Anomalous Top-Higgs Couplings and Top Polarisation in Single Top and Higgs Associated Production at the LHC
Archil Kobakhidze\footnote{archilk@physics.usyd.edu.au
In this paper, we put constraints on anomalous $\mathcal{CP$-violating top-Higgs couplings using the currently available Higgs data and explore the prospect of measuring these couplings at 240 GeV TLEP. We find that the $\mathcal{CP$-violating phase $\xi$ is currently limited in the range $|\xi|< 0.6\pi$ at 95\% C.L. and may be further constrained to $|\xi| <0.07\pi$ at TLEP. Under this consideration, we further investigate the observability of the scalar ($\xi =0$), pseudoscalar ($\xi =0.5\pi$) and mixed ($\xi =0.25\pi$) top-Higgs interactions through the channel $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b)j$. We find that it is most promising to observe pure pseudoscalar interactions with $y_t=y_t^{SM$, although this will be challenging due to a low signal to background ratio. We also find that the anomalous top-Higgs couplings can lead to sizeable differences in lepton forward-backward asymmetries and can be distinguished by measuring the lepton angular distributions from polarised top quarks at 14 TeV LHC.
tophiggs.tex
\documentclass[preprint,preprintnumbers,amsmath,amssymb,nofootinbib]{revtex4}
\usepackage{bbm}
\usepackage{amsfonts}
\usepackage{booktabs}
\usepackage{mathrsfs}
\usepackage{epsfig}
\usepackage{graphicx}% Include figure files
\usepackage{dcolumn}% Align table columns on decimal point
\usepackage{bm}% bold math
\usepackage{amsmath}
\usepackage{slashed}
\usepackage{subfigure}
\usepackage{multirow}
\usepackage{color}

\let\jnfont=\rm
\def\NPB#1,{{\jnfont Nucl.\ Phys.\ B }{\bf #1},}
\def\PLB#1,{{\jnfont Phys.\ Lett.\ B }{\bf #1},}
\def\EPJC#1,{{\jnfont Eur.\ Phys.\ Jour.\ C }{\bf #1},}
\def\PRD#1,{{\jnfont Phys.\ Rev.\ D }{\bf #1},}
\def\PRL#1,{{\jnfont Phys.\ Rev.\ Lett.\ }{\bf #1},}
\def\MPLA#1,{{\jnfont Mod.\ Phys.\ Lett.\ A }{\bf #1},}
\def\JPG#1,{{\jnfont J.\ Phys.\ G}{\bf #1},}
\def\CTP#1,{{\jnfont Commun.\ Theor.\ Phys.\ }{\bf #1},}
\def\ZPC#1,{{\jnfont Z.\ Phys.\ C }{\bf #1},}
\def\JHEP#1,{{\jnfont JHEP \ }{\bf #1},}
\def\Rv{\not{\hbox{\kern-1pt $R$}}}
\def\p{\not{\hbox{\kern-3pt $p$}}}

\newcommand{\SLASH}[2]{\makebox[#2ex][l]{$#1$}/}

\begin{document}


\title{Anomalous Top-Higgs Couplings and Top Polarisation in Single Top and Higgs Associated Production at the LHC}% Force line breaks with \\
%%\thanks{A footnote to the article title}%

\author{Archil Kobakhidze\footnote{archilk@physics.usyd.edu.au}, Lei Wu\footnote{leiwu@physics.usyd.edu.au} and Jason Yue\footnote{j.yue@physics.usyd.edu.au}}
\affiliation{ ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006, Australia}%

\date{\today}% It is always \today, today,
             %  but any date may be explicitly specified

\begin{abstract}
In this paper, we put constraints on anomalous $\mathcal{CP}$-violating top-Higgs couplings using the currently available Higgs data and explore the prospect of measuring these couplings at 240 GeV TLEP. We find that the $\mathcal{CP}$-violating phase $\xi$ is currently limited in the range $|\xi|< 0.6\pi$ at 95\% C.L. and may be further constrained to $|\xi| <0.07\pi$ at TLEP. Under this consideration, we further investigate the observability of the scalar ($\xi =0$), pseudoscalar ($\xi =0.5\pi$) and mixed ($\xi =0.25\pi$)  top-Higgs interactions through the channel $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$. We find that it is most promising to observe pure pseudoscalar interactions with $y_t=y_t^{SM}$, although this will be challenging due to a low signal to background ratio. We also find that the anomalous top-Higgs couplings can lead to sizeable differences in lepton forward-backward asymmetries and can be distinguished by measuring the lepton angular distributions from polarised top quarks at 14 TeV LHC.
\end{abstract}

\maketitle

%\tableofcontents

\section{\label{sec:level1}Introduction}
The discovery of the Higgs boson at the Large Hadron Collider (LHC) \cite{higgs-atlas,higgs-cms} is a major step towards elucidating the electroweak symmetry breaking (EWSB) mechanism. To ultimately establish its nature, a precise measurement of the Higgs couplings to fermions and gauge bosons, and Higgs self-coupling is an important task of experiments at LHC and future colliders \cite{review,hf}. Although the observed Higgs signals are still plagued with large uncertainties, they have at least firmly established the key Higgs production and decay channels predicted by the Standard Model (SM). In turn, the Higgs main production channel $gg\rightarrow h$ indirectly indicates the existence of top-Higgs interactions.

In the SM, top quark is the heaviest fermion and hence has the strongest coupling to the Higgs boson. As such, it plays an important role in the EWSB and in various cosmological phenomena, such as electroweak phase transition and baryogenesis. The associated production of the top pair with Higgs boson have been widely investigated at the LHC \cite{tth_old,tth_new} as a direct probe of the top-Higgs Yukawa coupling. Based on an integrated luminosity of $L= 20.3$ fb$^{-1}$, the ATLAS collaboration has analysed $pp \to t\overline{t}h$, with $h\to b\overline{b}$, and set a $95\%$ C.L. limit \cite{atlas_tth} on the $t\overline{t}h$ cross section, $\sigma_{t\overline{t}h}<4.1\sigma^{SM}_{t\overline{t}h}$. The determination of the dominant background, $t\overline{t}\ +$ jets, is expected to be improved by the copious production of top quarks at the LHC \cite{ttj}. However, even if the $t\overline{t}h$ coupling can be measured with sufficient accuracy, information on the relative phase between the top-Higgs Yukawa coupling and gauge-Higgs coupling will still be lacking.

In this regard, the search for Higgs boson production in association with a single top have proposed in Refs.~\cite{thj_old}. Like single top productions, there are three different production modes characterised by the virtuality of the $W$ boson \cite{maltoni_thj1}. The $t$ channel process $pp \to thj$ with a space-like $W$ has the largest cross section amongst these production mode, reaching $\sim88.2$ fb (14 TeV) at NLO QCD in the SM \cite{maltoni_thj2}. The most important feature of $thj$ production is that the interference between the contributing processes with $ht\overline{t}$ and $hWW$ couplings allows direct examination both the modulus ($y_t$) and the $\mathcal{CP}$ violating phase ($\xi$) of the top-Higgs Yukawa coupling \cite{maltoni_thj1,maltoni_thj2,biswas_thj,ellis_thj,englert,lee_thj}. Such anomalous top-Higgs couplings may result from various new physics models \cite{eff,cpv_model1,cpv_model2,cpv_model3,cpv_model4,archil}. The CMS collaboration has very recently presented the result on $thj$ searches in the $h \to \gamma\gamma$ channel, and obtained a weak bound on the cross section of events with inverted top-Higgs coupling \cite{cms_thj}. An equally important feature is that the top quark produced via the weak  interaction in $thj$ is left-handed in the SM. It is therefore expected that non-standard top-Higgs couplings will affect the polarisation states of top quark and change the angular distributions of the top quark decay products \cite{ellis_thj}. Such a polarisation asymmetry has been widely used to probe the anomalous top quark interactions at the LHC  \cite{top_pol}. The precise measurement of $thj$ channel opens a new window to probe the top quark Yukawa couplings and new physics at the LHC.


In this work, we examine the current and future constraints on the $\mathcal{CP}$-violating $t\overline{t}h$ couplings based on present LHC data and expected 240GeV TLEP sensitivity respectively.  We investigate the observability of $pp \to thj$ with $h \to b\overline{b}$ for the scalar, pseudoscalar and mixed interactions of top-Higgs. The potential to discriminate such anomalous top-Higgs coupling is studied by performing reconstructed-level Monte Carlo simulations at 14 TeV HL-LHC. This paper is organised as follows: in section 2, we present the Higgs data constraints on the anomalous top quark Yukawa couplings; in section 3, we discuss their observability by analysing $pp \to thj$ production; conclusions are drawn in section 4.


\section{Higgs data Constraints}
In some new physics models, the top quark Yukawa coupling can be different from the SM prediction. The new physics effects on $t\overline{t}h$ coupling can be parameterised by a minimal set of the gauge invariant dimension-six operators \cite{eff}. The most general Lagrangian of the $t\overline{t}h$ interaction in the broken phase can be parameterised as follows:
\begin{equation}
{\cal L} \supset -\frac{y_t}{\sqrt{2}}\overline{t}(\cos\xi+i\gamma^{5}\sin\xi)th,   \qquad \qquad  \xi \in (-\pi,\pi]
\end{equation}
where $y_t$ takes the value $y^{SM}_t=\sqrt{2}m_t/v$ and $\xi =0$ in the SM, with $v\approx 246$ GeV being the vacuum expectation value of the Higgs field. It is useful to define the scalar and pseudoscalar components of the anomalous top-Higgs interaction normalised to the tree-level  SM coupling as  $C_S= y_t \cos\xi/y^{SM}_t$ and $C_P= y_t \sin\xi/y^{SM}_t$ respectively. It should be noted that such $\mathcal{CP}$-violating interactions contribute to the electric dipole moment (EDM). However, the bounds on the coupling $C_P$ depend on the assumption of Higgs couplings to other light fermions \cite{top_cp_review,zupan}. Since these couplings are practically unobservable at the LHC, we do not impose EDM constraints in this work. Other constraints from low-energy physics observables, such as $B_s-\overline{B}_s$ and $B \to X_s \gamma$, remain relatively weak \cite{zupan}.

An obvious consequence of non-standard top-Higgs interaction is that the production rate of $gg \to h$ and decay width of $h \to \gamma\gamma$ will deviate from those in the SM. In Fig.~\ref{red_coup}, we show the dependence of the reduced couplings $C_{hgg}$ and $C_{h\gamma\gamma }$ in terms of $y_t$ and $\xi$. It could be seen that the coupling $C_{hgg}$ at $\xi=\pm \pi/2$ is larger than that at $\xi=0$. The reason is that the pseudoscalar interaction of $t\overline{t}h$ can lead to a larger form factor than the scalar interaction in the calculation of $gg \to h$. We can also notice that when $y_t$ increases, the reduced coupling $C_{hgg}$ becomes larger. However, this is different from the case in the coupling $C_{h\gamma\gamma}$, where the larger $y_t$ will induce a stronger cancellation between top quark loop and $W$ boson loop. 

