TTTT2/docs/presentation_2018_01_25/main.tex

\documentclass[english,aspectratio=43,8pt]{beamer}
\usepackage{graphicx}
\usepackage{amssymb}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage{subcaption}
\usepackage{marvosym}
\usepackage{verbatim}
\usepackage[normalem]{ulem}  % Needed for /sout

\newcommand{\pb}{\si{\pico\barn}}%
\newcommand{\fb}{\si{\femto\barn}}%
\newcommand{\invfb}{\si{\per\femto\barn}}
\newcommand{\GeV}{\si{\giga\electronvolt}}

\hypersetup{colorlinks=true,urlcolor=blue}

\usetheme[]{bjeldbak}

% Note: Z-veto wouldn't really work for Z->tautau

\begin{document}

    \title[]{Adding Tau Leptons to TTTT X-Section Measurement}
    \author[C. Fangmeier]{\textbf{Caleb Fangmeier}}
    \institute[UNL]{University of Nebraska \-- Lincoln}
    \date{TTTT Working Meeting | January 25, 2018}

    \titlegraphic{%
    \begin{figure}
        \includegraphics[width=1in]{CMSlogo.png}\hspace{0.75in}\includegraphics[width=1in]{nebraska-n.png}
    \end{figure}
    }

    \begin{frame}[plain]
        \titlepage
        %
    \end{frame}

    \begin{frame}{Introduction}
        \begin{itemize}
            \item \textbf{Goal:} Investigate how the TTTT cross-section measurement could be improved by adding taus to the lepton selection.
            \item To avoid the work of modifying the existing analysis looper to include taus, a simple ``mock''\footnote{\url{https://github.com/cfangmeier/FTAnalysis/tree/tau_studies/studies/tau}} analysis was implemented from scratch which attempts to replicate the main features of the real analysis.
            \item Runs on same \texttt{CMS4} nTuples as existing analysis.
        \end{itemize}
    \end{frame}

    \begin{frame}{Mock Analysis 2016 Yields}
        \begin{columns}
            \begin{column}{0.4\textwidth}
                \begin{itemize}
                    \item Attempt to replicate AN yields with mock analysis using only electrons and muons
                    \item Generally overestimate yield (wrt analysis note)by 10-30\%. (However this doesn't include any scale factors)
                    \item But shapes tend to match, so go ahead and add taus to make a comparison.
                    \item All data normalized to 35.9 $\mathrm{fb}^{-1}$.
                \end{itemize}
            \end{column}
            \begin{column}{0.59\textwidth}
                \includegraphics[width=\textwidth]{figures/Yield_Ignoring_Taus.png}
            \end{column}
        \end{columns}
    \end{frame}

    \begin{frame}{Tau Selection}
        \begin{itemize}
            \item Taus to be considered in the SS pair must pass the following requirements
            \begin{itemize}
                \item Pass the ID: \texttt{byTightIsolationMVArun2v1DBdR03oldDMwLT}
                \item Have $P_{T}>20$GeV
                \item Isolated ($dR>0.4$) from any electrons or muons that pass their respective selection criteria
            \end{itemize}
            \item Generator-Level taus used in truth-matching must:
            \begin{itemize}
                \item Be flagged as prompt (ie. \texttt{tas::genps\_fromHardProcessDecayed()==1})
                \item Decay hadronically ($\tau^\pm \rightarrow\pi^\pm \{\pi_0\}$, $\tau^\pm \rightarrow\pi^\pm\pi^\pm\pi^\mp\{\pi_0\}$)
            \end{itemize}
            \item A reconstructed tau is considered truth-matched if it is within $dR<0.3$ of a generator-level tau
            \item Otherwise taus are treated exactly the same as electrons and muons in the SS-pair construction/Z-Veto/Jet-Cleaning.
        \end{itemize}
    \end{frame}


