\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{feynmp} \usepackage{pst-pdf} \usepackage{hyperref} \usepackage{xcolor} \setbeamertemplate{footline}{\insertframenumber/\inserttotalframenumber} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \definecolor{mygreen}{cmyk}{0.82,0.11,1,0.25} %\DeclareCaptionFont{uiblack}{\color{uiblack}} %\DeclareCaptionFont{uipoppy}{\color{uipoppy}} %\captionsetup{labelfont={uipoppy},textfont=uiblack} % see the macros.tex file for definitions \renewcommand{\PKs}{{\HepParticle{K}{S}{}\xspace}} \newcommand{\at}{\makeatletter @\makeatother} %-------------------------------------------------------------------- % Introduction %-------------------------------------------------------------------- \usetheme{Sybila} \title[ Rare beauty and charm decays at LHCb]{ Rare beauty and charm decays at LHCb} \author{Marcin Chrz\k{a}szcz$^{1}$ \\ \footnotesize{on behalf of the LHCb collaboration}} \institute{$^1$~University of Zurich \\{~}\\ Heavy Quarks and Leptons 2014 } \date{\today} \begin{document} % --------------------------- SLIDE -------------------------------------------- \frame[plain]{\titlepage} \author{Marcin Chrz\k{a}szcz} % ------------------------------------------------------------------------------ % --------------------------- SLIDE -------------------------------------------- \institute{~(UZH)} %-------------------------------------------------------------------- % OUTLINE %-------------------------------------------------------------------- \section[Outline]{} \begin{frame} %\tableofcontents %FIXME! \begin{enumerate} \item Rare $\PB$ decays: \begin{itemize} \item $\PB \to \PK \Ppi \Ppi \Pphoton$ \item $\PB \to \mu \mu$. \item $\Pbeauty \to \Pstrange \Plepton \Plepton$. \end{itemize} \item Charm decays: \begin{itemize} \item $\PD \to \mu \mu$. \end{itemize} \end{enumerate} \end{frame} %------------------------------------------------------------------- % Introduction %------------------------------------------------------------------- % % Set the background for the rest of the slides. % Insert infoline %\setbeamertemplate{background} % {\includegraphics[width=\paperwidth,height=\paperheight]{slide_bg}} %\setbeamertemplate{footline}[bunsentheme] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\setbeamertemplate{background} % {\includegraphics[width=\paperwidth,height=\paperheight]{slide_bg}} %\setbeamertemplate{footline}[bunsentheme] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\section{LHCb detector} %\begin{frame}\frametitle{LHCb detector} %\begin{columns} %\column{3.in} %\begin{center} %\includegraphics[width=0.98\textwidth]{det.jpg} %\end{center} %\column{2.0in} %\begin{footnotesize} % LHCb is a forward spectrometer: % \begin{itemize} % \item Excellent vertex resolution. % \item Efficient trigger. % \item High acceptance for $\Ptau$ and $\PB$. % \item Great Particle ID % \end{itemize} %\end{footnotesize} %\end{columns} %\end{frame} \section{Introduction} \begin{frame}\frametitle{Why rare decays?} \begin{columns} \column{4in} \begin{itemize} \item CKM structure in SM allows only the charged interactions to change flavour. \begin{itemize} \item Other interactions are flavour conserving. \end{itemize} \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 in SM $\to$~Rare decays. \end{itemize} \end{itemize} \begin{center} \includegraphics[scale=0.3]{hql/lupa.png} \includegraphics[scale=0.3]{hql/example.png} \end{center} \column{1.5in} \includegraphics[width=0.62\textwidth]{hql/couplings.png} \end{columns} \end{frame} \begin{frame}\frametitle{Tools} \begin{itemize} \item \textbf{Operator Product Expansion and Effective Field Theory} \end{itemize} \begin{columns} \column{0.1in}{~} \column{3.2in} \begin{align*} H_{eff} = - \dfrac{4G_f}{\sqrt{2}} V V^{\ast} \sum_i \left[\underbrace{C_i(\mu)O_i(\mu)}_\text{left-handed} +\underbrace{C'_i(\mu)O'_i(\mu)}_\text{right-handed}\right] \end{align*} \column{2in} \begin{tiny} \begin{description} \item[i=1,2] Tree \item[i=3-6,8] Gluon penguin \item[i=7] Photon penguin \item[i=9.10] EW penguin \item[i=S] Scalar penguin \item[i=P] Pseudoscalar