%%%fig1.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=7mm 8mm 10mm 16mm]{cs_cp_Cg.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=7mm 8mm 10mm 16mm]{cs_cp_Cga.eps}\vspace{-0.5cm}
\caption{Reduced couplings $C_{hgg}$ and $C_{h\gamma\gamma }$ as a function of $y_t$ and $\xi$.}
\label{red_coup}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

We impose the latest Higgs data constraints on the anomalous couplings $C_S$ and $C_P$ by calculating $\chi^2$ with the public package \textsf{HiggsSignals-1.2.0} \cite{higgssignals}, which includes all the available data sets from the ATLAS, CMS, CDF and D{\O}  collaborations. In Fig.~\ref{cpv}, we present the Higgs data constraints on the anomalous couplings $C_S$ and $C_P$ using current Higgs data and the prospect of improving the bounds at TLEP with $\sqrt{s}=240$ GeV. We find that reduced pseudoscalar couplings in the range  $|C_P|>0.6$ have been excluded at 95\% C.L by the current Higgs data and that positive scalar couplings $C_S>0.5$ are strongly favoured, consistent with Ref.~\cite{ellis_thj,Maito_fit,Nishiwaki_fit}. As the $\mathcal{CP}$-phase $\xi$ increases from 0 to $\pi/2$, the 95\% C.L. allowed region for $y_t/y_t^{SM}$ reduces from $0.7$ -- $1.2$ to $0.4$ -- $0.6$. The expected measurement of $C_S$ at 14 TeV HL-LHC (3000 fb$^{-1}$) will further  constrain $C_P$ to the range $|C_P|<0.4$.
To estimate the bounds at TLEP, all measured Higgs couplings  are assumed to be the same as the SM predictions, and the expected measurement uncertainties are taken from Table 1-16 of Ref.~\cite{snowmass}. The main constraints come from the precise determinations of loop induced, reduced $C_{hgg}$ and $C_{h\gamma\gamma}$ couplings at TLEP. From Fig.~\ref{cpv}, we see that the allowed range of $C_P$ at 95\% C.L. shrinks to $|C_P|<0.2$, and $C_S$ is very close to one.


%%%fig2.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h!]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=7mm 8mm 12mm 16mm]{lhc.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=7mm 8mm 12mm 16mm]{tlep.eps}\vspace{-0.5cm}
\caption{The Higgs data constraints on the anomalous couplings $C_S$ and $C_P$ at the LHC and the expected sensitivity of these couplings at 240 GeV TLEP. The solid and dashed lines correspond to 68\% and 95\% C.L. respectively. The shadowed region represents the expected measurement uncertainty at HL-LHC.}
\label{cpv}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



In Fig.~\ref{couplings}, we project the samples in the above 95\% C.L. range allowed by the current Higgs data on the plane of the Higgs-diphoton reduced coupling $C_{h\gamma\gamma}$ versus the $\mathcal{CP}$ phase $\xi$. From Fig.~\ref{couplings}, we see that the effective coupling $C_{h\gamma\gamma}$ can be sizeably enhanced by the constructive contribution of the top-quark loop with $\mathcal{CP}$-violating couplings, reaching a maximal value of $\sim$1.32. The bound on $\xi$ is expected to improve from $|\xi|<0.6\pi$ at the LHC to $|\xi|<0.07\pi$ at 240 GeV TLEP.

%%%fig3.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h!]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=4mm 8mm 12mm 16mm]{cgalhc.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=4mm 8mm 12mm 16mm]{cgatlep.eps}\vspace{-0.5cm}
\caption{Left: The Higgs diphoton reduced coupling $C_{h\gamma\gamma}$ versus $\mathcal{CP}$-violating phase $\xi$  in the 95\% C.L  allowed range in Fig.~\ref{cpv}. The shaded region is the expected measurement uncertainty of $C_{h\gamma\gamma}$ at HL-LHC; Right: The expected constraints on $C_{h\gamma\gamma}$ and $\xi$ at 240 GeV TLEP.}

\label{couplings}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\section{anomalous $t\overline{t}h$ couplings and $thj$ production}
In the numerical calculations we take the SM input parameters as follows \cite{pdg}:
\begin{align}
m_t = 173.07{\rm ~GeV},\quad &m_{Z} =91.1876 {\rm ~GeV}, \quad \alpha(m_Z) = 1/127.9, \\ \nonumber
\sin^{2}\theta_W = 0.231,\quad &m_h =125 {\rm ~GeV}, \quad \alpha_{s}(m_Z)=0.1185.
\end{align}
By performing the Monte Carlo simulation, we investigate the observability of the anomalous top-Higgs couplings through the single top and Higgs associated production at the LHC
\begin{eqnarray}\label{process}
pp \to thj \to b \ell^{+} \nu b \overline{b} j,
\end{eqnarray}
where $j$ denotes the light jets and $\ell^{+} = e^{+},\mu^{+}$. Our signal is characterised by multi-jets (1 forward jet + 3 $b$-jets) + 1 lepton + missing energy (due to the neutrinos) in the final states. Although the $h \to b\overline{b}$ decay mode suffers a loss of efficiency in Higgs mass reconstruction, this shortcoming is mildly compensated by the large branching ratio of $h \to b\overline{b}$. Such a signature resembles the $t\overline{t}h$ topology analysed by ATLAS and CMS collaborations at the LHC Run-I, where at least 3 $b$-jets are required \cite{tth_bb}.

We implement the $\mathcal{CP}$-violating interaction of $t\overline{t}h$ in (\ref{cpv}) by using the package \textsf{FeynRules} \cite{feynrules} and generate the parton-level signal and background events with \textsf{MadGraph5} \cite{mad5}. In Fig.~\ref{Xsection}, we show the resulting the $thj$ production cross section with no cuts on the final state kinematic distribution,  as a function of $\xi$ for a selection of $y_t$ values. The values $y_t=0.7y^{SM}_{t}$ and $y_t=1.2y^{SM}_{t}$ respectively correspond to the 95\% C.L. lower and upper bounds of $y_t$ for $\xi=0$, whilst $y_t=0.4y^{SM}_{t}$ is the lower bound for $\xi=\pi/2$. We can see that the maximal value of the cross section occurs at  $|\xi|=\pi$, due to the constructive interference of the contributions involving the $hWW$ and $ht\overline{t}$ couplings.


%%%fig4.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h]
\centering
\includegraphics[width=.5\textwidth,clip=true,trim=4mm 8mm 14mm 14mm]{crossX}
\caption{$pp\rightarrow thj$ production cross section (fb) as a function of $\mathcal{CP}$ phase $\xi$ at 14 TeV LHC. The conjugated process $\overline{t}hj$ is not included here.}
\label{Xsection}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Parton showering and fast detector simulations are subsequently performed by \textsf{PYTHIA} \cite{pythia} and \textsf{Delphes} \cite{delphes}. Jets are clustered by using the anti-$k_t$ algorithm with a cone radius $\Delta R=0.7$ \cite{anti-kt}. We keep the default cuts setting when generating the parton level events and set both the renormalisation  ($\mu_R$) and factorisation ($\mu_F$) scale to the default event-by-event value and take CTEQ6L as the parton distribution function \cite{cteq}. We adopt the $b$-jet tagging efficiency ($\epsilon_b$) formula \cite{cms-b} that is a function of the transverse momentum and rapidity of the jets, with $\epsilon_b =0$ in the forward region ($|\eta|>2.5$). We also include a misidentification probability of  10\% and 1\% for $c$-jets and light jets respectively. The mis-tag of QCD jets is assumed to be the default value as in \textsf{Delphes}. The number of events generated for both  the signals and backgrounds  in our calculations is $1.2\times 10^6.$

The main SM backgrounds are: (B1) $pp \to t\overline{t}$, which can fake the signal when one light jet from the (anti-)top quark hadronic decay is misidentified as a $b$-jet. (B2) $pp \to tZ(\to b\overline{b})j$, which is an irreducible background but with a pair of $b$-jets coming from $Z$ boson; and (B3) the irreducible QCD process $pp \to tb\overline{b}j$. Since the last two backgrounds have been demonstrated to be small \cite{lee_thj,maltoni_thj2}, we will focus on background (B1). To include the QCD effects, we generate parton-level events of $t\bar{t}$ with up to two jets that are matched to the parton shower using the MLM-scheme \cite{Mangano:2006rw} with merging scale $x_q = 20$ GeV.
We impose the basic cuts on the final states as follows:
\begin{eqnarray}\label{basic}
% \nonumber to remove numbering (before each equation)
  \Delta R_{ij} > 0.4\ ,& \quad  i,j &= b,j \ \text{or}\  \ell \\ \nonumber
  p_{T}^b > 25 \ \text{GeV},&\quad |\eta_b| &<2.5 \\ \nonumber
 p_{T}^\ell > 25 \ \text{GeV},& \quad  |\eta_\ell|&<2.5  \\ \nonumber
 p_{T}^j > 25 \ \text{GeV},& \quad  |\eta_j|&<4.7.
\end{eqnarray}

%%%fig5.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=6mm 6mm 10mm 10mm]{eta.eps}\vspace{-0.5cm}
\caption{The pseudorapidity distributions of the leading jet in the signals and backgrounds.}
\label{eta}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
In Fig.~\ref{eta}, we plot the pseudorapidity distributions of the leading jet in the signals and backgrounds. It can be observed that most $t\overline{t}$ events of have a leading jet in the central region, which  differs significantly from the signal, where a forward spectator jet  accompanies the top quark and Higgs boson. The pseudorapidity of the leading jet is therefore required to satisfy $2.5<|\eta_{j_1}|<4.7$ in order to reduce the $t\overline{t}$ background.

%%%fig6.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h!]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=6mm 2mm 10mm 10mm]{mbbj_before.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=6mm 2mm 10mm 10mm]{mbb_before.eps}
\vspace{-0.5cm}
\caption{The normalised invariant mass distributions of $M^{rec}_{b\overline{b}}$ and $M^{rec}_{b\overline{b}j}$ with only basic cuts. Here the two $b$-jets are those rejected by the minimisation of $M_{b\ell}$.}
\label{before}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Another cut which further suppresses the $t\overline{t}$ background is the invariant mass cut on the two $b$-jets from the Higgs boson decay. As proposed in Ref.~\cite{lee_thj}, the $b$-jet from the top quark decay can be tagged by selecting the minimal one among the invariant masses of each $b$-jet and the lepton, which should also satisfy $M^{min}_{b\ell}<200$ GeV. The remaining two $b$-jets are the considered as possible daughters of the Higgs boson for the signal. Given that the third $b$-jet in the $t\overline{t}$ background comes mainly from the misidentification of the jets in the top quark hadronic decay, the invariant mass $M^{rej}_{b\overline{b}j}$ and the two $b$-jets rejected by the minimisation of $M_{b\ell}$ should have a peak around $m_t$ for $t\overline{t}$, as is evident in Fig.~\ref{before}. We further find that the signal $M^{rej}_{b\overline{b}}$  invariant mass peaks are more narrow than those of the backgrounds but are still relatively broad around the Higgs mass, reducing the effectiveness of the cut $|M^{rej}_{b\overline{b}}-m_h|<15$ GeV in enhancing the observability of the signals.


Similar to Fig.~\ref{before}, we display $M^{rej}_{b\overline{b}j}$ and $M^{rej}_{b\overline{b}}$ distributions with a forward jet cut $2.5<|\eta_{j_1}|<4.7$ in Fig.~\ref{after}. Comparing with Fig.~\ref{before}, we can find that the peak of $M^{rej}_{b\overline{b}j}$ moves towards the high invariant mass region. This indicates that the selected forward jets in $t\overline{t}$  events are not from the top quark hadronic decay. We claim that the $M^{rej}_{b\overline{b}j}$ cut will not be very effective in improving the significance of the signal after the forward jet cut. The $M^{rej}_{b\overline{b}}$ distribution of the backgrounds becomes slightly more flat than the one in Fig.~\ref{before}.

%%%fig7.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h!]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=6mm 2mm 10mm 10mm]{mbbj_after.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=6mm 2mm 10mm 10mm]{mbb_after.eps}\vspace{-0.5cm}
\caption{Same mass distributions as Fig.~\ref{before}, but with an addition forward jet selection $2.5<|\eta_{j_1}|<4.7$.}
\label{after}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

In Tab.~\ref{cutflow}, we summarise the cut-flow cross sections of the signal and backgrounds for 14 TeV LHC. Considering that  the 95\% C.L. from the current LHC data still allows the $\mathcal{CP}$-violating phase $\xi$ to vary within $|\xi| \lesssim0.6 \pi$ (c.f. Tab.~\ref{cpv}), we take three benchmark points $\xi = 0$, $\pi/4$ and $\pi/2$ and assume $y_t =y^{SM}_t$ to demonstrate the observability of our signals. From Tab.~\ref{cutflow}, we can find that: (1) Since there is always a top quark in the signal and backgrounds, the identification procedure of $b$-jet from top quark using $M^{min}_{b\ell}$ reduces both signal and background slightly;
(2) The  {$t\overline{t}$}  events can be further reduced by about one order with the forward jet selection, whilst the signal only loses about $1/3$ events;
(3) The Higgs mass window cut can further remove about $3/4$  of the background  events but keep almost 1/3 of events of the signal.

