder:1999mp}
\bibitem{lpt}
%\bibitem{Affolder:1999mp}
T.~Affolder {\it et al.}  [CDF Collaboration],
%``Measurement of the helicity of W bosons in top quark decays,''
Phys.\ Rev.\ Lett.\  {\bf 84}, 216 (2000).
%[arXiv:hep-ex/9909042].
%%CITATION = HEP-EX 9909042;%%


%\cite{Abe:1997vq}
%\bibitem{Abe:1997vq}
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Measurement of the top quark mass,''
% lepton + jets 
%Phys.\ Rev.\ Lett.\  {\bf 80}, 2767 (1998).
%[arXiv:hep-ex/9801014].
%%CITATION = HEP-EX 9801014;%%

%\cite{Abe:1995hr}
%\bibitem{Abe:1995hr}
%F.~Abe {\it et al.}  [CDF Collaboration],
%``Observation of top quark production in anti-p p collisions,''
% has b tag algorithm
%Phys.\ Rev.\ Lett.\  {\bf 74}, 2626 (1995).
%[arXiv:hep-ex/9503002].
%%CITATION = HEP-EX 9503002;%%



\end{thebibliography}