penguin \end{description} \end{tiny} \end{columns} \begin{center} \includegraphics[width=0.85\textwidth,height=3cm]{hql/all.png} \end{center} \end{frame} \begin{frame}\frametitle{Radiative decays} \begin{columns} \column{5in} \begin{itemize} \item $\PBzero \to \PKstar \Pphoton$ - first observed penguin! \begin{itemize} \item CLEO, [\href{http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.71.674}{\color{blue}PRL, 71 (1993) 674}] \end{itemize} \item B-factories probed NP measuring, inclusively/ semi-inclusively $\mathcal{B}(\Pbeauty \to \Pstrange \Pphoton)$ \end{itemize} \column{0.1in}{~} \end{columns} \begin{columns} \column{3in} \begin{itemize} \item Is there anyway LHCb can contribute? \begin{itemize} \item Measurements of $\mathcal{B}(\Pbeauty \to \Pstrange \Pphoton)$ very difficult. \item Can probe probe polarization! \end{itemize} \end{itemize} \column{2in} \includegraphics[width=0.85\textwidth]{hql/btosgamma.png} \end{columns} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{columns} \column{5in} \begin{itemize} \item In SM, photons form $\Pbeauty \to \Pstrange \Pphoton$ decays are left handed. \begin{itemize} \item Charged current interactions: $C_7/C'_7\sim m_{\Pbeauty}/m_{\Pstrange}$ \end{itemize} \item Can test $C_7/C'_7$ using: \begin{itemize} \item Mixing induced CP violation: \href{http://arxiv.org/abs/hep-ph/9704272}{\color{blue}Atwood et. al. PRL 79 (1997) 185-188} \item $\PLambdab$ baryons: \href{http://arxiv.org/abs/hep-ph/0108074}{\color{blue}Hiller \& kagan PRD 65 (2002) 074038} \end{itemize} \end{itemize} \column{0.1in}{~} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \begin{frame}\frametitle{Photon polarization from $\PB^+ \to \PK^{+} \Ppi^- \Ppi^+ \Pphoton$} \begin{columns} \column{3.5in} \begin{itemize} \item OR: Study $\PB \to \PK^{\ast \ast} \Pphoton$ decays like $\PBplus \to \PK_1(1270) \Pphoton$ \begin{itemize} \item \href{http://arxiv.org/abs/hep-ph/0205065}{\color{blue}Gronau \& Pirjol PRD 66 (2002) 054008} \end{itemize} \item The trick is to get the photon polarization from the up-down asymmetry of photon direction in the $\PK \Ppi \Ppi$ rest frame. \begin{itemize} \item No asymmetry $\rightarrow$ Unpolarised photons. \end{itemize} \item Conceptionally this measurement is similar to the Wu experiment, which first observed parity violation. \end{itemize} \column{1.5in} \includegraphics[width=0.95\textwidth]{hql/polarization.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PB^+ \to \PK^{+} \Ppi^- \Ppi^+ \Pphoton$ at LHCb} \begin{columns} \column{3.in} \begin{itemize} \item LHCb looked at $\PBplus \to \PKplus \Ppiminus \Ppiplus \Pphoton$, using un-converted photons. \item Got over 13.000 candidates in $3~fb^{-1}$! \item \href{http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.161801}{\color{blue} Phys. Rev. Lett. 112, 161801 } \item $\PKplus \Ppiminus \Ppiplus$ system has variety of resonances. \begin{itemize} \item $\PK \Ppi \Ppi \Ppi$system studied inclusively. \item Bin the mass and look for polarization there. \end{itemize} \end{itemize} \column{2in} {~} \includegraphics[width=0.95\textwidth]{hql/plotspolarization.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}%\frametitle{$\color{white} B^+ \to K^{+} \pi^- \pi^+ \gamma$ at LHCb} \begin{center} {\color{red} Fit with $\color{red}(C_7'-C_7)/(C_7'+C_7)=0$}, {\color{blue} Best fit} \includegraphics[width=0.93\textwidth]{hql/photonfit.png} \end{center} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Up-down asymmetry} \begin{columns} \column{3.in} \begin{itemize} \item Combining the 4 bins, gives $5.2\sigma$ significance from no photon polarization hypothesis. \item Unfortunately without understanding the hadron system it is impossible to tell if the photon is left or right -handed. \end{itemize} \column{2in} {~} \includegraphics[width=0.95\textwidth]{hql/aud.png} \end{columns} \begin{center} $\rightarrow$~ First observation of photon polarization in $\Pbeauty \to \Pstrange \Pphoton$! \end{center} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \Pmu^+ \Pmu^-$} \begin{columns} \column{3.2in} \begin{itemize} \item