%%%table1%%%%%%%%%%%%%%%%%%%%
\begin{table}[ht!]
\fontsize{12pt}{8pt}\selectfont
\begin{center}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
{\renewcommand{\arraystretch}{1.5}
\begin{tabular}{ C{1.5cm} C{2.75cm} C{2.75cm} |C{1.5cm}C{1.5cm}C{1.5cm} | C{3cm}   }
\cline{1-6}
\hline
&\multicolumn{2}{c|}{\multirow{3}{*}{Cuts}}&\multicolumn{4}{c}{$\sigma$ [fb] } \\\cline{4-7}
&&&\multicolumn{3}{c|}{$thj$} &\multirow{2}{*}{{$t\bar{t}_{\rm matched}$} } \\\cline{4-6}
&&&{$\xi=0$} & {$\xi=\pi/4$} &{$\xi=\pi/2$}      \\\cline{1-7}
\multirow{4}{*}{(C1)} &$ \Delta R_{ij} > 0.4$,  & $i,j = b,j \ \text{or}\  \ell$ & \multirow{4}{*}{0.3169}&\multirow{4}{*}{0.6700}
& \multirow{4}{*}{2.1860}&\multirow{4}{*}{712.4}\\
&   $p_{T}^b > 25 \ \text{GeV}, $     &$|\eta_b|<2.5$&&&&\\
&     $p_{T}^\ell > 25 \ \text{GeV}$,    &$|\eta_\ell|<2.5$&&&&\\
&    $ p_{T}^j > 25 \ \text{GeV}$,    &$|\eta_j|<4.7$&&&&\\    \hline
(C2)&      \multicolumn{2}{ c| }{ $M_{b\ell}<200$ GeV} &0.3152&0.6582&2.1446&708.7\\ \hline
(C3)&      \multicolumn{2}{ c| }{ $ |\eta_j|>2.5$} &0.1492&0.3314&1.1002&80.33\\ \hline
(C4)& \multicolumn{2}{c|}{$ |M_{b_1\overline{b}_2}-m_h|< 15 \ \text{GeV}$}&0.0443&0.1102&0.3762&15.82\\\hline
&  \multicolumn{2}{ c| }{$S/\sqrt{B}$ with 3000 fb$^{-1}$ }&0.610&1.517&5.180\\\hline
&  \multicolumn{2}{ c| }{$S/ B$}&0.28\% & 0.70\% & 2.38\%\\
\hline
\end{tabular}}
\caption{Cutflow of the cross sections (fb) for the signals ($\xi=0,\pi/4$ and $\pi/2$) and the backgrounds at 14 TeV LHC. The conjugate process $pp\rightarrow \overline{t}hj$ has been included. \label{cutflow}}
\end{center}
\end{table}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%

For each signal point, we calculate the statistical significance $S/\sqrt{B}$ and systematic significance $S/B$ for the luminosity $L = 3000~{\rm fb}^{-1}$. %, where $B$ represents the number of background events.
From Tab.~\ref{cutflow}, we can see the observability of the pure pseudoscalar interaction ($\xi=\pi/2$)  at 14 TeV HL-LHC is the most promising, with a $\sim 5\sigma$ level statistical significance but a low systematic significance $\sim 2.4\%$. Furthermore, it should be noted that when $\xi=\pi/2$, the values of $y_t/y^{SM}_{t}$ are required to be within the range $0.4 -0.6$ to remain consistent with the current Higgs data. This will  reduce the $thj$  cross section of by a factor $\sim 2/3$,  making the observation more challenging at the LHC.

Since the $\mathcal{CP}$-violating interaction described by (\ref{cpv}) can affect the chirality of $tbW$ coupling through the interference between different Feynman diagrams, we will investigate the top quark polarisation asymmetry in the process $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$. The angular distribution of the lepton from a polarised top quark is given by:
\begin{equation}
   \frac{1}{\Gamma}\frac{d\Gamma}{d\cos\theta_\ell}=\frac{1}{2}(1+\mathcal{P}_t\kappa_\ell\cos\theta_\ell).
\end{equation}
where  the lepton spin analysing power $\kappa_\ell$ is one at tree level in the SM, $\theta_\ell$ is the angle between the direction of the top quark and the lepton momenta in the rest frame of the top quark and $\mathcal{P}_t$ is the spin asymmetry. We reconstruct the top quark rest frame by minimising $\chi^2$, which is defined as:
\begin{equation}
   \chi^2= \bigg( \frac{m_t-m_{\ell\nu_\ell b} }{\Delta {m_t}}\bigg)^2,
\end{equation}
where $\Delta{m_t}$ is taken as the SM top quark decay width \cite{pdg}. With the on-shell condition of the $W$ boson and the top quark, the longitudinal momentum of the neutrino $p_{\nu L}$ can be determined as:
\begin{equation}
  p_{\nu L} = \frac{1}{2p_{\ell T}^2}\bigg( A_{W} p_{ \ell L} \pm E_\ell\sqrt{A_{W}^2 - 4 p_{\ell T}^2  {\not\!\!{E}}^2_T}\bigg),\label{neutrino}
\end{equation}
where $A_W= m_W^2 + 2 \mathbf{p}_{\ell T}\cdot { \not\!\! \mathbf{E}_T}$. The ambiguity of the sign in (\ref{neutrino}) can be removed by the minimal
$\chi^2$ requirement \cite{qinghong}.

%%%fig8.eps%%%%%%%%%%%%%%%%%%%%
\begin{figure}[h!]
\centering
\includegraphics[width=.45\textwidth,clip=true,trim=8mm 6mm 10mm 10mm]{prt_pol.eps}
\includegraphics[width=.45\textwidth,clip=true,trim=8mm 6mm 10mm 10mm]{rec_pol.eps}
\caption{The angular distributions of the lepton from the top quark decay in the signal $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$ at parton level (left panel) and reconstruction level (right panel) after the cuts.}
\label{pol}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

In Fig.~\ref{pol}, we plot the lepton angular distributions $\cos\theta_{\ell}$ for the $\mathcal{CP}$ phase $\xi=0, \ \pi/4$ and $\pi/2$ in the signal $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$  at parton level  and reconstruction level respectively after the cuts (C3) and (C4) (c.f. Tab.~\ref{cutflow}). From Fig.~\ref{pol}, we can see that the direction of the lepton is inclined to be opposite to its parent top quark for $\xi=0$, which corresponds to the SM top-Higgs interaction. However, the mixed and pseudoscalar interactions will affect the polarisation state of the top quark and change the slopes such that the number of events with $\cos\theta_\ell > 0$ is larger than those with $\cos\theta_\ell < 0$. The differences between the slopes  are diluted from the parton level to the reconstruction level.

Based on the angular distributions, we can further define the lepton forward-backward (FB) asymmetry:
\begin{equation}
\mathcal{A}^{\ell}_{FB}=\frac{\sigma(\cos\theta_{\ell}>0)-\sigma(\cos\theta_{\ell}<0)}{\sigma(\cos\theta_{\ell}>0)+\sigma(\cos\theta_{\ell}<0)}
\end{equation}
In Tab.~\ref{afb}, we present the values of $A^{\ell}_{FB}$ for $\xi=0,\pi/4$ and $\pi/2$ in the signal {$pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$}  at 14 TeV LHC. From Tab.~\ref{afb}, we can see that both of the scalar and pseudoscalar top-Higgs interaction can induce large forward-backward asymmetries but with different signs, reaching -17.6\% and 13.7\% respectively. The measurement of the lepton forward-backward asymmetry can distinguish the scalar and pseudoscalar top-Higgs interactions at the LHC.


%%%table2%%%%%%%%%%%%%%%%%%%%
\begin{table}[c h!]
\begin{center}
{\renewcommand{\arraystretch}{1.25}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}

\begin{tabular}{  C{1cm} C{3cm}  C{3cm}  C{2cm}}
\hline
 $\xi$& $\sigma(\cos\theta>0)$ [fb] & $\sigma(\cos\theta<0)$ [fb]  & $\mathcal{A}^{\ell}_{FB}$ (\%) \\
\hline
{$0$} &0.01458 &0.0208 &-17.6\\\hline
{$\pi/4$} &0.04687 &0.03991 &8.0\\\hline
{$\pi/2$} &0.1681 &0.1276 &13.7\\\hline
\hline
\end{tabular}}
\caption{The reconstructed-level forward-backward asymmetry $\mathcal{A}^{\ell}_{FB}$ at 14 TeV LHC.}\label{afb}
\end{center}
\end{table}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



\section{\label{sec:level1}conclusion}

In this paper, we have obtained constraints on the $\mathcal{CP}$-violating top-Higgs couplings using the current Higgs data and found that values of $\mathcal{CP}$-violating phase $|\xi| > 0.6\pi$ are already excluded at  95\% C.L.. We  expected TLEP to improve this exclusion region to $|\xi |>0.07\pi$. With current constraints on $\xi$, we further investigate the observability of the scalar, pseudoscalar and mixed top-Higgs interactions through the channel $pp \to t(\to \ell^+\nu_\ell b)h(\to b\overline{b})j$. We found that it is most promising to observe pure pseudoscalar interactions at the HL-LHC but it is still challenging due to a low $S/B$ ratio. However, the anomalous top-Higgs couplings can lead to sizeable differences in forward-backward asymmetries and can be distinguished by measuring the lepton angular distributions from polarised top quarks at 14 TeV LHC.

\section*{Acknowledgement}
This work was supported by the Australian Research Council. Lei Wu is also supported by the National Natural Science Foundation of China (NNSFC) under grants Nos. 11222548, 11275057 and 11305049, by Specialised Research Fund for the Doctoral Program of Higher Education under Grant No. 20134104120002.

\begin{thebibliography}{99}

\bibitem{higgs-atlas}
G. Aad et al.(ATLAS Collaboration), Phys. Lett. B \textbf{710}, 49
(2012).

\bibitem{higgs-cms}
S. Chatrachyan et al.(CMS Collaboration), Phys. Lett. B
\textbf{710}, 26 (2012).


