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\documentclass[fleqn,twoside]{article}

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\usepackage[headings]{espcrc2}
\usepackage[tbtags]{amsmath}
\usepackage{amssymb,bm}
\mathindent=0pt
% if you want to include PostScript figures
\usepackage{graphicx}
% if you have landscape tables
\usepackage[figuresright]{rotating}
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\usepackage{color}

% identification
\readRCS
$Id: espcrc2.tex,v 1.2 2004/02/24 11:22:11 spepping Exp $
\ProvidesFile{espcrc2.tex}[\filedate \space v\fileversion
     \space Elsevier 2-column CRC Author Instructions]

%%%%%%%%%%%%%%%%%%%
%%%% Definitions
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% colours
\definecolor{red}{rgb}{1,0,0}

% states, particles, decays
\newcommand{\btoc}{\ensuremath{b\to c}}
\newcommand{\btos}{\ensuremath{b\to s}}

\newcommand{\ccs}{\ensuremath{c \overline{c} s}}
\newcommand{\btoccs}{\ensuremath{b\to \ccs}}
\newcommand{\ccd}{\ensuremath{c \overline{c} d}}
\newcommand{\btoccd}{\ensuremath{b\to \ccd}}
\newcommand{\sqq}{\ensuremath{s \overline{q} q}}
\newcommand{\btosqq}{\ensuremath{b\to \sqq}}
\newcommand{\sss}{\ensuremath{s \overline{s} s}}
\newcommand{\btosss}{\ensuremath{b\to \sss}}

\newcommand{\Bz}{\ensuremath{B^0}}
\newcommand{\Bzbar}{\ensuremath{\overline{B}{}^0}}
\newcommand{\UFS}{\ensuremath{\Upsilon(4\mathrm{S})}}
\newcommand{\BB}{\ensuremath{B\overline{B}}}
\newcommand{\fcp}{\ensuremath{f_{CP}}}
\newcommand{\ftag}{\ensuremath{f_\mathrm{tag}}}

% variables, quantities
\newcommand{\CP}{\ensuremath{CP}}
\newcommand{\sbeta}{\ensuremath{\sin 2\beta}}
\newcommand{\sphione}{\ensuremath{\sin 2\phi_1}}
\newcommand{\sphioneeff}{\ensuremath{\sin 2\phi_1^\mathrm{eff}}}
\newcommand{\vckm}{\ensuremath{V_{CKM}}}
\newcommand{\vud}{\ensuremath{V_{ud}}}
\newcommand{\vub}{\ensuremath{V_{ub}}}
\newcommand{\vubstar}{\ensuremath{V_{ub}{}^*}}
\newcommand{\vcd}{\ensuremath{V_{cd}}}
\newcommand{\vcb}{\ensuremath{V_{cb}}}
\newcommand{\vcbstar}{\ensuremath{V_{cb}{}^*}}
\newcommand{\vtd}{\ensuremath{V_{td}}}
\newcommand{\vtbstar}{\ensuremath{V_{tb}{}^*}}
\newcommand{\amp}{\ensuremath{\mathcal{A}}}
\newcommand{\ampbar}{\ensuremath{\overline{\mathcal{A}}}}
\newcommand{\ACP}{\ensuremath{A_{CP}}}
\newcommand{\Sfcp}{\ensuremath{S_{f_{CP}}}}
\newcommand{\Afcp}{\ensuremath{A_{f_{CP}}}}


% journals
\def\nima#1#2#3{ Nucl.\ Instr.\ and Meth.\   A \textbf{#1}, #3 (#2)}
\def\prl#1#2#3{ Phys.\ Rev.\ Lett.\            \textbf{#1}, #3 (#2)}
\def\prd#1#2#3{ Phys.\ Rev.\                 D \textbf{#1}, #3 (#2)}
\def\pthp#1#2#3{ Prog.\ Theor.\ Phys.\         \textbf{#1}, #3 (#2)}
\def\plb#1#2#3{ Phys.\ Lett.\                B \textbf{#1}, #3 (#2)}
\def\epjc#1#2#3{ Eur.\ Phys.\ J.\            C \textbf{#1}, #3 (#2)}
\def\hepex#1{ \texttt{hep-ex/#1}}

