% Author: Izaak Neutelings (July 2017)
% Description: Detector (tracker, ECAL, HCAL) signatures of hadronic tau decay, incl. intermediate resonances.
% Source: Inspiration from Takahashi & Tomoto (2012) [http://cds.cern.ch/record/1514540, Fig. 3.14, p. 37].
 
\documentclass{article}
\usepackage{amsmath} % for \text
\usepackage{tikz}
\tikzset{>=latex} % for LaTeX arrow head
%\definecolor{mylightred}{RGB}{255,200,200}
%\definecolor{mylightblue}{RGB}{172,188,63}
%\definecolor{mylightgreen}{RGB}{150,220,150}
 
% split figures into pages
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{1pt}%
 
% vertical custom shading
%https://tex.stackexchange.com/questions/191735/is-it-possible-to-define-the-position-of-top-bottom-and-middle-color-in-fill
\makeatletter
\tikzset{vertical custom shading/.code={%
  \pgfmathsetmacro\tikz@vcs@middle{#1}
  \pgfmathsetmacro\tikz@vcs@bottom{\tikz@vcs@middle/2}
  \pgfmathsetmacro\tikz@vcs@top{(100-\tikz@vcs@middle)/2+\tikz@vcs@middle}
  \pgfdeclareverticalshading[tikz@axis@top,tikz@axis@middle,tikz@axis@bottom]{newaxis}{100bp}{%
    color(0bp)=(tikz@axis@bottom);
    color(\tikz@vcs@bottom bp)=(tikz@axis@bottom);
    color(\tikz@vcs@middle bp)=(tikz@axis@middle);
    color(\tikz@vcs@top bp)=(tikz@axis@top);
    color(100bp)=(tikz@axis@top)}
    \pgfkeysalso{/tikz/shading=newaxis}
  }
}
\makeatother
 
\begin{document}
 
 
 
% arrow style
\usetikzlibrary{decorations.markings}
\tikzset{->-/.style={decoration={markings,
                               mark=at position .7 with {\arrow{>}}},
                               postaction={decorate}}}
 
% photon
\usetikzlibrary{decorations.pathmorphing}
\tikzset{photon/.style={decorate, decoration={snake,segment length=5,amplitude=1.1}}}
 
% cone style
\usetikzlibrary{shadows.blur}
\tikzset{mycone/.pic={
       \shadedraw[top color=white, bottom color=black!50,shading angle=50,vertical custom shading=10]
                    (-0.4,0.99) -- (0,0) -- (0.4,0.99);
       \shadedraw[top color=white, bottom color=black!20,shading angle=90]
                    (0,1) ellipse (0.4 and 0.12);}};
 
 
 
% TAU DECAY MODES
\begin{tikzpicture}[scale=0.9]
 
  \large
  \def\R{120}            % inner radius
  \def\hca{5}            % half central angle
  \def\hcl{\R*sin(\hca)} % half chord length c = 2Rsin(theta/2)
  \def\tracker{3}        % tracker
  \def\ECAL{4.8}         % ECAL
  \def\HCAL{7.2}         % HCAL
  \def\hclmax{(\R+\HCAL)*sin(\hca)} % mac
 
  % detectors
  \foreach \r in {\tracker,\ECAL,\HCAL}{
    \draw[thick] (0,\r) arc (90:90-\hca:\R+\r)
                 (0,\r) arc (90:90+\hca:\R+\r);
  }
  \node[left=0,above left] at ({1.08*\hclmax},{0.10*\tracker}) {tracker};
  \node[left=0,above left] at ({1.08*\hclmax},\tracker) {ECAL};
  \node[left=0,above left] at ({1.08*\hclmax},\ECAL) {HCAL};
 
 
  % DM 0
  \begin{scope}[shift={({-0.79*\hcl},0)}, rotate=6]
    \node[below] at (0,0) {$\tau^\pm$};
    \node[below=18] at (0,0) {$\tau^\pm\to\pi^\pm\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-30] % neutrinos
      (tau) -- +(0,1.3) node[right=6pt,above] {$\nu_\tau$};
    \draw[->-,       thick,rotate=12] % pion
      (tau) -- +(0,3.9) node[left=10,above=38] {$\pi^\pm$}
      pic[rotate=20,scale=1.2] {mycone};
  \end{scope}
 
  % DM 1
  \begin{scope}[shift={({-0.44*\hcl},0)}, rotate=1]
    \node[below] at (0,0) {$\tau^\pm$};
    \node[right=8pt,below=18] at (0,0) {$\tau^\pm\to\rho^\pm\nu_\tau\to\pi^\pm\pi^0\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-45] % neutrinos
      (tau) -- +(0,1.5) node[above right] {$\nu_\tau$};
    \draw[->-,       thick,rotate= 15] % rho
      (tau) -- +(0,0.7) coordinate (rho) node[midway,left] {$\rho^\pm$};
    \draw[->-,       thick,rotate= 24] % pion
      (rho) -- +(0,3.4) node[left=15,above=38] {$\pi^\pm$}
      pic[rotate=22,scale=1.2] {mycone};
    \draw[->-,densely dashed,thick,rotate=-18] % pion0
      (rho) -- +(0,0.7) coordinate (pion0) node[midway,right] {$\pi^0$};
    \draw[photon,rotate=10] % photon 1
      (pion0) -- +(0,0.9) node[left=8,above=32] {$\gamma$}
      pic[rotate=11.5,xscale=0.8] {mycone};
    \draw[photon,rotate=-30] % photon 2
      (pion0) -- +(0,1.0) node[right=15,above=30] {$\gamma$}
      pic[rotate=-24,xscale=0.8] {mycone};
  \end{scope}
 
