First Observation of a New Narrow \dsj\ Meson at 2632 \mvc
Peter S. Cooper
{\em Fermi National Accelerator Laboratory}
(For the Selex Collaboration) \thanks{http://www-selex.fnal.gov/}
We report the first observation of a charm-strange meson $\dsj(2632)$ at a mass of $\MassA \pm \sMassA\ \mvc$ in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, \dseta and \dzk. In the ${D_{s}^{+} \eta}$ decay mode we observe a peak with \Nevt events over a combinatoric background of \Back events at a mass of \Mass $\pm$ \sMass \mvC. There is a corresponding peak of \Nevtb events over a background of \Backb at \Massb $\pm$ \sMassb \mvc in the decay mode \dzk. The relative branching ratio $\Gamma(\dzk)/\Gamma(\dseta)$ is \Br \ $\pm$ \dBr. The full vesion of this paper has been accepted for publication in PRL~\cite{Evdokimov:2004iy}. Here I have reproduced only the mass difference signal plots for the \dseta and \dzk decay modes.
pcooper-pic04.tex
\documentclass[12pt]{article}
\usepackage{pic04}
\usepackage{hyperref}
\usepackage{url}
\usepackage{graphicx}

\def\fsec    {fs}                               % define how to write fsec
\def\MeV     {{\mbox{$\mathrm{MeV}$}}}
\def\mvC     {{\mbox{$\mathrm{MeV/c^2}$}}}
\def\mvc     {{\mbox{$\mvC \ $}}}
\def\GeV     {{\mbox{$\mathrm{GeV}$}}}
\def\gvc     {{\mbox{$\mathrm{GeV/c} \ $}}}
\def\dsj     {{\mbox{$\mathrm{D^{+}_{sJ}}$}}}
\def\dsM     {{\mbox{$\rm{D_{s}}$}}}
\def\dsm     {{\mbox{$\dsM\ $}}}
\def\dss     {{\mbox{$\rm{D_{s}}^{*} \ $}}}
\def\dS      {{\mbox{$\rm{K}\rm{K}\pi^{\pm} $}}}
\def\ds      {{\mbox{$\dS \ $}}}
\def\dse     {{\mbox{$\dsj(2632) \rightarrow \rm{D_{s}^{+}} \eta \ $}}}
\def\dzk     {{\mbox{$\rm{D^{0} K^+} $}}}
\def\dseta   {{\mbox{$\rm{D_{s}^{+} \eta} \ $}}}


\def\Nevt    {101 }                             % events in signal region
\def\Back    {54.9 }                            % mixed background events
\def\Signf   {$6.2 \ \sigma$ }                  % Gaussian significance
\def\Nsig    {43.4 }                            % Fit signal
\def\dNsig   {9.1 }                             % Fit signal uncertainty
\def\DMass   {666.9 }                           % Fit Mass difference
\def\Mass    {2635.4 }                          % Fit Mass
\def\sMass   {3.3 }                             % Fit Mass uncertainty
\def\Res     {10.9 }                            % Fit Mass resolution
\def\Rchi    {1.10 }                            % Fit Rchi2

\def\Nevtb   {21 }                              % events in signal region
\def\Backb   {6.9 }                             % Fit background events
\def\Signfb  {$5.3 \ \sigma$ }                  % Gaussian significance
\def\Nsigb   {13.2}                             % fit signal events
\def\dNsigb  { 4.9}                             % fit signal uncertainty
\def\DMassb  {767.0 }                           % Fit Mass difference
\def\Massb   {2631.5 }                          % Fit Mass
\def\sMassb  {2.0 }                             % Fit Mass uncertainty
\def\Widthb  {<17}                              % Width limit (90%CL)
\def\Resb    {4.9 }                             % MC Mass resolution

\def\MassA   {2632.5 }                          % Average Mass
\def\sMassA  {1.7 }                             % Average Mass uncertainty

\def\Br      {0.14}                             % relative branching ratio
\def\dBr     {0.06}                             % branching ratio uncertainty

\begin{document}

\title{\bf First Observation of a New Narrow \dsj\  Meson at 2632 \mvc}

\author{Peter S. Cooper\\
        {\em Fermi National Accelerator Laboratory}
        \\(For the Selex Collaboration)
        \thanks{http://www-selex.fnal.gov/}}
\maketitle

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% photograph of author
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%  uncomment the following lines.
%
%\begin{figure}[h]
%\begin{center}
%
% include photograph for proceeding version
%
%\includegraphics
%[height=4.5cm]{pcooper-headshot.eps}
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% insert a fixed vertical spacing instead for the ArXiv preprint
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\vspace{4.5cm}
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%\end{center}
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\baselineskip=14.5pt
\begin{abstract}
We report the first observation of a charm-strange meson 
$\dsj(2632)$ at a mass of $\MassA \pm \sMassA\ \mvc$ in data from SELEX, 
the charm hadro-production experiment E781 at Fermilab.  This state is seen in 
two decay modes, \dseta and \dzk.  In the $\rm{D_{s}^{+} \eta}$ decay mode 
we observe a peak with \Nevt events over a combinatoric background of \Back 
events at a mass of \Mass $\pm$ \sMass \mvC.  There is a corresponding peak of 
\Nevtb events over a background of \Backb at \Massb $\pm$ \sMassb \mvc in the 
decay mode \dzk.  The relative branching ratio $\Gamma(\dzk)/\Gamma(\dseta)$ 
is \Br \ $\pm$ \dBr.  The full vesion of this paper has been accepted for 
publication in PRL~\cite{Evdokimov:2004iy}.  Here I have reproduced only the 
mass difference signal plots for the \dseta and \dzk decay modes.
\end{abstract}
\newpage

\begin{figure}[ht]
\includegraphics[width=3.1in]{fig3}
%\caption{ M(\ds$^{\pm} \eta$) - M(\ds) mass difference distribution.  
%          The darker shaded region is the event excess used in the 
%          estimation of  signal significance. The lighter shaded region is 
%          the event-mixed combinatoric background described in the text.  
%          The inset shows the difference of the two with a Gaussian fit to 
%          the signal.}
\label{dseta}
\end{figure}

\begin{figure}[ht]
\includegraphics[width=3.1in]{fig4}
%\caption{(a) \dsm(2632) $\rightarrow \dzk$ mass difference 
%             distribution. 
%             Charged conjugates are included. 
%             The shaded regions are the event excesses used in the estimation 
%             of  signal significances. 
%        (b) Wrong sign background $\rm{D^0 \ K^{-}}$ events.}
\label{d0k}
\end{figure}

\begin{thebibliography}{9}
%\cite{Evdokimov:2004iy}
\bibitem{Evdokimov:2004iy}
A.~V.~Evdokimov  [SELEX Collaboration],
``First observation of a narrow charm-strange meson \dse and $D^{0} K{+}$,''
arXiv:hep-ex/0406045, Accepted for publication in PRL.
%%CITATION = HEP-EX 0406045;%%
\end{thebibliography}

\end{document}

hep-ex0411018.extracted_bib
\begin{thebibliography}{9}
%\cite{Evdokimov:2004iy}
\bibitem{Evdokimov:2004iy}
A.~V.~Evdokimov  [SELEX Collaboration],
``First observation of a narrow charm-strange meson \dse and $D^{0} K{+}$,''
arXiv:hep-ex/0406045, Accepted for publication in PRL.
%%CITATION = HEP-EX 0406045;%%
\end{thebibliography}