% others
\usepackage{relsize} % provides \smaller
\def\babarsym{\mbox{\slshape B\kern-0.1em{\smaller A}\kern-0.1em
    B\kern-0.1em{\smaller A\kern-0.2em R}}}

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\hyphenation{author another created financial paper re-commend-ed
             Post-Script}

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% Declarations for front matter
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\title{Measurements of \sphione/\sbeta\ in \btoc\ and \btos\ Decays
       at B-Factories}

\author{%
  Marko Bra\v{c}ko
  \address[UniMB]{University of Maribor, 
                  Smetanova ulica 17, SI-2000 Maribor, Slovenia}
  $^{\!\! , \!\!}$
  \address[JSI]{Jo\v{z}ef Stefan Institute, 
                P.O.B. 3000, SI-1001 Ljubljana, Slovenia}
  $^{\!\! , \!\!}$
  \thanks{On behalf of Belle and \babarsym\ collaborations.}
}

% If you use the option headings, 
% the title is also used as the running title, 
% and the authors are also used as the running authors.
% You can change that by using \runtitle and \runauthor.
\runtitle{B-Factories: \sphione/\sbeta\ from \btoc\ and \btos\ Decays}
\runauthor{M. Bra\v{c}ko}

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% End of declarations for front matter
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\begin{document}

\begin{abstract}
Measurements of time-dependent CP asymmetries related to the
extraction of the CKM-matrix parameter $\phi_1$/$\beta$ are
presented. Reported analyses, based on studies of neutral 
$B$-meson decays that proceed via \btoc\ and \btos\ processes, were
performed by Belle and \babarsym\ collaborations.

\vspace{1pc}
\end{abstract}

% typeset front matter (including abstract)
\maketitle

% Reset footnote counter after the front matter
\setcounter{footnote}{0}

\section{Introduction}
The Cabibbo-Kobayashi-Maskawa (CKM) picture~\cite{ref:CKM} of quark
transitions in the Standard Model (SM) introduces a unitary 3$\times$3
matrix, \vckm , whose related matrix elements can be expressed by
three real parameters and one irreducible complex phase. In
particular, unitarity condition applied to the product of first and
third columns of \vckm\ yields the relation \vud \vubstar+\vcd
\vcbstar + \vtd \vtbstar = 0, represented in the complex plane as the
so-called ``Unitarity Triangle'' (UT), with angles $\phi_1$, $\phi_2$
and $\phi_3$ (or $\beta$, $\alpha$ and $\gamma$,
respectively)\footnote{Both conventions are used equivalently in this
report.}. The non-vanishing phase in the \vckm\ results in a non-zero
area of the triangle -- and allows for the \CP\ violation in the SM.

