\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} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 \definecolor{mygreen}{cmyk}{0.82,0.11,1,0.25} \usetheme{Sybila} \title[1D Bose-Einstein correlations]{1D Bose-Einstein correlations} \author{Marcin Chrz\k{a}szcz$^{1}$} \institute{$^1$~University of Zurich} \date{\today} \begin{document} % --------------------------- SLIDE -------------------------------------------- \frame[plain]{\titlepage} \author{Marcin Chrz\k{a}szcz{~}} \institute{(UZH)} % ------------------------------------------------------------------------------ % --------------------------- SLIDE -------------------------------------------- \begin{frame}\frametitle{Fast reminder} \begin{columns} \column{2.8in} \begin{itemize} \item HBT interferometry can be used to study the diameters of source. \item For indistinguishable particles the phenomena is know as Bose-Einstein Correlations(BEC). \item BEC correlations occur as enhancement of same particles in the low $Q$ region. \item We already observed the effects. \item For now I want to make BEC for pions, kaons are for future(less statistics). \item Use 2011 sample. \end{itemize} \column{2.2in} \includegraphics[height=3.cm,keepaspectratio]{images/HBT.png} \end{columns} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \end{frame} \begin{frame}\frametitle{Pre-Selection} \begin{center} \begin{tabular}{|c|c|} \hline & Cut \\ \hline \hline track $\chi^{2}$ & $< 2.6$ GeV \\ \hline track momentum & $> 3.0$ GeV \\ \hline track $p_{T}$ & $> 0.1$ GeV \\ \hline track IP & $< 0.2 \rm ~mm$ \\ \hline track IP $\chi^{2}$ & $< 2.6$ \\ \hline PID NN (pion, kaon) & $> 0.25$ \\ \hline track probability to be a ghost & $< 0.3$ \\ \hline \end{tabular} \end{center} \end{frame} \begin{frame}\frametitle{Selection} \begin{Large} Hard cuts, as we have enough statistics. \end{Large} \begin{center} \begin{tabular}{|c|c|} \hline & Cut \\ \hline \hline PID NN (pion, kaon)\footnote{No double counting with this cut} & $> 0.9$ \\ \hline track IP & $< 0.05 \rm ~mm$ \\ \hline track IP $\chi^2$ & $< 2$ \\ \hline track probability to be a ghost & $< 0.2$ \\ \hline n. PV & $== 1$ \\ \hline \end{tabular} \end{center} \end{frame} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{frame}\frametitle{How to measure correlations?} \begin{itemize} \item Define a correlations function: \end{itemize} \begin{equation} C(q_1, q_2) = \dfrac{\rho(q_1, q_2)}{\rho(q_1) \rho(q_2)} \end{equation} \begin{itemize} \item There are many kinematic variables where BEC can occur. Canonical choice $Q=\sqrt{-(q_1 -q_2)^2}$. \item $\rho(q_1, q_2)$ is easy. For each pair of same sign particles calculate Q and plot. \item $\rho(q_1) \rho(q_2)$ is a bit more tricky. One way is to take opposite sign particles or mix events. Both by construction kill the BEC effects. \end{itemize} \end{frame} \begin{frame}\frametitle{Opposite sign} \begin{columns} \column{2.5in} $Q$ Distribution. \includegraphics[width=0.9\textwidth]{images/q2.png} \column{2.5in} $C(q_1, q_2)$ Distribution. \includegraphics[width=0.9\textwidth]{images/corr.png} \end{columns} \begin{itemize} \item Here I just took $1\%$ of data not to bias myself afterwards. \item The same sign sample is not the perfect one as it has resonances inside. \end{itemize} \end{frame} \begin{frame}\frametitle{Mix sample} \begin{columns} \column{2.5in} $Q$ Distribution. \includegraphics[width=0.9\textwidth]{images/q2_mix.png} \column{2.5in} $C(q_1, q_2)$ Distribution. \includegraphics[width=0.9\textwidth]{images/corr_mix.png} \end{columns} \begin{itemize} \item Here I just took $1\%$ of data not to bias myself afterwards. \item Correlation looks much much better. \end{itemize} \end{frame} \begin{frame}\frametitle{To Do} \begin{itemize} \item Do double ration(take into account detector effects). \item DO systematics. \end{itemize} \end{frame} \end{document}