\bibitem{review} the recent reviews, see examples:
  S.~Dawson, A.~Gritsan, H.~Logan, J.~Qian, C.~Tully, R.~Van Kooten, A.~Ajaib and A.~Anastassov {\it et al.},
  %``Working Group Report: Higgs Boson,''
  arXiv:1310.8361 [hep-ex];
  %%CITATION = ARXIV:1310.8361;%%
  %43 citations counted in INSPIRE as of 24 May 2014
  C.~Englert, A.~Freitas, M.~Muhlleitner, T.~Plehn, M.~Rauch, M.~Spira and K.~Walz,
  %``Precision Measurements of Higgs Couplings: Implications for New Physics Scales,''
  arXiv:1403.7191 [hep-ph];
  %%CITATION = ARXIV:1403.7191;%%
  %5 citations counted in INSPIRE as of 24 May 2014

\bibitem{hf} see recent examples at the TLEP and ILC:
  V.~Barger, L.~L.~Everett, H.~E.~Logan and G.~Shaughnessy,
  %``Scrutinizing h(125) in Two Higgs Doublet Models at the LHC, ILC, and Muon Collider,''  P
  hys.\ Rev.\ D {\bf 88}, 115003 (2013)  [arXiv:1308.0052 [hep-ph]];
  %%CITATION = ARXIV:1308.0052;%%  %22 citations counted in INSPIRE as of 24 May 2014
  A.~Kobakhidze and J.~Yue,
  %``Excluding a Generic Spin-2 Higgs Impostor,''
  Phys.\ Lett.\ B {\bf 727}, 456 (2013)  [arXiv:1310.0151 [hep-ph]];
  %%CITATION = ARXIV:1310.0151;%%  %2 citations counted in INSPIRE as of 24 May 2014
  N.~Liu, J.~Ren, L.~Wu, P.~Wu and J.~M.~Yang,
  %``Full one-loop electroweak corrections to $e^+e^- \to ZH\gamma$ at a Higgs factory,''
  JHEP {\bf 1404}, 189 (2014)  [arXiv:1311.6971 [hep-ph]];
  %%CITATION = ARXIV:1311.6971;%%
  %2 citations counted in INSPIRE as of 24 May 2014
  Z.~Heng, L.~Shang and P.~Wan,
  %``Pair production of a 125 GeV Higgs boson in MSSM and NMSSM at the ILC,''
  JHEP {\bf 1310}, 047 (2013)  [arXiv:1306.0279 [hep-ph]];
  %%CITATION = ARXIV:1306.0279;%%
  %5 citations counted in INSPIRE as of 24 May 2014
  S.~L.~Hu, N.~Liu, J.~Ren and L.~Wu,
  %``Probing Higgs couplings to diphoton and Z-photon from Higgs$+$photon production at a Higgs factory,''
  arXiv:1402.3050 [hep-ph];
  %%CITATION = ARXIV:1402.3050;%%
  L.~Wang and X.~-F.~Han,
  %``Study of the heavy CP-even Higgs with mass 125 GeV in two-Higgs-doublet models at the LHC and ILC,''
  arXiv:1404.7437 [hep-ph];
  %%CITATION = ARXIV:1404.7437;%%
  %1 citations counted in INSPIRE as of 24 May 2014
  C.~Han, A.~Kobakhidze, N.~Liu, L.~Wu and B.~Yang,
  %``Constraining Top partner and Naturalness at the LHC and TLEP,''
  arXiv:1405.1498 [hep-ph];
  %%CITATION = ARXIV:1405.1498;%%
  J.~Cao, Z.~Heng, D.~Li, L.~Shang and P.~Wu,
  %``Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs factory in the Minimal Dilaton Model,''
  arXiv:1405.4489 [hep-ph];
  %%CITATION = ARXIV:1405.4489;%%

\bibitem{tth_old}
  W.~J.~Marciano and F.~E.~Paige,
  %``Associated production of Higgs bosons with t anti-t pairs,''
  Phys.\ Rev.\ Lett.\  {\bf 66}, 2433 (1991);
  %%CITATION = PRLTA,66,2433;%%
  %137 citations counted in INSPIRE as of 24 May 2014
  J.~Dai, J.~F.~Gunion and R.~Vega,
  %``Using b tagging to detect t anti-t Higgs production with Higgs ---> b anti-b,''
  Phys.\ Rev.\ Lett.\  {\bf 71}, 2699 (1993)  [hep-ph/9306271];
  %%CITATION = HEP-PH/9306271;%%
  %62 citations counted in INSPIRE as of 24 May 2014
  J.~Goldstein, C.~S.~Hill, J.~Incandela, S.~J.~Parke, D.~L.~Rainwater and D.~Stuart,
  %``$p\bar{p}\to t\bar{t}H$: A Discovery mode for the Higgs boson at the Tevatron,''
  Phys.\ Rev.\ Lett.\  {\bf 86}, 1694 (2001)  [hep-ph/0006311];
  %%CITATION = HEP-PH/0006311;%%
  %55 citations counted in INSPIRE as of 24 May 2014
  A.~Belyaev and L.~Reina,
  %``pp ---> t anti-t H, H ---> tau+ tau-: Toward a model independent determination of the Higgs boson couplings at the LHC,''
  JHEP {\bf 0208}, 041 (2002)  [hep-ph/0205270];
  %%CITATION = HEP-PH/0205270;%%
  %101 citations counted in INSPIRE as of 24 May 2014
  F.~Maltoni, D.~L.~Rainwater and S.~Willenbrock,
  %``Measuring the top quark Yukawa coupling at hadron colliders via $t\bar{t}H,H\to W^+W^-$,''
  Phys.\ Rev.\ D {\bf 66}, 034022 (2002)  [hep-ph/0202205];
  %%CITATION = HEP-PH/0202205;%%
  %62 citations counted in INSPIRE as of 24 May 2014
  V.~Drollinger, T.~Muller and D.~Denegri,
  %``Searching for Higgs bosons in association with top quark pairs in the H0 ---> b anti-b decay mode,''
  hep-ph/0111312;
  %%CITATION = HEP-PH/0111312;%%
  %87 citations counted in INSPIRE as of 24 May 2014
  W.~Beenakker, S.~Dittmaier, M.~Kramer, B.~Plumper, M.~Spira and P.~M.~Zerwas,
  %``NLO QCD corrections to t anti-t H production in hadron collisions,''
   Nucl.\ Phys.\ B {\bf 653}, 151 (2003)  [hep-ph/0211352].
   %%CITATION = HEP-PH/0211352;%%
   %250 citations counted in INSPIRE as of 24 May 2014


\bibitem{tth_new}
  P.~Agrawal, S.~Bandyopadhyay and S.~P.~Das,
  %``Multilepton Signatures of the Higgs Boson through its Production in Association with a Top-quark Pair,''
  Phys.\ Rev.\ D {\bf 88}, 093008 (2013)  [arXiv:1308.3043 [hep-ph]];
  %%CITATION = ARXIV:1308.3043;%%
  %5 citations counted in INSPIRE as of 24 May 2014
  S.~Biswas, R.~Frederix, E.~Gabrielli and B.~Mele,
  %``Enhancing the ttH signal through top-quark spin polarization effects at the LHC,''
  arXiv:1403.1790 [hep-ph];
  %%CITATION = ARXIV:1403.1790;%%
  M.~V.~Garzelli, A.~Kardos, C.~G.~Papadopoulos and Z.~Trocsanyi,
  %``Standard Model Higgs boson production in association with a top anti-top pair at NLO with parton showering,''
  Europhys.\ Lett.\  {\bf 96}, 11001 (2011)  [arXiv:1108.0387 [hep-ph]];
  %%CITATION = ARXIV:1108.0387;%%
  %34 citations counted in INSPIRE as of 24 May 2014
  R.~Frederix, S.~Frixione, V.~Hirschi, F.~Maltoni, R.~Pittau and P.~Torrielli,
  %``Scalar and pseudoscalar Higgs production in association with a top-antitop pair,''
  Phys.\ Lett.\ B {\bf 701}, 427 (2011)  [arXiv:1104.5613 [hep-ph]];
  %%CITATION = ARXIV:1104.5613;%%
  %58 citations counted in INSPIRE as of 24 May 2014
  C.~Degrande, J.~M.~Gerard, C.~Grojean, F.~Maltoni and G.~Servant,
  %``Probing Top-Higgs Non-Standard Interactions at the LHC,''
  JHEP {\bf 1207}, 036 (2012)  [Erratum-ibid.\  {\bf 1303}, 032 (2013)]  [arXiv:1205.1065 [hep-ph]];
  %%CITATION = ARXIV:1205.1065;%%
  %25 citations counted in INSPIRE as of 24 May 2014
  D.~Curtin, J.~Galloway and J.~G.~Wacker,
  %``Measuring the tth coupling from SSDL+2b measurements,''
  Phys.\ Rev.\ D {\bf 88}, 093006 (2013)  [arXiv:1306.5695 [hep-ph]];
  %%CITATION = ARXIV:1306.5695;%%
  %11 citations counted in INSPIRE as of 24 May 2014
  J.~Adelman, A.~Loginov, P.~Tipton and J.~Vasquez,
  %``Study of $t\bar{t}H$ ($H \to \mu^+ \bar{\mu}^-$) in the three lepton channel at $\sqrt{s}=14$ TeV; A Snowmass white paper,''
  arXiv:1310.1132 [hep-ex];
  %%CITATION = ARXIV:1310.1132;%%
  %3 citations counted in INSPIRE as of 24 May 2014

\bibitem{atlas_tth}
ATLAS Collaboration [ATLAS Collaboration], ATLAS-CONF-2014-011.


\bibitem{ttj}
  CMS Collaboration [CMS Collaboration],
  %``First Measurement of the cross section ratio ttbb/ttjj in pp Collisions at sqrt{s,''
  CMS-PAS-TOP-12-024.
  %%CITATION = CMS-PAS-TOP-12-024;%%
  %14 citations counted in INSPIRE as of 24 May 2014


\bibitem{thj_old}
  G.~Bordes and B.~van Eijk,
  %``On the associate production of a neutral intermediate mass Higgs boson with a single top quark at the LHC and SSC,''
  Phys.\ Lett.\ B {\bf 299}, 315 (1993);
  %%CITATION = PHLTA,B299,315;%%
  %15 citations counted in INSPIRE as of 24 May 2014
  A.~Ballestrero and E.~Maina,
  %``t anti-b H production for an intermediate mass Higgs,''
  Phys.\ Lett.\ B {\bf 299}, 312 (1993);
  %%CITATION = PHLTA,B299,312;%%
  %16 citations counted in INSPIRE as of 24 May 2014
  W.~J.~Stirling and D.~J.~Summers,
  %``Production of an intermediate mass Higgs boson in association with a single top quark at LHC and SSC,''
  Phys.\ Lett.\ B {\bf 283}, 411 (1992);
  %%CITATION = PHLTA,B283,411;%%
  %19 citations counted in INSPIRE as of 24 May 2014
  J.~L.~Diaz-Cruz and O.~A.~Sampayo,
  %``Associated production of the Higgs boson with t anti-b at hadron colliders,''
  Phys.\ Lett.\ B {\bf 276}, 211 (1992).
  %%CITATION = PHLTA,B276,211;%%
  %10 citations counted in INSPIRE as of 24 May 2014

\bibitem{maltoni_thj1}
  F.~Maltoni, K.~Paul, T.~Stelzer and S.~Willenbrock,
  %``Associated production of Higgs and single top at hadron colliders,''
  Phys.\ Rev.\ D {\bf 64}, 094023 (2001)  [hep-ph/0106293].
  %%CITATION = HEP-PH/0106293;%%
  %35 citations counted in INSPIRE as of 24 May 2014

\bibitem{maltoni_thj2}
  M.~Farina, C.~Grojean, F.~Maltoni, E.~Salvioni and A.~Thamm,
  %``Lifting degeneracies in Higgs couplings using single top production in association with a Higgs boson,''
  JHEP {\bf 1305}, 022 (2013)  [arXiv:1211.3736 [hep-ph]].
  %%CITATION = ARXIV:1211.3736;%%
  %32 citations counted in INSPIRE as of 24 May 2014

\bibitem{biswas_thj}
  S.~Biswas, E.~Gabrielli and B.~Mele,
  %``Single top and Higgs associated production as a probe of the Htt coupling sign at the LHC,''
  JHEP {\bf 1301}, 088 (2013)  [arXiv:1211.0499 [hep-ph]].
  %%CITATION = ARXIV:1211.0499;%%
  %26 citations counted in INSPIRE as of 24 May 2014

\bibitem{ellis_thj}
  J.~Ellis, D.~S.~Hwang, K.~Sakurai and M.~Takeuchi,
  %``Disentangling Higgs-Top Couplings in Associated Production,''
  JHEP {\bf 1404}, 004 (2014)  [arXiv:1312.5736 [hep-ph]].  %%CITATION = ARXIV:1312.5736;%%  %9 citations counted in INSPIRE as of 24 May 2014