The CKM angles can be measured by analysing \Bz\ and \Bzbar\ decays
into common \CP\ eigenstates, \fcp. These decays can occur directly,
\Bz$\to$\fcp, or through mixing, \Bz$\to$\Bzbar$\to$\fcp.\footnote{%
Charge-conjugated modes are implied throughout this report, unless
explicitly stated otherwise.} The interference of the two processes
leads to a difference between the \Bz\ and \Bzbar\ decay rates, which
can be observed as a time-dependent $CP$ asymmetry:
%%%%%%%%%%%%%%%%%%%%%
\begin{equation}
  \begin{split}
    \ACP (t) 
    &= \frac{\Gamma(\Bzbar \to \fcp; t) \! - \! \Gamma( \Bz \to \fcp; t) }
            {\Gamma(\Bzbar \to \fcp; t) \! + \! \Gamma( \Bz \to \fcp; t) } \\
    &= \Sfcp \sin \Delta m t + \Afcp \cos \Delta m t \, .
  \end{split}
  \label{eq:acp_def} 
\end{equation}
%%%%%%%%%%%%%%%%%%%%%
Here, $\Delta m$ is the mass difference\footnote{Quantities are
expressed in natural units, $\hbar = c = 1$.} between neutral $B$ mass
eigenstates, and the \CP\ coefficients,\footnote{Another convention,
$C_{\fcp}$= - \Afcp, is also used.}
%%%%%%%%%%%%%%%%%%%%%
\begin{equation*}
  \Sfcp=\frac{2 \; \Im (\lambda_{\fcp})}{1+|\lambda_{\fcp}|^2}  
  \ \ \mathrm{and} \ \
  \Afcp=\frac{1-|\lambda_{\fcp}|^2}{1+|\lambda_{\fcp}|^2} \, ,
\label{eq:cpv_coeff} 
\end{equation*}
%%%%%%%%%%%%%%%%%%%%%
are functions of the complex parameter $\lambda_{\fcp}= \frac{q}{p}
\frac{\amp(\Bzbar \to \fcp)}{\amp(\Bz \to \fcp)}$, depending on the
ratio of \Bz (\Bzbar) decay amplitudes $\amp(\Bz \to \fcp)$
($\amp(\Bzbar \to \fcp)$), and coefficients $q$ and $p$ connecting the
flavour and the mass eigenstates of the neutral $B$ mesons.  In the
SM, $|q/p| \simeq 1$ and $\lambda_{\fcp}$ thus equals approximately to
the ratio of \Bz\ and \Bzbar\ decay amplitudes. If these amplitudes
contain only one weak phase $\theta$, this means $\lambda_{\fcp}=
\xi_{\fcp} e^{2i\theta}$, where $\xi_{fcp} = \pm 1$ is the \CP\
eigenvalue of the final state \fcp. In decays where this weak phase is
$\phi_1$$(=$$\beta)$$\equiv$$\mathrm{arg} \left[- \vtd \vtbstar / \vcd
\vcbstar \right]$, the coefficient \Sfcp\ is related to \sphione\ and
the cosine term in Eq. \eqref{eq:acp_def} is expected to vanish: 
\Afcp=0.

\section{Experimental Set-up and Techniques}
Reported measurements were enabled by two successfully operating $e^+
e^-$ colliders (so-called \emph{B-factories}) -- KEKB in Japan and
PEP-II in the USA -- and two detectors, Belle~\cite{ref:Belle} and
\babarsym~\cite{ref:Babar}. Both colliders operate at the energy of
the \UFS\ resonance, slightly above the \BB-production threshold, and
the two detectors together have so far accumulated over $1 \times 10^{9}$
\BB\ pairs -- half of these are \Bz\Bzbar . Unless stated otherwise,
results from Belle (\babarsym ) are obtained on a sample of about 386
(227) million \BB\ pairs.  

Time-dependent $CP$ violation measurements exploit a decay chain \UFS
$\to$ \Bz\Bzbar $\to$ \fcp\ftag, where one of the neutral $B$ mesons
decays at time $t_{CP}$ to a final state \fcp , and the other ``starts
the measurement's clock'' when it decays at time $t_\mathrm{tag}$ to a
final state \ftag , distinguishing between \Bz\ and \Bzbar. Since the
\UFS\ resonance is produced with a Lorentz-boost factor of $\beta
\gamma = 0.425$ (0.55) for KEKB (PEP-II) along the beam axis ($z$) due
to asymmetric energies of $e^+$ and $e^-$ beams, and \Bz\Bzbar\ pairs
are almost at rest in the \UFS\ rest frame, the distance between the
$B$-meson decay vertices, $\Delta z = z_{CP} - z_\mathrm{tag}$, can be
converted to the difference of proper decay times: $\Delta t = t_{CP}
- t_\mathrm{tag} \approx \Delta z / (\beta \gamma)$. \Sfcp\ and \Afcp\
are obtained for each mode by fitting the observed $\Delta t$
distributions of \Bz\ and \Bzbar\ tagged samples.