Clean theoretical prediction, GIM and helicity suppressed in the SM: \begin{itemize} \item $\mathcal{B}(\PBs \to \Pmuon \APmuon) = (3.65 \pm 0.23)\times 10^{-9}$ \item $\mathcal{B}(\PBzero \to \Pmuon \APmuon) = (1.06 \pm 0.09)\times 10^{-10}$ \end{itemize} \item Sensitive to contributions from scalar and pesudoscalar couplings. \item Probing: MSSM, higgs sector, etc. \item In MSSM: $\mathcal{B}(\PBs \to \Pmuon \APmuon) \sim \tan^6 \beta /m_A^4$ \end{itemize} \column{1.5in} {~} \includegraphics[width=0.95\textwidth]{hql/bs2mumu1.png}\\ \includegraphics[width=0.95\textwidth]{hql/bs2mumu2.png}\\ \includegraphics[width=0.6\textwidth]{hql/higgspen.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \Pmu^+ \Pmu^-$ searches} \begin{columns} \column{5in} \begin{itemize} \item Background rejection power is a key feature of rare decays $\rightarrow$ use multivariate classifiers (BDT) and strong PID. \end{itemize} \column{0.1in}{~} \end{columns} \begin{columns} \column{2.5in} \includegraphics[width=0.95\textwidth]{hql/BDT.png} \column{2.5in} \includegraphics[width=0.95\textwidth]{hql/mass.png} \end{columns} \begin{itemize} \item Normalize the BF to $\PBplus \to \PJpsi(\mu\mu) \PKplus$ and $\PBzero \to \PK \Ppi$. \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \Pmu^+ \Pmu^-$ Results} \begin{columns} \column{2.in} \begin{itemize} \item Nov. 2012: \begin{itemize} \item First evidence $3.5\sigma$ for $B^0 \rightarrow \mu^+ \mu^-$. with $2.1~fb^{-1}$. \end{itemize} \item Summer 2013: \begin{itemize} \item Full data sample: $3~fb^{-1}$. \end{itemize} \end{itemize} \column{3.0in} \includegraphics[width=0.95\textwidth]{hql/mass2.png} \end{columns} \begin{itemize} \item Measured BF:\\ $\mathcal{B}(\PBs \to \Pmuon \APmuon) =(2.9^{+1.1}_{-1.0}(stat.)^{+0.3}_{-0.1}(syst.))\times 10^{-9}$ \item $4.0 \sigma$ significance! \item $\mathcal{B}(\PBzero \to \Pmuon \APmuon) < 7 \times 10^{-10}$ at $95\%$ CL \item \href{http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.110.021801}{\color{blue} PRL 110 (2013) 021801 } \item \href{http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.101805}{\color{blue} CMS result: PRL 111 (2013) 101805} \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{LHCb+CMS Combination} \begin{Large} \begin{center} $\mathcal{B}(\PBs \to \Pmuon \APmuon) =(2.9 \pm 0.7 )\times 10^{-9}$\\ $\mathcal{B}(\PBzero \to \Pmuon \APmuon) =(3.6^{+1.6}_{-1.4} )\times 10^{-10}$ \end{center} \end{Large} \includegraphics[width=0.95\textwidth]{hql/limits.png} Full combination CMS+LHCb with simultaneous fit close to completion! \begin{itemize} \item \href{https://cds.cern.ch/record/1564324/files/LHCb-CONF-2013-012.pdf}{\color{blue}LHCb-CONF-2013-012} \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \PK^{\ast} \Pmu \Pmu$ angular distributions} \begin{columns} \column{2.5in}{~} \begin{itemize} \item Can probe photon polarization using virtual photons in $\Pbeauty \to \Pstrange \Plepton \Plepton$. \item LHCb favourite: $\PBzero \to \PKstar \mu \mu$. \item Sensitive to lot of new physics models. \item Decay described by three angles $\theta_l, \theta_K, \phi$ and dimuon invariant mass $q^2$. \item Analysis is performed in bins of $q^2$. \end{itemize} \column{2.5in} \includegraphics[width=0.95\textwidth]{hql/angles.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \PK^{\ast} \Pmu \Pmu$ angular distributions} \begin{itemize} \item Angular distributions depends on 11 angular terms: \includegraphics[width=0.95\textwidth]{hql/eq.png} \end{itemize} where the $J_i$ are bilinear combinations of helicity amplitudes. \begin{itemize} \item Not enough events in our data sample to fit for 11 parameters $\rightarrow$ need to simplify! \item Can use symmetries, to reduced the the parameters \\ to 9 $\rightarrow$ still a bit large! \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \PK^{\ast} \Pmu \Pmu$ Folding} \begin{itemize} \item One can simplify the angular distribution by folding: eg. $\phi \to \phi +\pi$ for ($\phi<0$). \item Cancels terms with $\cos \phi$ and $\sin \phi$. \end{itemize} \includegraphics[width=0.95\textwidth]{hql/eq2.png} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{$\PBzero \rightarrow \PK^{\ast} \Pmu \Pmu$ angular distributions } \begin{itemize} \item Different foldings cancel different angular observables. \href{http://arxiv.org/abs/1308.1707}{\color{blue}[PRL 111 191801 (2013)]} \includegraphics[width=0.95\textwidth]{hql/ps.png} \item Observables $P'_{4,5} = S_{4,5}/\sqrt{F_L(1-F_L)}$ \item Leading form-factor uncertainties cancel. \item In $1~fb^{-1}$, LHCb observes a local discreapncy of $3.7\sigma$ in $P'_5$. \item Probability that at least one bin varies by this much is $0.5\%$. \item SM prediction form: \href{http://arxiv.org/abs/1303.5794}{\color{blue} JHEP 05 (2013) 137} \end{itemize} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Understanding the $\PBzero \rightarrow \PK^{\ast} \Pmu \Pmu$ anomaly 1/2} \begin{columns} \column{3.5in} \begin{itemize} \item Matias, Decotes-Genon \& Virto performed a global fit to the avaible $\Pbeauty \to \Pstrange \Pphoton$ abd $\Pbeauty \to \Pstrange \Plepton \Plepton$. \item Found $4.5 \sigma$ discrepancy from SM. \item Fit favours $C_9^{NP}=1.5$ \item \href{http://arxiv.org/abs/1307.5683}{\color{blue} PRD 88 074002 (2013)} \end{itemize} \begin{itemize} \item Straub \& Altmannshofer performed a global analysis and found discrepancies at the level of $3\sigma$. Data again best describes a modified $C_9$. \item Data can be explained by introducing a flavour changing $\PZprime$ boson, with mass $\mathcal{O}(10~TeV)$ \item \href{http://arxiv.org/abs/1212.2263}{\blue{EPJC 73 2646 (2013)}} \end{itemize} \column{1.5in} \includegraphics[width=0.9\textwidth]{hql/np.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\begin{frame}\frametitle{Understanding the $\color{white}B^{0} \rightarrow K^{\ast} \mu \mu$ anomaly 2/2} %\begin{columns} %\column{3in} %\includegraphics[width=0.99\textwidth]{hql/c9.png} %\column{2in} %\begin{itemize} %\item High $q^2$ differential BF suggests are all below SM. %\item Better consistency with $C_9^{NP}=-1.5$ %\end{itemize} %\end{columns} %\end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Lepton universality} \begin{columns} \column{3.0in} \begin{itemize} \item If $\PZprime$ is responsible for the $P'_5$ anomaly, does it couple equally to all flavours? \includegraphics[width=0.9\textwidth]{hql/uni2.png} \item Challenging analysis. \item Migration of events modeled by MC. \item Correct bremsstrahlung. \item Take double ratio with $\PBplus \to \PJpsi \PKplus$ to cancel systematics. \item In $3fb^{-1}$, LHCb measures $R_K=0.745^{+0.090}_{-0.074}(stat.)^{+0.036}_{-0.036}(syst.)$ \item Consistent with SM at $2.6\sigma$. \end{itemize} \column{2.0in} \includegraphics[width=0.99\textwidth]{hql/universality.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{FCNC in charm decays} \begin{columns} \column{3.0in} \begin{itemize} \item GIM cancelation effective in $\Pcharm \to \Pup$ transitions due to small size of $m_b$. \item SM prediction:~$\mathcal{B}(\PDzero \to \mu \mu) \sim 6 \times 10^{-11}$ \end{itemize} \column{1.5in} \includegraphics[width=0.9\textwidth]{hql/ds2mumu.png} \end{columns} \includegraphics[width=0.9\textwidth]{hql/ds2mumu2.png} \begin{small} \begin{itemize} \item Use $\PDstar^{\pm}$ and exploit small $\Delta m$ for background suppression. \item Limitation is $\pi \to \mu$ mis-id. \item Limit: $\mathcal{B}(\PDzero \to \mu \mu)<6.2\times 10^{-9}$ at $90\%$ CL \item \href{http://arxiv.org/abs/1305.5059}{\color{blue} PLB 725 (2013) 15-24} \end{itemize} \end{small} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Conclusions} \begin{columns} \column{3.2in} \begin{itemize} \item Rare decays play important role in hutting NP. \item Can access NP scales beyond reach of GPD. \item Tension in $\Pbeauty \to \Pstrange \Plepton \Plepton$, theory correct? \item List of decays presented in this talk is just a tip of iceberg: \begin{itemize} \item Please look at ours: isospin, $A_{CP}$. \item More are on their way. \end{itemize} \end{itemize} \column{2in} \includegraphics[width=0.9\textwidth]{hql/higgs_boring.png} \end{columns} \end{frame} \end{document}