\bibitem{englert}
  C.~Englert and E.~Re,
  %``Bounding the top Yukawa with Higgs-associated single-top production,''
  Phys.\ Rev.\ D {\bf 89}, 073020 (2014)  [arXiv:1402.0445 [hep-ph]];
  %%CITATION = ARXIV:1402.0445;%%
  %3 citations counted in INSPIRE as of 26 May 2014


\bibitem{lee_thj}
  J.~Chang, K.~Cheung, J.~S.~Lee and C.~-T.~Lu,
  %``Probing the Top-Yukawa Coupling in Associated Higgs production with a Single Top Quark,''
  JHEP {\bf 1405}, 062 (2014)  [arXiv:1403.2053 [hep-ph]];
  %%CITATION = ARXIV:1403.2053;%%
  %1 citations counted in INSPIRE as of 24 May 2014

\bibitem{eff}
  J.~A.~Aguilar-Saavedra,
  %``A Minimal set of top-Higgs anomalous couplings,''
  Nucl.\ Phys.\ B {\bf 821}, 215 (2009)  [arXiv:0904.2387 [hep-ph]];
  %%CITATION = ARXIV:0904.2387;%%
  %57 citations counted in INSPIRE as of 25 May 2014
  C.~Zhang, N.~Greiner and S.~Willenbrock,
  %``Constraints on Non-standard Top Quark Couplings,''
  Phys.\ Rev.\ D {\bf 86} (2012) 014024
  [arXiv:1201.6670 [hep-ph]];
  %%CITATION = ARXIV:1201.6670;%%
  %24 citations counted in INSPIRE as of 27 May 2014
   X.~Zhang, S.~K.~Lee, K.~Whisnant and B.~L.~Young,
  %``Phenomenology of a nonstandard top quark Yukawa coupling,''
  Phys.\ Rev.\ D {\bf 50} (1994) 7042
  [hep-ph/9407259];
  %%CITATION = HEP-PH/9407259;%%
   P.~Agrawal, S.~Mitra and A.~Shivaji,
  %``Effect of Anomalous Couplings on the Associated Production of a Single Top Quark and a Higgs Boson at the LHC,''
  JHEP {\bf 1312} (2013) 077
  [arXiv:1211.4362 [hep-ph]];
  %%CITATION = ARXIV:1211.4362;%%
  %9 citations counted in INSPIRE as of 16 Jun 2014
   Y.~Wang, F.~P.~Huang, C.~S.~Li, B.~H.~Li, D.~Y.~Shao and J.~Wang,
  %``Constraints on flavor-changing neutral-current $Htq$ couplings from the signal of $tH$ associated production with QCD next-to-leading order accuracy at the LHC,''
  Phys.\ Rev.\ D {\bf 86} (2012) 094014
  [arXiv:1208.2902 [hep-ph]];
  %%CITATION = ARXIV:1208.2902;%%
  %4 citations counted in INSPIRE as of 16 Jun 2014
  G.~Bhattacharyya, D.~Das and P.~B.~Pal,
  %``Modified Higgs couplings and unitarity violation,''
  Phys.\ Rev.\ D {\bf 87} (2013) 011702
  [arXiv:1212.4651 [hep-ph]].
  %%CITATION = ARXIV:1212.4651;%%
  %9 citations counted in INSPIRE as of 28 Aug 2014



\bibitem{cpv_model1}
  A.~Djouadi,
  %``The Anatomy of electro-weak symmetry breaking. II. The Higgs bosons in the minimal supersymmetric model,''
  Phys.\ Rept.\  {\bf 459}, 1 (2008)  [hep-ph/0503173];
  %%CITATION = HEP-PH/0503173;%%
  %685 citations counted in INSPIRE as of 25 May 2014
  A.~Djouadi and G.~Moreau,
  %``The couplings of the Higgs boson and its CP properties from fits of the signal strengths and their ratios at the 7+8 TeV LHC,''
  arXiv:1303.6591 [hep-ph].  %%CITATION = ARXIV:1303.6591;%%  %80 citations counted in INSPIRE as of 25 May 2014

\bibitem{cpv_model2}
  D.~McKeen, M.~Pospelov and A.~Ritz,
  %``Modified Higgs branching ratios versus CP and lepton flavor violation,''
  Phys.\ Rev.\ D {\bf 86}, 113004 (2012)  [arXiv:1208.4597 [hep-ph]];
  %%CITATION = ARXIV:1208.4597;%%
  %35 citations counted in INSPIRE as of 25 May 2014

\bibitem{cpv_model3}
  A.~Celis, V.~Ilisie and A.~Pich,
  %``LHC constraints on two-Higgs doublet models,''
  JHEP {\bf 1307}, 053 (2013)  [arXiv:1302.4022 [hep-ph]];
  %%CITATION = ARXIV:1302.4022;%%
  %61 citations counted in INSPIRE as of 25 May 2014

\bibitem{cpv_model4}
  J.~Shu and Y.~Zhang,
  %``Impact of a CP Violating Higgs Sector: From LHC to Baryogenesis,''
  Phys.\ Rev.\ Lett.\  {\bf 111}, no. 9, 091801 (2013)  [arXiv:1304.0773 [hep-ph]].
  %%CITATION = ARXIV:1304.0773;%%
  %24 citations counted in INSPIRE as of 25 May 2014


\bibitem{archil}
  A.~Kobakhidze,
  %``Standard Model with a distorted Higgs sector and the enhanced Higgs diphoton decay rate,''
  arXiv:1208.5180 [hep-ph].
  %%CITATION = ARXIV:1208.5180;%%
  %13 citations counted in INSPIRE as of 25 May 2014

\bibitem{cms_thj}
CMS Collaboration [CMS Collaboration], CMS-PAS-HIG-14-001.

\bibitem{top_pol} see recent examples:
  A.~Prasath, R.~M.~Godbole and S.~D.~Rindani,
  %``Top polarisation measurement and anomalous $Wtb$ coupling,''
  arXiv:1405.1264 [hep-ph];
  %%CITATION = ARXIV:1405.1264;%%
  %1 citations counted in INSPIRE as of 25 May 2014
  J.~A.~Aguilar-Saavedra and S.~A.~dos Santos,
  %``New directions for top quark polarization in the $t$-channel process,''
  arXiv:1404.1585 [hep-ph];
  %%CITATION = ARXIV:1404.1585;%%
  %1 citations counted in INSPIRE as of 26 May 2014
  S.~Biswas, R.~Frederix, E.~Gabrielli and B.~Mele,
  %``Enhancing the ttH signal through top-quark spin polarization effects at the LHC,''
  arXiv:1403.1790 [hep-ph];
  %%CITATION = ARXIV:1403.1790;%%
  W.~Bernreuther and Z.~-G.~Si,
  %``Top quark spin correlations and polarization at the LHC: standard model predictions and effects of anomalous top chromo moments,''
  Phys.\ Lett.\ B {\bf 725}, 1-3, 115 (2013)  [arXiv:1305.2066 [hep-ph]];
  %%CITATION = ARXIV:1305.2066;%%
  %9 citations counted in INSPIRE as of 26 May 2014
  Q.~-H.~Cao, X.~Wan, X.~-p.~Wang and S.~-h.~Zhu,
  %``Searching for Charged Higgs Boson in Polarized Top Quark,''
  Phys.\ Rev.\ D {\bf 87}, 5, 055022 (2013)  [arXiv:1301.6608 [hep-ph]];
  %%CITATION = ARXIV:1301.6608;%%
  %4 citations counted in INSPIRE as of 26 May 2014
  B.~Yang and N.~Liu,
  %``One-loop effects on top pair production in the littlest Higgs model with T-parity at the LHC,''
  arXiv:1210.5120 [hep-ph];
  %%CITATION = ARXIV:1210.5120;%%
  %3 citations counted in INSPIRE as of 25 May 2014
  J.~A.~Aguilar-Saavedra and R.~V.~Herrero-Hahn,
  %``Model-independent measurement of the top quark polarisation,''
  Phys.\ Lett.\ B {\bf 718}, 983 (2013)  [arXiv:1208.6006 [hep-ph]];
  %%CITATION = ARXIV:1208.6006;%%
  %6 citations counted in INSPIRE as of 25 May 2014
  X.~-Q.~Li, Z.~-G.~Si, K.~Wang, L.~Wang, L.~Zhang and G.~Zhu,
  %``Light Top Squark in Precision Top Quark Sample,''
  Phys.\ Rev.\ D {\bf 89}, 077703 (2014)
  [arXiv:1311.6874 [hep-ph]];
  %%CITATION = ARXIV:1311.6874;%%
  %4 citations counted in INSPIRE as of 06 Jun 2014
  I.~Low,
  %``Polarized Charginos (and Tops) in Stop Decays,''
  Phys.\ Rev.\ D {\bf 88} (2013) 095018
  [arXiv:1304.0491 [hep-ph]];
  %%CITATION = ARXIV:1304.0491;%%
  %8 citations counted in INSPIRE as of 05 Jun 2014
  R.~M.~Godbole, L.~Hartgring, I.~Niessen and C.~D.~White,
  %``Top polarisation studies in $H^-t$ and $Wt$ production,''
  JHEP {\bf 1201}, 011 (2012)  [arXiv:1111.0759 [hep-ph]];
  %%CITATION = ARXIV:1111.0759;%%
  %14 citations counted in INSPIRE as of 25 May 2014
  J.~Cao, K.~Hikasa, L.~Wang, L.~Wu and J.~M.~Yang,
  %``Testing new physics models by top charge asymmetry and polarization at the LHC,''
  Phys.\ Rev.\ D {\bf 85}, 014025 (2012)  [arXiv:1109.6543 [hep-ph]];
  %%CITATION = ARXIV:1109.6543;%%
  %27 citations counted in INSPIRE as of 25 May 2014
  D.~Krohn, T.~Liu, J.~Shelton and L.~-T.~Wang,
  %``A Polarized View of the Top Asymmetry,''
  Phys.\ Rev.\ D {\bf 84}, 074034 (2011)  [arXiv:1105.3743 [hep-ph]];
  %%CITATION = ARXIV:1105.3743;%%
  %74 citations counted in INSPIRE as of 26 May 2014
  J.~Cao, L.~Wu and J.~M.~Yang,
  %``New physics effects on top quark spin correlation and polarization at the LHC: a comparative study in different models,''
  Phys.\ Rev.\ D {\bf 83}, 034024 (2011)  [arXiv:1011.5564 [hep-ph]];
  %%CITATION = ARXIV:1011.5564;%%
  %46 citations counted in INSPIRE as of 25 May 2014
  D.~Choudhury, R.~M.~Godbole, S.~D.~Rindani and P.~Saha,
  %``Top polarization, forward-backward asymmetry and new physics,''
  Phys.\ Rev.\ D {\bf 84}, 014023 (2011)  [arXiv:1012.4750 [hep-ph]].
  %%CITATION = ARXIV:1012.4750;%%
  %69 citations counted in INSPIRE as of 26 May 2014
  D.~-W.~Jung, P.~Ko and J.~S.~Lee,
  %``Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron,''
  Phys.\ Lett.\ B {\bf 701}, 248 (2011)  [arXiv:1011.5976 [hep-ph]];
  %%CITATION = ARXIV:1011.5976;%%
  %64 citations counted in INSPIRE as of 26 May 2014
  W.~Bernreuther and Z.~-G.~Si,
  %``Distributions and correlations for top quark pair production and decay at the Tevatron and LHC.,''
  Nucl.\ Phys.\ B {\bf 837}, 90 (2010)  [arXiv:1003.3926 [hep-ph]];
  %%CITATION = ARXIV:1003.3926;%%
  %117 citations counted in INSPIRE as of 26 May 2014
  R.~Schwienhorst, C.~-P.~Yuan, C.~Mueller and Q.~-H.~Cao,
  %``Single top quark production and decay in the $t$-channel at next-to-leading order at the LHC,''
  Phys.\ Rev.\ D {\bf 83}, 034019 (2011)  [arXiv:1012.5132 [hep-ph]];
  %%CITATION = ARXIV:1012.5132;%%
  %30 citations counted in INSPIRE as of 26 May 2014
  J.~Shelton,
  %``Polarized tops from new physics: signals and observables,''
  Phys.\ Rev.\ D {\bf 79}, 014032 (2009)  [arXiv:0811.0569 [hep-ph]].
  %%CITATION = ARXIV:0811.0569;%%
  %35 citations counted in INSPIRE as of 26 May 2014