\section{The angle $\bm{\phi_1/\beta}$ from $\bm{\btoccs}$ decays}
The decay modes, dominated by a tree-level $b$$\to$\ccs\ diagram, are
often referred to as the ``golden'' modes, since the dominant
tree-level diagram and the largest penguin contribution have the same
weak phase, while the largest penguin diagram with another weak phase
is doubly Cabbibo suppressed. The $b$$\to$\ccs\ \CP-violation
parameters are thus given by $A_{\ccs}$$=$$0$ and
$S_{\ccs}$$=$$-\xi_{\fcp} \sphione$, to an excellent precision.

Experimentally most favourable decay modes of this type, $\Bz \to
J/\psi K_S^0$ ($J/\psi K_L^0$) with $\xi_{\fcp} = -1$($+1$), are used
by the Belle collaboration for the latest
update~\cite{ref:btoccs_belle}. The \babarsym\ analysis~
\cite{ref:btoccs_babar} uses also $\psi(2S)K^0_S$, $\chi_{c1}K^0_S$,
$\eta_c K^0_S$ and $J/\psi K^{*0}(K^{*0}$$\to$ $K_S^0 \pi^0)$ final
states.  The asymmetry between the $\Delta t$ distributions for \Bz\
and \Bzbar\ tagged events is displayed in
Fig. \ref{fig:btoccs_results}, clearly establishing the $CP$ violation
for $B$ mesons. The results for $S_{\ccs}$$=\sphione$$(=\sbeta)$ are
given in the table shown in Fig.~\ref{fig:btoccs_averages}, together
with the average provided by the HFAG group \cite{ref:HFAG}. The
average value for the direct \CP\ asymmetry in \ccs\ modes is found to
be consistent with 0: $A_{\ccs}$$(=$$-C_{\ccs})$$=$$0.027 \pm 0.028$.