    \begin{frame}{Yields/Truth Matching}
        \begin{columns}
            \begin{column}{0.5\textwidth}
                \includegraphics[width=\textwidth]{figures/Yield_For_events_with_0_Tau.png}
            \end{column}
            \begin{column}{0.5\textwidth}
                \includegraphics[width=\textwidth]{figures/Yield_For_events_with_1_Tau.png}
            \end{column}
        \end{columns}
        \begin{itemize}
            \item Above figures show yields when there are zero selected taus(left) or one selected tau(right).
            \item Orange Lines show yields when the tau is required to be truth-matched.
            \item About 60\% of taus are fakes!
            \item Adding taus is clearly not helpful at all in SS regions(1-6), but maybe helpful in multi-lepton regions(7-8)
        \end{itemize}
    \end{frame}

    \begin{frame}{Cross-Checking Truth Matching}
        \begin{columns}
            \begin{column}{0.4\textwidth}
                \begin{itemize}
                    \item Previous slide indicates $\approx60-70$\% of taus are fakes.
                    \item Figure shows the yields for events in any SR broken down by \# of generator-level taus and \# of selected taus.
                    \item The figure on the right corroborates the previous slide; In TTTT, for example, only about 40\% of events with 1 selected tau have 1 or more real taus.
                \end{itemize}
            \end{column}
            \begin{column}{0.6\textwidth}
                \includegraphics[width=\textwidth]{figures/Generated_tau_vs_Selected_tau.png}
            \end{column}
        \end{columns}
    \end{frame}

    \begin{frame}{Results with Expanded Binning}
        \begin{columns}
            \begin{column}{0.5\textwidth}
                \includegraphics[width=\textwidth]{figures/Yield_For_events_with_0_Tau_NewSR.png}
            \end{column}
            \begin{column}{0.5\textwidth}
                \includegraphics[width=\textwidth]{figures/Yield_For_events_with_1_Tau_NewSR.png}
            \end{column}
        \end{columns}
        \begin{itemize}
            \item Ongoing investigation of more fine binning\footnote{\url{https://github.com/cfangmeier/FTAnalysis/blob/tau\_studies/studies/tau/Yield.C#L261}}.
            \item Same conclusions: SS show no gain, and multilepton may give marginal improvements
        \end{itemize}
    \end{frame}

    \begin{frame}{Conclusions}
        \begin{itemize}
            \item Investigated any benefit to including taus in measurement.
            \item With current tau selection no gain in SS
            \item Possibly very small (few percent) gain in multilepton categories
            \item Large amount of work needed to create data-driven estimate of fake-tau background
            \item Propose to document this and shelve it for now
        \end{itemize}
    \end{frame}

    \begin{frame}{Backup - Tau Reco Performance}
        \begin{columns}
            \begin{column}{0.5\textwidth}
                \begin{figure}
                    \includegraphics[width=\textwidth]{figures/Tau_Efficiency.png}
                \end{figure}
                \centering
                Tau Selection Efficiency (reco + id + $P_T>20\mathrm{GeV}$)
            \end{column}
            \begin{column}{0.5\textwidth}
                \begin{figure}
                    \includegraphics[width=\textwidth]{figures/Tau_Purity.png}
                \end{figure}
                \centering
                Tau Purity (matched w/ generator-level tau at $\delta R<0.3$)
            \end{column}
        \end{columns}
    \end{frame}

    \begin{frame}{Backup - Truth Matching Identity}
        \begin{figure}
            \includegraphics[width=\textwidth]{figures/Truth_Matching.png}
        \end{figure}
        \centering
        Tau Selection Efficiency (reco + id + $P_T>20\mathrm{GeV}$)
        \begin{itemize}
            \item \textbf{Note: } The flag for picking generator final state particles doesn't actually include the hadronic particles so it's likely that many of the ``Nothing'' taus really belong in the ``Hadron'' category. (Will be fixed in future)
        \end{itemize}
    \end{frame}

\end{document}