\bibitem{top_cp_review}
  D.~Atwood, S.~Bar-Shalom, G.~Eilam and A.~Soni,
  %``CP violation in top physics,''
  Phys.\ Rept.\  {\bf 347}, 1 (2001)  [hep-ph/0006032].
  %%CITATION = HEP-PH/0006032;%%
  %124 citations counted in INSPIRE as of 25 May 2014


\bibitem{zupan}
  J.~Brod, U.~Haisch and J.~Zupan,
  %``Constraints on CP-violating Higgs couplings to the third generation,''
  JHEP {\bf 1311}, 180 (2013)  [arXiv:1310.1385 [hep-ph], arXiv:1310.1385].
  %%CITATION = ARXIV:1310.1385;%%
  %11 citations counted in INSPIRE as of 25 May 2014


%\bibitem{Cheung:2013kla}
%  K.~Cheung, J.~S.~Lee and P.~Y.~Tseng,
%  %``Higgs Precision (Higgcision) Era begins,''
%  JHEP {\bf 1305} (2013) 134
%  [arXiv:1302.3794 [hep-ph]].
%  %%CITATION = ARXIV:1302.3794;%%
%  %57 citations counted in INSPIRE as of 25 Aug 2014

\bibitem{higgssignals}
  P.~Bechtle {\it et al.},
  %``$HiggsSignals$: Confronting arbitrary Higgs sectors with measurements at the Tevatron and the LHC,''
  Eur.\ Phys.\ J.\ C {\bf 74}, 2711 (2014)  [arXiv:1305.1933 [hep-ph]];
  %%CITATION = ARXIV:1305.1933;%%
  %33 citations counted in INSPIRE as of 23 Apr 2014
  P.~Bechtle {\it et al.},
  %``HiggsBounds: Confronting Arbitrary Higgs Sectors with Exclusion Bounds from LEP and the Tevatron,''
  Comput.\ Phys.\ Commun.\  {\bf 181}, 138 (2010)  [arXiv:0811.4169 [hep-ph]].
  %%CITATION = ARXIV:0811.4169;%%
  %161 citations counted in INSPIRE as of 23 Apr 2014

\bibitem{Maito_fit}
  H.~Belusca-Maito,
  %``Effective Higgs Lagrangian and Constraints on Higgs Couplings,''
  arXiv:1404.5343 [hep-ph].
  %%CITATION = ARXIV:1404.5343;%%
  %1 citations counted in INSPIRE as of 16 Jun 2014

\bibitem{Nishiwaki_fit}
  K.~Nishiwaki, S.~Niyogi and A.~Shivaji,
  %``$ttH$ Anomalous Coupling in Double Higgs Production,''
  JHEP {\bf 1404} (2014) 011
  [arXiv:1309.6907 [hep-ph]].
  %%CITATION = ARXIV:1309.6907;%%
  %6 citations counted in INSPIRE as of 16 Jun 2014


\bibitem{snowmass}
  S.~Dawson {\it et al.},
  %``Higgs Working Group Report of the Snowmass 2013 Community Planning Study,''
  arXiv:1310.8361 [hep-ex].
  %%CITATION = ARXIV:1310.8361;%%  %34 citations counted in INSPIRE as of 23 Apr 2014

\bibitem{pdg}
J. Beringer {\it et al.}, Particle Data Group, Phys.\ Rev. \ D {\bf 86}, 010001 (2012).


\bibitem{tth_bb}
ATLAS Collaboration [ATLAS Collaboration], ATLAS-CONF-2012-135;
CMS Collaboration [CMS Collaboration], CMS-PAS-HIG-12-025.

\bibitem{feynrules}
  A.~Alloul, N.~D.~Christensen, C.~Degrande, C.~Duhr and B.~Fuks,
  %``FeynRules 2.0 - A complete toolbox for tree-level phenomenology,''
  arXiv:1310.1921 [hep-ph].
  %%CITATION = ARXIV:1310.1921;%%
  %47 citations counted in INSPIRE as of 25 May 2014


\bibitem{mad5}
  J.~Alwall {\it et al.},
  %``MadGraph 5 : Going Beyond,''
  JHEP {\bf 1106}, 128 (2011).
  %%CITATION = ARXIV:1106.0522;%%

\bibitem{pythia}
  T.~Sjostrand, S.~Mrenna and P.~Z.~Skands,
  %``PYTHIA 6.4 Physics and Manual,''
  JHEP {\bf 0605}, 026 (2006).
  %%CITATION = HEP-PH/0603175;%%

\bibitem{delphes}
  J.~de Favereau,  {\it et al.},
  %``DELPHES 3, A modular framework for fast simulation of a generic collider experiment,''
arXiv:1307.6346 [hep-ex].


\bibitem{anti-kt}
  M.~Cacciari, G.~P.~Salam and G.~Soyez,
  %``The Anti-k(t) jet clustering algorithm,''
  JHEP {\bf 0804}, 063 (2008).
  %%CITATION = ARXIV:0802.1189;%%

\bibitem{cteq}  J.~Pumplin {\it et al.}, JHEP {\bf 0602}, 032 (2006).
                %%CITATION = HEP-PH 0512167;%

%\cite{Mangano:2006rw}
\bibitem{Mangano:2006rw}
  M.~L.~Mangano, M.~Moretti, F.~Piccinini and M.~Treccani,
  %``Matching matrix elements and shower evolution for top-quark production in hadronic collisions,''
  JHEP {\bf 0701} (2007) 013
  [hep-ph/0611129].
  %%CITATION = HEP-PH/0611129;%%
  %285 citations counted in INSPIRE as of 25 Aug 2014

\bibitem{cms-b}
CMS Collaboration, b-Jet Identification in the CMS Experiment, CMS-PAS-BTV-11-004.

\bibitem{qinghong}
  E.~L.~Berger, Q.~-H.~Cao, J.~-H.~Yu and C.~-P.~Yuan,
  %``Calculation of Associated Production of a Top Quark and a W' at the LHC,''
  Phys.\ Rev.\ D {\bf 84}, 095026 (2011)  [arXiv:1108.3613 [hep-ph]].
  %%CITATION = ARXIV:1108.3613;%%
  %14 citations counted in INSPIRE as of 26 May 2014