The World Average value for \sphione$= 0.687\pm 0.032$,
practically dominated by the results from the B-factories, can be
compared with the indirect constraints on the UT~\cite{ref:CKMfitter},
based on average values for $\varepsilon_K$, $|\vub/\vcb|$, $B_d$
and $B_s$ mixing, as illustrated in Fig.~\ref{fig:btoccs_averages}.
Good agreement of direct \sphione/\sbeta\ measurements with 
an indirect constraint, $({\sphione})_\mathrm{indirect} = 0.752^{+
  0.057}_{- 0.035}$, is a strong confirmation of the CKM mechanism.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[!t]
  \unitlength1.0in
  \centerline{%
    %%%% Figures 
    \begin{tabular}{c c}
      \includegraphics[width=0.22\textwidth]
                      {./plots/btoccs_belle_result.eps}
      & 
      \includegraphics[width=0.21\textwidth, height=0.26\textwidth]
                      {./plots/btoccs_babar_result.eps}
    \end{tabular}
    %%%% Labels and text
    \put(-2.68,0.45){\small{\sf\shortstack[c]
        {Belle}}}
    \put(-1.9,0.45){\small{\sf\shortstack[c]
        {A)}}}
    \put(-1.9,-0.06){\small{\sf\shortstack[c]
        {B)}}}
    \put(-0.47,0.6){\small{\sf\shortstack[c]
        {\babarsym}}}
    \put(-0.55,0.1){\tiny{\sf\shortstack[c]
        {\textcolor{red}{$CP$ odd}}}}
    \put(-0.55,-0.42){\tiny{\sf\shortstack[c]
        {\textcolor{red}{$CP$ even}}}}
     \put(-0.77,-0.82){\tiny{\sf\shortstack[c]
         {$\Delta t$(ps)}}}
  }
  \caption{
    $\Delta t$ distributions (A, a and c) and raw asymmetries (B, b
    and d) in \btoccs\ decays at the Belle (left) and the \babarsym\
    (right) experiments. For Belle plots, $CP$-odd ($\xi_{\fcp} = -1$) and
    $CP$-even ($\xi_{\fcp} = +1$) samples are combined; $q = +1(-1)$ indicates
    events tagged with \Bz (\Bzbar).}
  \label{fig:btoccs_results}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\subsection{Getting from $\bm{\sphione}$ to $\bm{\phi_1}$}
The World Average value of \sphione\ leads to four solutions in
$\phi_1$: $21.7^\circ$, $68.3^\circ$, (21.7+180)$^\circ$ and
(68.3+180)$^\circ$. The ambiguity can be reduced by measuring $\cos
2\phi_1$ in the time-dependent angular analysis of \Bz$\to$$J/\psi
K^*$ decays: Belle (\babarsym) measures $\cos 2\phi_1$=$0.56\pm
0.79\pm 0.11$ ($\cos{2\beta}$=$2.72^{+0.50}_{-0.79}\pm 0.27$) using a
sample of about 275 (88) million \BB\ pairs~\cite{ref:jpsikstar}. The
angle ambiguity can be resolved also by the time-dependent Dalitz
analysis of neutral $D$$\to$$K_S^0 \pi^+ \pi^-$ decays, produced in decays
\Bzbar$\to$$D^{0(*)} h^0$ ($h^0$ is $\pi^0$, $\eta$ and
$\omega$)~\cite{ref:bondaretal}. The result from the Belle experiment
establishes the sign of $\cos 2 \phi_1$ to be positive at $98.3\%$
C.L.~\cite{ref:dh_dalitz} and strongly favours
$\phi_1$$(=\beta)$=$(21.7^{+1.3}_{-1.2})^\circ$ solution (see the UT
in Fig.~\ref{fig:btoccs_averages}).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[!tb]
  \centerline{%
    \begin{tabular}{c}
      \includegraphics[width=0.30\textwidth]{./plots/btoccs_BF_S_CP.eps} \\
      \includegraphics[width=0.40\textwidth]{./plots/rhoeta_wa_phi_small.eps}
    \end{tabular}
  }
  \caption{
    Upper plot: $CP$-violation parameter \sphione/\sbeta\ from the
    $b$$\to$\ccs\ decays, measured at B-factories and averaged by the
    HFAG. Lower plot: UT constraints from a global fit to the CKM
    matrix~\cite{ref:CKMfitter}. The 95\% C.L. area, bounded by red curve,
    is obtained when the angle measurements are excluded from the fit; the
    light blue contours show the direct constraints on the angles.}
  \label{fig:btoccs_averages}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\section{The angle $\bm{\phi_1/\beta}$ from $\bm{\btoccd}$ decays}
The decay modes governed by $b$$\to$\ccd\ processes are -- like
$b$$\to$\ccs\ decays -- dominated by a tree-level diagram and
sensitive to \sphione. However, due to non-negligible contribution of
gluonic penguins with a different weak phase, a few-percent direct
\CP\ violation and a deviation of mixing-induced \CP-violation
parameter $S_{\ccd}$ from \sphione\ is expected in the SM. Non-SM
processes could further enlarge the penguin contribution and lead to
\CP\ asymmetries, differing significantly from the ones measured in
$b$$\to$\ccs\ decays.

