\documentclass[xcolor=svgnames]{beamer} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage{polski} %\usepackage{amssymb,amsmath} %\usepackage[latin1]{inputenc} %\usepackage{amsmath} %\newcommand\abs[1]{\left|#1\right|} \usepackage{amsmath} \newcommand\abs[1]{\left|#1\right|} \usepackage{hepnicenames} \usepackage{hepunits} \usepackage{color} \usepackage{braket} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \definecolor{mygreen}{cmyk}{0.82,0.11,1,0.25} %-------------------------------------------------------------------- % Introduction %-------------------------------------------------------------------- \usetheme{Sybila} \title[Recent BaBar results on CP violation in B-meson decays]{ Recent BaBar results on CP violation in B-meson decays} \author{Marcin Chrz\k{a}szcz$^{1}$ \\ \footnotesize{on behalf of the BaBar collaboration}} \institute{$^1$~University of Zurich \\{~}\\ Deep-Inelastic Scattering 2015 } \date{\today} \begin{document} % --------------------------- SLIDE -------------------------------------------- \frame[plain]{\titlepage} \author{Marcin Chrz\k{a}szcz} % ------------------------------------------------------------------------------ % --------------------------- SLIDE -------------------------------------------- \institute{~(UZH)} % --------------------------- SLIDE -------------------------------------------- \section{BaBar Detector} \begin{frame}\frametitle{BaBar Detector} \begin{columns} \column{2.5in} \begin{itemize} \item PEP-II, an asymmetric $\Pelectron \APelectron$ collider. \item Operating mostly at $\PUpsilon(4S)$ threshold. \end{itemize} \includegraphics[width=0.95\textwidth]{images/bbr_det.png} \column{2.5in} \includegraphics[width=0.95\textwidth]{images/bbr_lumi.png} \end{columns} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \end{frame} \begin{frame}\frametitle{B factories} \begin{columns} \column{2.5in} \includegraphics[width=0.95\textwidth]{images/upsilon1.png}\\ \includegraphics[width=0.95\textwidth]{images/topo.png} \column{2.5in} \begin{itemize} \item $\PB$ mesons produced in a clean environment. \item Just above the $m(\PB \PB)$ threshold. \end{itemize} \includegraphics[width=0.95\textwidth]{images/ee_col.png} \end{columns} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \end{frame} \section{CP violation in $\PB \APB$ mixing} \begin{frame}\frametitle{$\PBzero \APBzero$ mixing} \begin{itemize} \item Neutral mesons couple to their anti particles via weak interactions. \end{itemize} \begin{columns} \column{3.4in} \begin{itemize} \item $\PBzero \Leftrightarrow \APBzero$, $\PB s\Leftrightarrow \APBs$, $\PK \Leftrightarrow \APK$. \item We can writhe the weak eigenstates as: \end{itemize} \begin{equation*} \ket{B_{L/H}} = \dfrac{1}{\sqrt{p^2+q^2}} (p \ket{\PBzero} \pm q \ket{\APBzero}) \end{equation*} \begin{itemize} \item Then the CP asymmetry can can be written as: \end{itemize} \begin{equation*} A_{CP} = \dfrac{\mathcal{P}(\APBzero \to \PBzero) - \mathcal{P}(\PBzero \to \APBzero) }{\mathcal{P}(\APBzero \to \PBzero) + \mathcal{P}(\PBzero \to \APBzero)}\approx 2(1-|\frac{q}{p}|) \end{equation*} \column{1.5in} \begin{center} \includegraphics[width=0.99\textwidth]{images/Bmixing_dia.png} \end{center} \end{columns} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{itemize} \item $\PUpsilon(4S)$ has an anti-symmetric state: $\dfrac{1}{\sqrt{2}} (\PBzero(t_1) \APBzero(t_2) - \APBzero(t_1) \PBzero(t_2)$ \item One $\PB$ is a specific flavour state tags the other one. \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Inclusive dilepton measurement} \begin{itemize} \item $\PB$ mesons decay in $\sim 10\%$ semileptonicaly. \item Charge of lepton determines the $\PB$ meson flavour. \item If one observes same sign leptons $\to$ mixing occurred: \end{itemize} \begin{columns} \column{0.5in} {~} \column{2.5in} \begin{itemize} \item $\Plepton^- \Plepton^{+}$: no mixing \item $\Plepton^- \Plepton^{-}$: $\PBzero \to \APBzero$. \item $\Plepton^+ \Plepton^{+}$: $\APBzero \to \PBzero$. \end{itemize} \column{2in} \includegraphics[width=0.65\textwidth]{images/semillep.png} \end{columns} \begin{itemize} \item Writing down the mixing