\end{thebibliography}

\end{document}

1406.1961.extracted_bib
{higgs-atlas G. Aad et al.(ATLAS Collaboration), Phys. Lett. B 710, 49 (2012).
1406.1961.extracted_bib
{higgs-cms S. Chatrachyan et al.(CMS Collaboration), Phys. Lett. B 710, 26 (2012).
1406.1961.extracted_bib
{review the recent reviews, see examples: S.~Dawson, A.~Gritsan, H.~Logan, J.~Qian, C.~Tully, R.~Van Kooten, A.~Ajaib and A.~Anastassov {et al., %``Working Group Report: Higgs Boson,'' arXiv:1310.8361 [hep-ex]; %%CITATION = ARXIV:1310.8361;%% %43 citations counted in INSPIRE as of 24 May 2014 C.~Englert, A.~Freitas, M.~Muhlleitner, T.~Plehn, M.~Rauch, M.~Spira and K.~Walz, %``Precision Measurements of Higgs Couplings: Implications for New Physics Scales,'' arXiv:1403.7191 [hep-ph]; %%CITATION = ARXIV:1403.7191;%% %5 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{hf see recent examples at the TLEP and ILC: V.~Barger, L.~L.~Everett, H.~E.~Logan and G.~Shaughnessy, %``Scrutinizing h(125) in Two Higgs Doublet Models at the LHC, ILC, and Muon Collider,'' P hys.\ Rev.\ D {88, 115003 (2013) [arXiv:1308.0052 [hep-ph]]; %%CITATION = ARXIV:1308.0052;%% %22 citations counted in INSPIRE as of 24 May 2014 A.~Kobakhidze and J.~Yue, %``Excluding a Generic Spin-2 Higgs Impostor,'' Phys.\ Lett.\ B {727, 456 (2013) [arXiv:1310.0151 [hep-ph]]; %%CITATION = ARXIV:1310.0151;%% %2 citations counted in INSPIRE as of 24 May 2014 N.~Liu, J.~Ren, L.~Wu, P.~Wu and J.~M.~Yang, %``Full one-loop electroweak corrections to $e^+e^- \to ZH\gamma$ at a Higgs factory,'' JHEP {1404, 189 (2014) [arXiv:1311.6971 [hep-ph]]; %%CITATION = ARXIV:1311.6971;%% %2 citations counted in INSPIRE as of 24 May 2014 Z.~Heng, L.~Shang and P.~Wan, %``Pair production of a 125 GeV Higgs boson in MSSM and NMSSM at the ILC,'' JHEP {1310, 047 (2013) [arXiv:1306.0279 [hep-ph]]; %%CITATION = ARXIV:1306.0279;%% %5 citations counted in INSPIRE as of 24 May 2014 S.~L.~Hu, N.~Liu, J.~Ren and L.~Wu, %``Probing Higgs couplings to diphoton and Z-photon from Higgs$+$photon production at a Higgs factory,'' arXiv:1402.3050 [hep-ph]; %%CITATION = ARXIV:1402.3050;%% L.~Wang and X.~-F.~Han, %``Study of the heavy CP-even Higgs with mass 125 GeV in two-Higgs-doublet models at the LHC and ILC,'' arXiv:1404.7437 [hep-ph]; %%CITATION = ARXIV:1404.7437;%% %1 citations counted in INSPIRE as of 24 May 2014 C.~Han, A.~Kobakhidze, N.~Liu, L.~Wu and B.~Yang, %``Constraining Top partner and Naturalness at the LHC and TLEP,'' arXiv:1405.1498 [hep-ph]; %%CITATION = ARXIV:1405.1498;%% J.~Cao, Z.~Heng, D.~Li, L.~Shang and P.~Wu, %``Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs factory in the Minimal Dilaton Model,'' arXiv:1405.4489 [hep-ph]; %%CITATION = ARXIV:1405.4489;%%
1406.1961.extracted_bib
{tth_old W.~J.~Marciano and F.~E.~Paige, %``Associated production of Higgs bosons with t anti-t pairs,'' Phys.\ Rev.\ Lett.\ {66, 2433 (1991); %%CITATION = PRLTA,66,2433;%% %137 citations counted in INSPIRE as of 24 May 2014 J.~Dai, J.~F.~Gunion and R.~Vega, %``Using b tagging to detect t anti-t Higgs production with Higgs ---> b anti-b,'' Phys.\ Rev.\ Lett.\ {71, 2699 (1993) [hep-ph/9306271]; %%CITATION = HEP-PH/9306271;%% %62 citations counted in INSPIRE as of 24 May 2014 J.~Goldstein, C.~S.~Hill, J.~Incandela, S.~J.~Parke, D.~L.~Rainwater and D.~Stuart, %``$p\bar{p\to t\bar{tH$: A Discovery mode for the Higgs boson at the Tevatron,'' Phys.\ Rev.\ Lett.\ {86, 1694 (2001) [hep-ph/0006311]; %%CITATION = HEP-PH/0006311;%% %55 citations counted in INSPIRE as of 24 May 2014 A.~Belyaev and L.~Reina, %``pp ---> t anti-t H, H ---> tau+ tau-: Toward a model independent determination of the Higgs boson couplings at the LHC,'' JHEP {0208, 041 (2002) [hep-ph/0205270]; %%CITATION = HEP-PH/0205270;%% %101 citations counted in INSPIRE as of 24 May 2014 F.~Maltoni, D.~L.~Rainwater and S.~Willenbrock, %``Measuring the top quark Yukawa coupling at hadron colliders via $t\bar{tH,H\to W^+W^-$,'' Phys.\ Rev.\ D {66, 034022 (2002) [hep-ph/0202205]; %%CITATION = HEP-PH/0202205;%% %62 citations counted in INSPIRE as of 24 May 2014 V.~Drollinger, T.~Muller and D.~Denegri, %``Searching for Higgs bosons in association with top quark pairs in the H0 ---> b anti-b decay mode,'' hep-ph/0111312; %%CITATION = HEP-PH/0111312;%% %87 citations counted in INSPIRE as of 24 May 2014 W.~Beenakker, S.~Dittmaier, M.~Kramer, B.~Plumper, M.~Spira and P.~M.~Zerwas, %``NLO QCD corrections to t anti-t H production in hadron collisions,'' Nucl.\ Phys.\ B {653, 151 (2003) [hep-ph/0211352]. %%CITATION = HEP-PH/0211352;%% %250 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{tth_new P.~Agrawal, S.~Bandyopadhyay and S.~P.~Das, %``Multilepton Signatures of the Higgs Boson through its Production in Association with a Top-quark Pair,'' Phys.\ Rev.\ D {88, 093008 (2013) [arXiv:1308.3043 [hep-ph]]; %%CITATION = ARXIV:1308.3043;%% %5 citations counted in INSPIRE as of 24 May 2014 S.~Biswas, R.~Frederix, E.~Gabrielli and B.~Mele, %``Enhancing the ttH signal through top-quark spin polarization effects at the LHC,'' arXiv:1403.1790 [hep-ph]; %%CITATION = ARXIV:1403.1790;%% M.~V.~Garzelli, A.~Kardos, C.~G.~Papadopoulos and Z.~Trocsanyi, %``Standard Model Higgs boson production in association with a top anti-top pair at NLO with parton showering,'' Europhys.\ Lett.\ {96, 11001 (2011) [arXiv:1108.0387 [hep-ph]]; %%CITATION = ARXIV:1108.0387;%% %34 citations counted in INSPIRE as of 24 May 2014 R.~Frederix, S.~Frixione, V.~Hirschi, F.~Maltoni, R.~Pittau and P.~Torrielli, %``Scalar and pseudoscalar Higgs production in association with a top-antitop pair,'' Phys.\ Lett.\ B {701, 427 (2011) [arXiv:1104.5613 [hep-ph]]; %%CITATION = ARXIV:1104.5613;%% %58 citations counted in INSPIRE as of 24 May 2014 C.~Degrande, J.~M.~Gerard, C.~Grojean, F.~Maltoni and G.~Servant, %``Probing Top-Higgs Non-Standard Interactions at the LHC,'' JHEP {1207, 036 (2012) [Erratum-ibid.\ {1303, 032 (2013)] [arXiv:1205.1065 [hep-ph]]; %%CITATION = ARXIV:1205.1065;%% %25 citations counted in INSPIRE as of 24 May 2014 D.~Curtin, J.~Galloway and J.~G.~Wacker, %``Measuring the tth coupling from SSDL+2b measurements,'' Phys.\ Rev.\ D {88, 093006 (2013) [arXiv:1306.5695 [hep-ph]]; %%CITATION = ARXIV:1306.5695;%% %11 citations counted in INSPIRE as of 24 May 2014 J.~Adelman, A.~Loginov, P.~Tipton and J.~Vasquez, %``Study of $t\bar{tH$ ($H \to \mu^+ \bar{\mu^-$) in the three lepton channel at $\sqrt{s=14$ TeV; A Snowmass white paper,'' arXiv:1310.1132 [hep-ex]; %%CITATION = ARXIV:1310.1132;%% %3 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{atlas_tth ATLAS Collaboration [ATLAS Collaboration], ATLAS-CONF-2014-011.
1406.1961.extracted_bib
{ttj CMS Collaboration [CMS Collaboration], %``First Measurement of the cross section ratio ttbb/ttjj in pp Collisions at sqrt{s,'' CMS-PAS-TOP-12-024. %%CITATION = CMS-PAS-TOP-12-024;%% %14 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{thj_old G.~Bordes and B.~van Eijk, %``On the associate production of a neutral intermediate mass Higgs boson with a single top quark at the LHC and SSC,'' Phys.\ Lett.\ B {299, 315 (1993); %%CITATION = PHLTA,B299,315;%% %15 citations counted in INSPIRE as of 24 May 2014 A.~Ballestrero and E.~Maina, %``t anti-b H production for an intermediate mass Higgs,'' Phys.\ Lett.\ B {299, 312 (1993); %%CITATION = PHLTA,B299,312;%% %16 citations counted in INSPIRE as of 24 May 2014 W.~J.~Stirling and D.~J.~Summers, %``Production of an intermediate mass Higgs boson in association with a single top quark at LHC and SSC,'' Phys.\ Lett.\ B {283, 411 (1992); %%CITATION = PHLTA,B283,411;%% %19 citations counted in INSPIRE as of 24 May 2014 J.~L.~Diaz-Cruz and O.~A.~Sampayo, %``Associated production of the Higgs boson with t anti-b at hadron colliders,'' Phys.\ Lett.\ B {276, 211 (1992). %%CITATION = PHLTA,B276,211;%% %10 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{maltoni_thj1 F.~Maltoni, K.~Paul, T.~Stelzer and S.~Willenbrock, %``Associated production of Higgs and single top at hadron colliders,'' Phys.\ Rev.\ D {64, 094023 (2001) [hep-ph/0106293]. %%CITATION = HEP-PH/0106293;%% %35 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{maltoni_thj2 M.~Farina, C.~Grojean, F.~Maltoni, E.~Salvioni and A.~Thamm, %``Lifting degeneracies in Higgs couplings using single top production in association with a Higgs boson,'' JHEP {1305, 022 (2013) [arXiv:1211.3736 [hep-ph]]. %%CITATION = ARXIV:1211.3736;%% %32 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{biswas_thj S.~Biswas, E.~Gabrielli and B.~Mele, %``Single top and Higgs associated production as a probe of the Htt coupling sign at the LHC,'' JHEP {1301, 088 (2013) [arXiv:1211.0499 [hep-ph]]. %%CITATION = ARXIV:1211.0499;%% %26 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{ellis_thj J.~Ellis, D.~S.~Hwang, K.~Sakurai and M.~Takeuchi, %``Disentangling Higgs-Top Couplings in Associated Production,'' JHEP {1404, 004 (2014) [arXiv:1312.5736 [hep-ph]]. %%CITATION = ARXIV:1312.5736;%% %9 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{englert C.~Englert and E.~Re, %``Bounding the top Yukawa with Higgs-associated single-top production,'' Phys.\ Rev.\ D {89, 073020 (2014) [arXiv:1402.0445 [hep-ph]]; %%CITATION = ARXIV:1402.0445;%% %3 citations counted in INSPIRE as of 26 May 2014
1406.1961.extracted_bib
{lee_thj J.~Chang, K.~Cheung, J.~S.~Lee and C.~-T.~Lu, %``Probing the Top-Yukawa Coupling in Associated Higgs production with a Single Top Quark,'' JHEP {1405, 062 (2014) [arXiv:1403.2053 [hep-ph]]; %%CITATION = ARXIV:1403.2053;%% %1 citations counted in INSPIRE as of 24 May 2014
1406.1961.extracted_bib
{eff J.~A.~Aguilar-Saavedra, %``A Minimal set of top-Higgs anomalous couplings,'' Nucl.\ Phys.\ B {821, 215 (2009) [arXiv:0904.2387 [hep-ph]]; %%CITATION = ARXIV:0904.2387;%% %57 citations counted in INSPIRE as of 25 May 2014 C.~Zhang, N.~Greiner and S.~Willenbrock, %``Constraints on Non-standard Top Quark Couplings,'' Phys.\ Rev.\ D {86 (2012) 014024 [arXiv:1201.6670 [hep-ph]]; %%CITATION = ARXIV:1201.6670;%% %24 citations counted in INSPIRE as of 27 May 2014 X.~Zhang, S.~K.~Lee, K.~Whisnant and B.~L.~Young, %``Phenomenology of a nonstandard top quark Yukawa coupling,'' Phys.\ Rev.\ D {50 (1994) 7042 [hep-ph/9407259]; %%CITATION = HEP-PH/9407259;%% P.~Agrawal, S.~Mitra and A.~Shivaji, %``Effect of Anomalous Couplings on the Associated Production of a Single Top Quark and a Higgs Boson at the LHC,'' JHEP {1312 (2013) 077 [arXiv:1211.4362 [hep-ph]]; %%CITATION = ARXIV:1211.4362;%% %9 citations counted in INSPIRE as of 16 Jun 2014 Y.~Wang, F.~P.~Huang, C.~S.~Li, B.~H.~Li, D.~Y.~Shao and J.~Wang, %``Constraints on flavor-changing neutral-current $Htq$ couplings from the signal of $tH$ associated production with QCD next-to-leading order accuracy at the LHC,'' Phys.\ Rev.\ D {86 (2012) 094014 [arXiv:1208.2902 [hep-ph]]; %%CITATION = ARXIV:1208.2902;%% %4 citations counted in INSPIRE as of 16 Jun 2014 G.~Bhattacharyya, D.~Das and P.~B.~Pal, %``Modified Higgs couplings and unitarity violation,'' Phys.\ Rev.\ D {87 (2013) 011702 [arXiv:1212.4651 [hep-ph]]. %%CITATION = ARXIV:1212.4651;%% %9 citations counted in INSPIRE as of 28 Aug 2014