For \Bz\ decays into pure \CP\ eigenstates $D^+ D^-$ and $J/\psi
\pi^0$, extraction of \CP-violation coefficients is similar as for
$b$$\to$\ccs\ decays \cite{ref:dd_jpsipi0}. In case of \Bz\ decays
into $D^{*+}D^{*-}$ final state -- a mixture of \CP-odd and \CP-even
components -- the \CP-odd fractions have to be evaluated to extract
the \CP-violation coefficients.~Both experiments agree that
\Bz$\to$$D^{*+}D^{*-}$ decay is mostly \CP\
even~\cite{ref:dstardstar}. The measured values of \CP-violation
coefficients for $b$$\to$\ccd\ modes -- obtained by \babarsym\ (Belle)
using a sample of about 230 (152) million \BB\ pairs -- are summarised
in the table shown in Fig.~\ref{fig:ccbard_averages}. All results are
consistent with the tree-dominance SM scenario, but more data should
be analysed to observe also small deviations of $S_{\ccd}$=\sphioneeff\
and $A_{\ccd}$ from \sphione\ and 0, respectively.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[!t]
  \centerline{%
    \begin{tabular}{c c}
      \includegraphics[width=0.24\textwidth]{./plots/ccdS_CP.eps} &
      \includegraphics[width=0.24\textwidth]{./plots/ccdC_CP.eps} 
    \end{tabular}
  }
  \caption{
    Measured \CP-violation coefficients for \btoccd\ processes:
    Results for $S_{\ccd}$ are compatible with \sphione/\sbeta\ from
    \btoccs\ decays and no evidence for direct \CP\ violation is
    observed.}
  \label{fig:ccbard_averages}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\section{Penguin-dominated $\bm{\btosqq}$ decays}
In the SM, the flavour-changing $b$$\to$$s$ transitions can only
proceed through penguin loop diagrams. The dominant $b$$\to$\sqq\
penguin diagrams include the same weak phase as $b$$\to$\ccs\ decays,
so the $b$$\to$\sqq\ \CP-violation coefficients are predicted to
roughly follow the pattern: \Sfcp = $- \xi_{\fcp} \sphione$ and
\Afcp=0. However, differences from these values are expected in the
SM, since various processes with more than one weak phase contribute
significantly to $b$$\to$\sqq\ amplitudes. Furthermore, \CP\
asymmetries could also be modified due to non-SM loop contributions.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[!t]
  \centerline{%
    \begin{tabular}{l r}
      \includegraphics[width=0.24\textwidth]{./plots/sPengS_CP.eps} &
      \includegraphics[width=0.24\textwidth]{./plots/sPengC_CP.eps} \\
    \end{tabular}
  }%
  \caption{%
    Averages of measurements of the \CP-violation parameters in the
    \btosqq\ modes. No significant deviation from \btoccs\ values,
    $S=\sphione(\sbeta)$ and $A = -C = 0$, is observed.
  }
  \label{fig:sqqbar_results}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

The time-dependent \CP\ violation measurements of $b$$\to$\sqq\ decays
are performed for many different final states: $\phi K^0$,
$\eta^\prime K^0$, $f_0 K^0$, $\pi^0 K_S^0$, $\pi^0 \pi^0 K_S^0$,
$\omega K_S^0$, $\rho^0 K_S^0$, $K^+K^-K^0$ and $K_S^0K_S^0K_S^0$
\cite{ref:btoccs_belle,ref:btosqq_babar}.  The $B \to \phi K_S^0$
decay mode is the \btosqq\ analogue of the ``golden'' mode, since
these decays are in the SM described almost entirely by \btosss\
penguin diagram and their \CP\ asymmetries are expected to differ from
the ones measured in \btoccs\ by not more than a few percents. Like $B
\to J \psi K^0$, this decay mode is also experimentally favourable due
to the narrow $\phi$ resonance in the final state. The decay $B^0\to
\eta^\prime K^0$ is also interesting due to the largest branching
fraction among \btos\ modes ($\sim 6\times 10^{-5}$). Although not a
pure penguin mode, it is still \btos\ penguin-dominated and deviations
of \CP\ asymmetries from $b$$\to$\ccs\ case are in the SM expected to
be small. Experimentally challenging are the modes with no tracks
coming from the $B$-meson decay vertex, like \Bz$\to$$\pi^0 K_S^0$ or
pure $b$$\to$\sss\ penguin mode \Bz$\to$$K_S^0 K_S^0 K_S^0$. For these
modes the IP-constrained vertexing technique is used to determine the
\Bz\ decay-vertex position. The tables in
Fig.~\ref{fig:sqqbar_results} summarise results of measurements for
$b$$\to$\sqq\ penguin modes. No significant differences of \CP-violation
parameters with respect to the $S$=\sphione(\sbeta), $A$=$-C$=0
values are observed for any of the modes, but there is a 2.6~$\sigma$
difference for the na\"{i}ve average of \sphioneeff\ over all
$b$$\to$\sqq\ modes~\cite{ref:HFAG}.~However, such an average should
probably not be used, since each of the $b$$\to$\sqq\ decay modes is
sensitive to different SM contributions. Analyses of larger samples
are thus necessary before reaching any conclusions.

