\documentclass[]{beamer} \setbeamertemplate{navigation symbols}{} \usepackage{beamerthemesplit} \useoutertheme{infolines} \usecolortheme{dolphin} %\usetheme{Warsaw} \usetheme{progressbar} \usecolortheme{progressbar} \usefonttheme{progressbar} \useoutertheme{progressbar} \useinnertheme{progressbar} \usepackage{graphicx} %\usepackage{amssymb,amsmath} \usepackage[latin1]{inputenc} \usepackage{amsmath} \usepackage{iwona} \progressbaroptions{imagename=images/lhcb} %\usetheme{Boadilla} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \definecolor{mygreen}{cmyk}{0.82,0.11,1,0.25} \setbeamertemplate{blocks}[rounded][shadow=false] \addtobeamertemplate{block begin}{\pgfsetfillopacity{0.8}}{\pgfsetfillopacity{1}} \setbeamercolor{structure}{fg=mygreen} \setbeamercolor*{block title example}{fg=mygreen!50, bg= blue!10} \setbeamercolor*{block body example}{fg= blue, bg= blue!5} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\beamersetuncovermixins{\opaqueness<1>{25}}{\opaqueness<2->{15}} \title{Update on measurement of Bose-Einstein Correlations} \author{\underline{Marcin Chrzaszcz}$^{1,2}$, Marcin Kucharczyk$^{1,3}$,\\Tadeusz Lesiak$^1$} \date{\today} \begin{document} { \institute{$^1$ Krakow, $^2$ Zurich, $^3$ Milano} \setbeamertemplate{footline}{} \begin{frame} \logo{ \vspace{2 mm} \includegraphics[height=1cm,keepaspectratio]{images/ifj.png}~ \includegraphics[height=1cm,keepaspectratio]{images/uzh.jpg}} \titlepage \end{frame} } \institute{UZH,IFJ} \section[Outline]{} \begin{frame} \tableofcontents \end{frame} %normal slides \section{Theory introduction} %\begin{bibunit}[apalike] \subsection{Two particle Correlations} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%55 \begin{frame}\frametitle{Two particle Correlations} \begin{itemize} \item Let $W(p_1,p_2,x_1,x_2)$ be a Wigner function. \item For identical particles observed distributions of momentum takes the form: \end{itemize} \begin{small} \begin{align}\label{eq:one} %\begin{equation} \Omega(p_1,p_2)= \int dx_1 dx_2 (W(p_1,p_2,x_1,x_2)+ e^{(x_1-x_2) (p_1-p_2)} W(P_{12},P_{12},x_1,x_2)) \nonumber \\ \equiv \Omega_0(p_1,p_2)[1+C(p_1,p_2)] \end{align}\end{small} \begin{itemize} \item Space distribution $x_1-x_2$ can be access via $C(p_1,p_2)$. \end{itemize} \end{frame} %\end{bibunit}[apalike] \begin{frame}\frametitle{Two particle Correlations} \begin{itemize} \item Assuming no correlation in space Wiger function can be factorised: \end{itemize} \begin{small} \begin{equation} %\begin{equation} W(p_1,p_2,x_1,x_2)= \Omega_0(p_1,p_2)w(p_1,x_1)w(p_2,x_2) \end{equation}\end{small} \begin{itemize} \item This simplifies eq.(\ref{eq:one}): $\Omega(p_1,p_2)=\Omega_0(p_1,p_2)[1+\int dx W(P_12,x)e^{ix(p1-p2)}]$ \item The 2 body correlation can be written as: \begin{equation} C_2(p_1,p_2)=\vert \int dx W(P_{12},x)e^{ix(p1-p2)} \vert^2 \end{equation} \item All LEP experiments measured BEC. \end{itemize} \end{frame} %\end{bibunit}[apalike] \subsection{Goldhaber parametrisation} \begin{frame}\frametitle{Goldhaber parametrisation} Following Goldhaber\footnote{Goldhaber et. al. Phys. Rev. Lett 3 (1959)} we can parametrize the correlation function: \begin{equation} C_2(q_1,q_2) = N(1 \pm \lambda e^{-Q^2 R^2}) \end{equation} ,where $Q=q_1-q_2$, $R$ radius of the source, $\lambda$ chaotic parameter, $N$ normalization. Second order correlation function is defined: \begin{equation} C_2(q_1,q_2) = \dfrac{\mathcal{P}(q_1,q_2)}{\mathcal{P}(q_1)\mathcal{P}(q_2)} \equiv \dfrac{\mathcal{P}(q_1,q_2)}{\mathcal{P}(q_1,q_2)^{ref}} \end{equation} \end{frame} %\end{bibunit}[apalike] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Reference samples} $\mathcal{P}(q_1,q_2)^{ref}$ can be estimated from reference samples: \begin{enumerate} \item MC without BEC. \begin{itemize} \item Absence of Coulomb effects in generator. \item Data-MC agreement. \end{itemize} \item Unlike-sign charge particles \begin{itemize} \item Resonances contribution \item Derived from data \end{itemize} \item Event-mixing \begin{itemize} \item Mixing event by events. \item PV mixing. \end{itemize} \end{enumerate} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%55555 \begin{frame}\frametitle{LCMS} \begin{columns} \column{2.8in} \begin{itemize} \item Longitudinal Centre-of-Mass System(LCMS) is defined as a system where sum of 3-momenta $\overrightarrow{q_1} + \overrightarrow{q_2}$ is perpendicular to a reference axis(jet, thrust, z). \begin{scriptsize} \item $Q^2$ can be written:\\ $Q^2=1+\lambda e^{-Q_{t,out}^2R_{t,out}^2-Q_{t,side}^2R_{t,side}^2-Q_{t,long}^2R_{t,long}^2} = 1+\lambda e^{-Q_{t,\bot}^2R_{t,bot}^2-Q_{t,\|}^2R_{t,\|}^2}$ \end{scriptsize} \item One can perform 1,2 or 3 dim analysis. \end{itemize} \column{3in} \includegraphics[scale=.14]{images/lcms.png} \end{columns} \end{frame} \begin{frame}\frametitle{LEP and CMS results} \only<1> { \includegraphics[scale=.215]{images/table.png} } \only<2> { \includegraphics[scale=.195]{images/table2.png} } \end{frame} \section{Selection} \begin{frame}\frametitle{Preselection} \begin{columns} \column{3.5in} \begin{enumerate} \item MiniBias Stripping lines. \item 2011 data. \item Select all particles that come from PV with cuts: \begin{itemize} \item $TRKChi2<2.6$ \item $IP<0.2mm$ \item $IPCHI2 <2.6$ \item $PIDNN(\pi, K)>0.25$ \item $ghostNN<0.3$ \item $P>0.2GeV$ \item $Pt>0.1GeV$ \end{itemize} \end{enumerate} \column{2.2in} \includegraphics[scale=.115]{images/ip.png}\\ \includegraphics[scale=.115]{images/ipChi2.png}\\ \includegraphics[scale=.115]{images/ghostNN.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Selection} \begin{columns} \column{3.5in} \begin{enumerate} \item MiniBias Stripping lines. \item 2011 data. \item Select all particles that come from PV with cuts: \begin{itemize} \item $TRKChi2<2.6$ \item $IP<0.2mm$ \item $IPCHI2 <2.6$ \item $PIDNN(\pi, K)>0.25$ \item $ghostNN<0.3$ \item $P>0.2GeV$ \item $Pt>0.1GeV$ \end{itemize} \end{enumerate} \column{2.2in} \end{columns} \end{frame} \section{Preliminary results} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{Results in 2011 data} We can rewrite $Q$ in form: \begin{equation} Q=\sqrt{-2q_{\bot 1} q_{\bot 2}[cosh(y_1 -y_2)-cos(\phi_1-\phi_2)] } \end{equation} ,where $y_i$ are the pseudo-rapidity, $\phi_i$ are azimuthal angles. We see BEC \begin{columns} \column{1.6in} \includegraphics[scale=.2]{images/phi.png} \column{1.6in} \includegraphics[scale=.2]{images/rap.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \section{Three body correlations} \begin{frame}\frametitle{Generalization of two body correlations} Assuming no correlations in space the Wigner function can be expressed)analogy to eg.(2): \begin{equation} W(p_1,p_2,p_3,x_1,x_2,x_3)=\Omega_0(p_1,p_2,p_3)w(p_1,x_1)w(p_2,x_2)w(p_3,x_3) \end{equation} This leads to correlation function: \begin{small} \begin{align}\label{eq:two} %\begin{equation} C_3(p1,p2,p3)=\vert \widehat{w}(P_{12}, \Delta_{12}) \vert^2 + \vert \widehat{w}(P_{23}, \Delta_{23} ) \vert^2+\vert \widehat{w}(P_{31}, \Delta_{31} ) \vert^2 + \nonumber \\ 2 \mathcal{R}[\widehat{w}(P_{12}, \Delta_{12} ) \widehat{w}(P_{23}, \Delta_{23} )\widehat{w}(P_{31}, \Delta_{31} ) ] \end{align}\end{small} ,where $\Delta_{ij}=p_i-p_j$, and $\widehat{w}(P_{ij}, \Delta_{ij} )=\int dx_idx_j W(P_{ij}, x)e^{ix\Delta_{ij}}$ \end{frame} \begin{frame}\frametitle{Probing Cluster Model} \begin{columns} \column{3.2in} Let us consider simple ansatz: \begin{align}\label{eq:two} W(p_1,p_2,x_1,x_2)=\Omega_0(p_1,p_2)[V(x_1)V(x_2)\nonumber \\ +\alpha V_2(x_1,x_2)] \end{align} ,where $V(x)=\int \phi(x-X)V_c(X)dX$,\\ $V_2=\int V_c(X)\phi(x_1-X)\phi(x_2-X)dX$\\ \only<2> { $V_c(X)$ is the distribution of clusters in space.\\ $\phi(x-X)$ is the shape of the cluster. \\ $V(x_1)V(x_2)$ emission from two clusters. \\ $V_2(x_1,x_2)$ emission from single cluster. \\ } \column{1.6in} \includegraphics[scale=.15]{images/clusters.png} \end{columns} \end{frame} \begin{frame}\frametitle{Probing Cluster Model} \begin{columns} \column{3.2in} The correlation function for this ansatz takes form: \begin{equation} C(p_1,p_2)= \vert \widehat{V_c}(\Delta_{12}) \widehat{\phi}(\Delta_{12}) \vert^2 + \alpha \vert \widehat{\phi}(\Delta_{12}) \vert^2 \end{equation} where $\widehat{\phi}(\Delta_{12}) = \int dx \phi(x)e^{ix\Delta_12}$ \column{1.6in} \includegraphics[scale=.15]{images/clusters.png} \end{columns} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \section{Summary} \begin{frame}\frametitle{Conclusions} \begin{itemize} \item BEC clearly visible in data. \item Analysis systematically dominated. \item Enought events to perform first measurement of 3 body correlations. \end{itemize} \end{frame} \end{document}