1406.1961.extracted_bib
{cpv_model1 A.~Djouadi, %``The Anatomy of electro-weak symmetry breaking. II. The Higgs bosons in the minimal supersymmetric model,'' Phys.\ Rept.\ {459, 1 (2008) [hep-ph/0503173]; %%CITATION = HEP-PH/0503173;%% %685 citations counted in INSPIRE as of 25 May 2014 A.~Djouadi and G.~Moreau, %``The couplings of the Higgs boson and its CP properties from fits of the signal strengths and their ratios at the 7+8 TeV LHC,'' arXiv:1303.6591 [hep-ph]. %%CITATION = ARXIV:1303.6591;%% %80 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{cpv_model2 D.~McKeen, M.~Pospelov and A.~Ritz, %``Modified Higgs branching ratios versus CP and lepton flavor violation,'' Phys.\ Rev.\ D {86, 113004 (2012) [arXiv:1208.4597 [hep-ph]]; %%CITATION = ARXIV:1208.4597;%% %35 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{cpv_model3 A.~Celis, V.~Ilisie and A.~Pich, %``LHC constraints on two-Higgs doublet models,'' JHEP {1307, 053 (2013) [arXiv:1302.4022 [hep-ph]]; %%CITATION = ARXIV:1302.4022;%% %61 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{cpv_model4 J.~Shu and Y.~Zhang, %``Impact of a CP Violating Higgs Sector: From LHC to Baryogenesis,'' Phys.\ Rev.\ Lett.\ {111, no. 9, 091801 (2013) [arXiv:1304.0773 [hep-ph]]. %%CITATION = ARXIV:1304.0773;%% %24 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{archil A.~Kobakhidze, %``Standard Model with a distorted Higgs sector and the enhanced Higgs diphoton decay rate,'' arXiv:1208.5180 [hep-ph]. %%CITATION = ARXIV:1208.5180;%% %13 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{cms_thj CMS Collaboration [CMS Collaboration], CMS-PAS-HIG-14-001.
1406.1961.extracted_bib
{top_pol see recent examples: A.~Prasath, R.~M.~Godbole and S.~D.~Rindani, %``Top polarisation measurement and anomalous $Wtb$ coupling,'' arXiv:1405.1264 [hep-ph]; %%CITATION = ARXIV:1405.1264;%% %1 citations counted in INSPIRE as of 25 May 2014 J.~A.~Aguilar-Saavedra and S.~A.~dos Santos, %``New directions for top quark polarization in the $t$-channel process,'' arXiv:1404.1585 [hep-ph]; %%CITATION = ARXIV:1404.1585;%% %1 citations counted in INSPIRE as of 26 May 2014 S.~Biswas, R.~Frederix, E.~Gabrielli and B.~Mele, %``Enhancing the ttH signal through top-quark spin polarization effects at the LHC,'' arXiv:1403.1790 [hep-ph]; %%CITATION = ARXIV:1403.1790;%% W.~Bernreuther and Z.~-G.~Si, %``Top quark spin correlations and polarization at the LHC: standard model predictions and effects of anomalous top chromo moments,'' Phys.\ Lett.\ B {725, 1-3, 115 (2013) [arXiv:1305.2066 [hep-ph]]; %%CITATION = ARXIV:1305.2066;%% %9 citations counted in INSPIRE as of 26 May 2014 Q.~-H.~Cao, X.~Wan, X.~-p.~Wang and S.~-h.~Zhu, %``Searching for Charged Higgs Boson in Polarized Top Quark,'' Phys.\ Rev.\ D {87, 5, 055022 (2013) [arXiv:1301.6608 [hep-ph]]; %%CITATION = ARXIV:1301.6608;%% %4 citations counted in INSPIRE as of 26 May 2014 B.~Yang and N.~Liu, %``One-loop effects on top pair production in the littlest Higgs model with T-parity at the LHC,'' arXiv:1210.5120 [hep-ph]; %%CITATION = ARXIV:1210.5120;%% %3 citations counted in INSPIRE as of 25 May 2014 J.~A.~Aguilar-Saavedra and R.~V.~Herrero-Hahn, %``Model-independent measurement of the top quark polarisation,'' Phys.\ Lett.\ B {718, 983 (2013) [arXiv:1208.6006 [hep-ph]]; %%CITATION = ARXIV:1208.6006;%% %6 citations counted in INSPIRE as of 25 May 2014 X.~-Q.~Li, Z.~-G.~Si, K.~Wang, L.~Wang, L.~Zhang and G.~Zhu, %``Light Top Squark in Precision Top Quark Sample,'' Phys.\ Rev.\ D {89, 077703 (2014) [arXiv:1311.6874 [hep-ph]]; %%CITATION = ARXIV:1311.6874;%% %4 citations counted in INSPIRE as of 06 Jun 2014 I.~Low, %``Polarized Charginos (and Tops) in Stop Decays,'' Phys.\ Rev.\ D {88 (2013) 095018 [arXiv:1304.0491 [hep-ph]]; %%CITATION = ARXIV:1304.0491;%% %8 citations counted in INSPIRE as of 05 Jun 2014 R.~M.~Godbole, L.~Hartgring, I.~Niessen and C.~D.~White, %``Top polarisation studies in $H^-t$ and $Wt$ production,'' JHEP {1201, 011 (2012) [arXiv:1111.0759 [hep-ph]]; %%CITATION = ARXIV:1111.0759;%% %14 citations counted in INSPIRE as of 25 May 2014 J.~Cao, K.~Hikasa, L.~Wang, L.~Wu and J.~M.~Yang, %``Testing new physics models by top charge asymmetry and polarization at the LHC,'' Phys.\ Rev.\ D {85, 014025 (2012) [arXiv:1109.6543 [hep-ph]]; %%CITATION = ARXIV:1109.6543;%% %27 citations counted in INSPIRE as of 25 May 2014 D.~Krohn, T.~Liu, J.~Shelton and L.~-T.~Wang, %``A Polarized View of the Top Asymmetry,'' Phys.\ Rev.\ D {84, 074034 (2011) [arXiv:1105.3743 [hep-ph]]; %%CITATION = ARXIV:1105.3743;%% %74 citations counted in INSPIRE as of 26 May 2014 J.~Cao, L.~Wu and J.~M.~Yang, %``New physics effects on top quark spin correlation and polarization at the LHC: a comparative study in different models,'' Phys.\ Rev.\ D {83, 034024 (2011) [arXiv:1011.5564 [hep-ph]]; %%CITATION = ARXIV:1011.5564;%% %46 citations counted in INSPIRE as of 25 May 2014 D.~Choudhury, R.~M.~Godbole, S.~D.~Rindani and P.~Saha, %``Top polarization, forward-backward asymmetry and new physics,'' Phys.\ Rev.\ D {84, 014023 (2011) [arXiv:1012.4750 [hep-ph]]. %%CITATION = ARXIV:1012.4750;%% %69 citations counted in INSPIRE as of 26 May 2014 D.~-W.~Jung, P.~Ko and J.~S.~Lee, %``Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron,'' Phys.\ Lett.\ B {701, 248 (2011) [arXiv:1011.5976 [hep-ph]]; %%CITATION = ARXIV:1011.5976;%% %64 citations counted in INSPIRE as of 26 May 2014 W.~Bernreuther and Z.~-G.~Si, %``Distributions and correlations for top quark pair production and decay at the Tevatron and LHC.,'' Nucl.\ Phys.\ B {837, 90 (2010) [arXiv:1003.3926 [hep-ph]]; %%CITATION = ARXIV:1003.3926;%% %117 citations counted in INSPIRE as of 26 May 2014 R.~Schwienhorst, C.~-P.~Yuan, C.~Mueller and Q.~-H.~Cao, %``Single top quark production and decay in the $t$-channel at next-to-leading order at the LHC,'' Phys.\ Rev.\ D {83, 034019 (2011) [arXiv:1012.5132 [hep-ph]]; %%CITATION = ARXIV:1012.5132;%% %30 citations counted in INSPIRE as of 26 May 2014 J.~Shelton, %``Polarized tops from new physics: signals and observables,'' Phys.\ Rev.\ D {79, 014032 (2009) [arXiv:0811.0569 [hep-ph]]. %%CITATION = ARXIV:0811.0569;%% %35 citations counted in INSPIRE as of 26 May 2014
1406.1961.extracted_bib
{top_cp_review D.~Atwood, S.~Bar-Shalom, G.~Eilam and A.~Soni, %``CP violation in top physics,'' Phys.\ Rept.\ {347, 1 (2001) [hep-ph/0006032]. %%CITATION = HEP-PH/0006032;%% %124 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{zupan J.~Brod, U.~Haisch and J.~Zupan, %``Constraints on CP-violating Higgs couplings to the third generation,'' JHEP {1311, 180 (2013) [arXiv:1310.1385 [hep-ph], arXiv:1310.1385]. %%CITATION = ARXIV:1310.1385;%% %11 citations counted in INSPIRE as of 25 May 2014 %
1406.1961.extracted_bib
{Cheung:2013kla % K.~Cheung, J.~S.~Lee and P.~Y.~Tseng, % %``Higgs Precision (Higgcision) Era begins,'' % JHEP {1305 (2013) 134 % [arXiv:1302.3794 [hep-ph]]. % %%CITATION = ARXIV:1302.3794;%% % %57 citations counted in INSPIRE as of 25 Aug 2014
1406.1961.extracted_bib
{higgssignals P.~Bechtle {et al., %``$HiggsSignals$: Confronting arbitrary Higgs sectors with measurements at the Tevatron and the LHC,'' Eur.\ Phys.\ J.\ C {74, 2711 (2014) [arXiv:1305.1933 [hep-ph]]; %%CITATION = ARXIV:1305.1933;%% %33 citations counted in INSPIRE as of 23 Apr 2014 P.~Bechtle {et al., %``HiggsBounds: Confronting Arbitrary Higgs Sectors with Exclusion Bounds from LEP and the Tevatron,'' Comput.\ Phys.\ Commun.\ {181, 138 (2010) [arXiv:0811.4169 [hep-ph]]. %%CITATION = ARXIV:0811.4169;%% %161 citations counted in INSPIRE as of 23 Apr 2014
1406.1961.extracted_bib
{Maito_fit H.~Belusca-Maito, %``Effective Higgs Lagrangian and Constraints on Higgs Couplings,'' arXiv:1404.5343 [hep-ph]. %%CITATION = ARXIV:1404.5343;%% %1 citations counted in INSPIRE as of 16 Jun 2014
1406.1961.extracted_bib
{Nishiwaki_fit K.~Nishiwaki, S.~Niyogi and A.~Shivaji, %``$ttH$ Anomalous Coupling in Double Higgs Production,'' JHEP {1404 (2014) 011 [arXiv:1309.6907 [hep-ph]]. %%CITATION = ARXIV:1309.6907;%% %6 citations counted in INSPIRE as of 16 Jun 2014
1406.1961.extracted_bib
{snowmass S.~Dawson {et al., %``Higgs Working Group Report of the Snowmass 2013 Community Planning Study,'' arXiv:1310.8361 [hep-ex]. %%CITATION = ARXIV:1310.8361;%% %34 citations counted in INSPIRE as of 23 Apr 2014
1406.1961.extracted_bib
{pdg J. Beringer {et al., Particle Data Group, Phys.\ Rev. \ D {86, 010001 (2012).
1406.1961.extracted_bib
{tth_bb ATLAS Collaboration [ATLAS Collaboration], ATLAS-CONF-2012-135; CMS Collaboration [CMS Collaboration], CMS-PAS-HIG-12-025.
1406.1961.extracted_bib
{feynrules A.~Alloul, N.~D.~Christensen, C.~Degrande, C.~Duhr and B.~Fuks, %``FeynRules 2.0 - A complete toolbox for tree-level phenomenology,'' arXiv:1310.1921 [hep-ph]. %%CITATION = ARXIV:1310.1921;%% %47 citations counted in INSPIRE as of 25 May 2014
1406.1961.extracted_bib
{mad5 J.~Alwall {et al., %``MadGraph 5 : Going Beyond,'' JHEP {1106, 128 (2011). %%CITATION = ARXIV:1106.0522;%%
1406.1961.extracted_bib
{pythia T.~Sjostrand, S.~Mrenna and P.~Z.~Skands, %``PYTHIA 6.4 Physics and Manual,'' JHEP {0605, 026 (2006). %%CITATION = HEP-PH/0603175;%%
1406.1961.extracted_bib
{delphes J.~de Favereau, {et al., %``DELPHES 3, A modular framework for fast simulation of a generic collider experiment,'' arXiv:1307.6346 [hep-ex].
1406.1961.extracted_bib
{anti-kt M.~Cacciari, G.~P.~Salam and G.~Soyez, %``The Anti-k(t) jet clustering algorithm,'' JHEP {0804, 063 (2008). %%CITATION = ARXIV:0802.1189;%%
1406.1961.extracted_bib
{cteq J.~Pumplin {et al., JHEP {0602, 032 (2006). %%CITATION = HEP-PH 0512167;% %\cite{Mangano:2006rw
1406.1961.extracted_bib
{Mangano:2006rw M.~L.~Mangano, M.~Moretti, F.~Piccinini and M.~Treccani, %``Matching matrix elements and shower evolution for top-quark production in hadronic collisions,'' JHEP {0701 (2007) 013 [hep-ph/0611129]. %%CITATION = HEP-PH/0611129;%% %285 citations counted in INSPIRE as of 25 Aug 2014
1406.1961.extracted_bib
{cms-b CMS Collaboration, b-Jet Identification in the CMS Experiment, CMS-PAS-BTV-11-004.
1406.1961.extracted_bib
{qinghong E.~L.~Berger, Q.~-H.~Cao, J.~-H.~Yu and C.~-P.~Yuan, %``Calculation of Associated Production of a Top Quark and a W' at the LHC,'' Phys.\ Rev.\ D {84, 095026 (2011) [arXiv:1108.3613 [hep-ph]]. %%CITATION = ARXIV:1108.3613;%% %14 citations counted in INSPIRE as of 26 May 2014