\section{Summary and conclusions}
The CP-violating parameter \sbeta/\sphione\ in charmonium decays is
now measured with an accuracy, better than $5\%$, owing to the
output of the B-factories. The measured value, consistent with the
SM expectations, is used as a reference point to confirm the
tree-dominance SM scenario in $b$$\to$\ccd\ decays and the absence of large
non-SM effects in penguin-dominated $b$$\to$\sqq\ decays. All measurements
are still statistically limited, thus analyses of larger samples are
eagerly awaited.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{thebibliography}{99}
% ==========
\bibitem{ref:CKM}
  N.\ Cabbibo, \prl{10}{1963}{531};
  M.\ Kobayashi and T.\ Maskawa, \pthp{49}{1973}{652}.
% ==========
\bibitem{ref:Belle}
  A.\ Abashian \textit{et al.} (Belle), \nima{479}{2002}{117}.
% ==========
\bibitem{ref:Babar}
  B.\ Aubert \textit{et al.} (\babarsym), \nima{479}{2002}{1}.
% ==========
\bibitem{ref:btoccs_belle}
  K.\ Abe \textit{et al.} (Belle), \hepex{0507037}.
% ==========
\bibitem{ref:btoccs_babar}
  B.\ Aubert \textit{et al.} (\babarsym), \prl{94}{2005}{161803}.
% ==========
\bibitem{ref:HFAG}
  Heavy Flavour Averaging Group (HFAG), 
  \textsf{http://www.slac.stanford.edu/xorg/hfag} .
% ==========
\bibitem{ref:CKMfitter}
  J.\ Charles \textit{et al.} (CKMfitter), \epjc{41}{2005}{1}; 
  updates available at: \textsf{http://ckmfitter.in2p3.fr} .
% ==========
\bibitem{ref:jpsikstar}
  R.\ Itoh, Y.\ Onuki \textit{et al.} (Belle), \prl{95}{2005}{091601};
  B.\ Aubert \textit{et al.} (\babarsym), \prd{71}{2005}{032005}.
% ==========
\bibitem{ref:bondaretal}
  A.\ Bondar, T.\ Gershon and P.\ Krokovny, \plb{624}{2005}{1}.
% ==========
\bibitem{ref:dh_dalitz}
  P.\ Krokovny \textit{et al.} (Belle), \hepex{0605023}.
% ==========
\bibitem{ref:dd_jpsipi0}
  B.\ Aubert \textit{et al.} (\babarsym), \prl{95}{2005}{131802} 
  and \prd{74}{2006}{011101};   
  S.\ U.\ Kataoka \textit{et al.} (Belle), \prl{93}{2005}{261801}.  
% ==========
\bibitem{ref:dstardstar}
  H.\ Miyake \textit{et al.} (Belle), \plb{618}{2005}{34};
  B.\ Aubert \textit{et al.} (\babarsym), \prl{95}{2005}{151804}.  
% ==========
\bibitem{ref:btosqq_babar}
  B.\ Aubert \textit{et al.}(\babarsym),\prd{71}{2005}{091102};
  \hepex{0507087}; \hepex{0408095}; \prd{71}{2005}{111102};
  \hepex{0508017}; \hepex{0603040}; \hepex{0507016}; \hepex{0507052}.
 
\end{thebibliography}
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\end{document}
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