provabilities~(time integrated): \end{itemize} \begin{equation*} \mathcal{P}^{\pm \pm} \propto (1 \pm A_{CP}) \chi_d \end{equation*} \begin{equation*} \mathcal{P}^{\pm \mp} \propto (1 -\chi_d) \end{equation*} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Detector effects} \begin{footnotesize} \begin{itemize} \item Detector is not a perfect device $\to$ Introduced charge asymmetries $a_{\Plepton_j}$ for each $\Plepton_j$. \item $\PUpsilon(4S)$ also goes to $\PBplus \PBminus$. Contribution: $r_B = N_{\PB^+ \PB^-}/N_{\PBzero \APBzero}$. \item Time integrated probability gets modified: \begin{align*} \mathcal{P}^{\pm \pm} \propto (1 \pm a_{\Plepton_1} \pm a_{\Plepton_2} \pm A_{CP}) \chi_d \\ \mathcal{P}^{\pm \mp} \propto (1 -\chi_d + r_B)(1 \pm a_{\Plepton_1} \mp a_{\Plepton_2} ) \end{align*} \item Summing over all events in $\Plepton_1 \Plepton_2 \in \lbrace \Pe \Pe, \Pe \Pmu, \Pmu \Pe, \Pmu \Pmu \rbrace$ categories: \begin{align*} N^{\pm \pm}_{\Plepton_1 \Plepton_2} = 1/2 N^0_{\Plepton_1 \Plepton_2} (1 \pm a_{\Plepton_1} \pm a_{\Plepton_2} \pm A_{CP}) \chi_d^{\Plepton_1 \Plepton_2}\\ N^{\pm \mp}_{\Plepton_1 \Plepton_2}= 1/2 N^0_{\Plepton_1 \Plepton_2} (1 -\chi_d^{\Plepton_1 \Plepton_2} + r_B)(1 \pm a_{\Plepton_1} \mp a_{\Plepton_2} ) \end{align*} \item We got 16 observables, and 13 unknowns. $a_{\Plepton_j}$ highly correlated. \item Adding events containing only single electron for $a_{\Pe}$ constrain. \item 17 observables as input to $\chi^2$ fit, extracting: $A_{CP}$, 4 signal yields,\\ 4 efficiency asymmetries, 4 mixing probabilities. \end{itemize} \end{footnotesize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Fit results} \begin{center} \begin{footnotesize} \begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{$A_{CP} = (-3.9 \pm 3.5)\times 10^{-3}$} & \multicolumn{2}{c}{ \includegraphics[height=0.5cm]{images/Babar_with_banner.jpg}~\href{http://arxiv.org/abs/1411.1842}{PRL 114, 081801 (2015)} }\\ \hline %\hline $N^0_{\Pe\Pe}$ & $N^0_{\Pe\Pmu}$ & $N^0_{\Pmu\Pe}$ & $N^0_{\Pmu\Pmu}$ \\ $430875 \pm 515$ & $365343 \pm 429$ & $458200 \pm 480$ & $268077 \pm 381$ \\ $\chi_d^{\Pe\Pe}$ & $\chi_d^{\Pe\Pmu}$ & $\chi_d^{\Pmu\Pe}$ & $\chi_d^{\Pmu\Pmu}$ \\ $0.2248 \pm 0.0006$ & $0.1769 \pm 0.0006$ & $0.1754 \pm 0.0005$ & $0.2032 \pm 0.0007$ \\ $a^{\Pe 1}$ & $a^{\Pe 2}$ & $a^{\Pmu 1}$ & $a^{\Pmu 2}$ \\ $0.0034 \pm 0.0006$ & $0.0030 \pm 0.006$ & $-0.0056 \pm 0.0011$ & $-0.0065 \pm 0.0011$ \\ \hline \end{tabular} {~}\\ \begin{columns} \column{0.5in}{~} \column{2.5in} \includegraphics[width=0.75\textwidth]{images/pull.png} \begin{itemize} \item Result $A_{CP} = (-3.9 \pm 3.5 \pm 1.9 )\times 10^{-3}$ in agreement with SM. \end{itemize} \column{2.5in} \includegraphics[width=0.76\textwidth]{images/hfag.png} \end{columns} \end{footnotesize} \end{center} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Flavour-changing neutral current} \begin{itemize} \item CKM structure in SM allows only the charged interactions to change flavour. \item One can escape the CKM structure and produce $\Pbottom \to \Pstrange$ and $\Pbottom \to \Pdown$ only at loop level. \begin{itemize} \item This kind of processes are suppressed by the GIM in SM $\to$~Rare decays. \end{itemize} \item LHCb already sees a $3.7~\sigma$ deviation in the angular observables in $\PBzero \to \PKstar \Pmuon \APmuon$. See my talk LINK. \item Here we present CP observables in $b \to s \Pphoton$ and $b \to s \Plepton \Plepton$ decays. \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Flavour-changing neutral current} \begin{itemize} \item CKM structure in SM allows only the charged interactions to change flavour. \item One can escape the CKM structure and produce $\Pbottom \to \Pstrange$ and $\Pbottom \to \Pdown$ only at loop level. \begin{itemize} \item This kind of processes are suppressed by the GIM in SM $\to$~Rare decays. \end{itemize} \item LHCb already sees a $3.7~\sigma$ deviation in the angular observables in $\PBzero \to \PKstar \Pmuon \APmuon$. See my talk LINK. \item Here we present CP observables in $b \to s \Pphoton$ and $b \to s \Plepton \Plepton$ decays. \end{itemize} \end{frame} \end{document}