  % DM 2
  \begin{scope}[shift={({0.09*\hcl},0)}, rotate=-3]
    \node[below] (0,0) {$\tau^\pm$};
    \node[right=14pt,below=18] at (0,0) {$\tau^\pm\to\text{a}_1^\pm\nu_\tau\to\pi^\pm\pi^0\pi^0\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-50] % neutrinos
      (tau) -- +(0,1.5) node[above right] {$\nu_\tau$};
    \draw[->-,       thick,rotate= 20] % a1
      (tau) -- +(0,0.5) coordinate (a1) node[midway,left] {$\text{a}_1^\pm$};
    \draw[->-,       thick,rotate= 34] % rho
      (a1)  -- +(0,0.8) coordinate (rho) node[midway,left] {$\rho^\pm$};
    \draw[->-,       thick,rotate= 38] % pion
      (rho) -- +(0,3.5) node[left=15,above=38] {$\pi^\pm$}
      pic[rotate=22,scale=1.2] {mycone};
    \draw[->-,densely dashed,thick,rotate=-35] % pion0
      (a1)  -- +(0,0.8) coordinate (pion01) node[midway,right] {$\pi^0$};
    \draw[->-,densely dashed,thick,rotate=-14] % pion0
      (rho) -- +(0,0.6) coordinate (pion02) node[midway,right] {$\pi^0$};
    \draw[photon,rotate= 26] % photon 1
      (pion02) -- +(0,0.6) node[left=8,above=32] {$\gamma$}
      pic[rotate=11.5,xscale=0.8] {mycone};
    \draw[photon,rotate=-20] % photon 2
      (pion02) -- +(0,0.6) node[right=12,above=32] {$\gamma$}
      pic[rotate=-22,xscale=0.8] {mycone};
    \draw[photon,rotate=-24] % photon 3
      (pion01) -- +(0,1.3) node[right=10,above=32] {$\gamma$}
      pic[rotate=-20,xscale=0.8] {mycone};
    \draw[photon,rotate=-46] % photon 4
      (pion01) -- +(0,1.8) node[right=25,above=26] {$\gamma$}
      pic[rotate=-36,xscale=0.8] {mycone};
  \end{scope}
 
  % DM 10
  \begin{scope}[shift={({0.64*\hcl},0)}, rotate=-10]
    \node[below] (0,0) {$\tau^\pm$};
    \node[right=14pt,below=18] at (0,0) {$\tau^\pm\to\text{a}_1^\pm\nu_\tau\to\pi^\pm\pi^\mp\pi^\pm\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-50] % neutrinos
      (tau) -- +(0,1.5) node[above right] {$\nu_\tau$};
    \draw[->-,       thick,rotate= 20] % a1
      (tau) -- +(0,0.5) coordinate (a1) node[midway,left] {$\text{a}_1^\pm$};
    \draw[->-,       thick,rotate= 34] % rho
      (a1)  -- +(0,0.8) coordinate (rho) node[midway,left] {$\rho^0$};
    \draw[->-,       thick,rotate= 36] % pion 1
      (rho) -- +(0,3.0) node[left=10,above=38] {$\pi^\pm$}
      pic[rotate=20,scale=1.2] {mycone};
    \draw[->-,       thick,rotate= -5] % pion 2
      (rho) -- +(0,2.7) node[right=15,above=38] {$\pi^\mp$}
      pic[rotate=-15,scale=1.2] {mycone};
    \draw[->-,       thick,rotate=-24] % pion 3
      (a1)  -- +(0,3.9) node[right=29,above=33] {$\pi^\pm$}
      pic[rotate=-38,scale=1.2] {mycone};
  \end{scope}
 
\end{tikzpicture}
 
 
 
% TAU DECAY MODES - DM 1 only
\begin{tikzpicture}[scale=0.9]
 
  \large
%  % arrow style
%  \usetikzlibrary{decorations.markings}
%  \tikzset{->-/.style={decoration={markings,
%                                   mark=at position .7 with {\arrow{>}}},
%                                   postaction={decorate}}}
 
  % photon
  \usetikzlibrary{decorations.pathmorphing}
  \tikzset{photon/.style={decorate, decoration={snake,segment length=5,amplitude=1.1}}}
 
  % cone style
  \usetikzlibrary{shadows.blur}
  \tikzset{mycone/.pic={
           \shadedraw[top color=white, bottom color=black!50,shading angle=50,vertical custom shading=10]
                        (-0.4,0.99) -- (0,0) -- (0.4,0.99);
           \shadedraw[top color=white, bottom color=black!20,shading angle=90]
                        (0,1) ellipse (0.4 and 0.12);}};
 
  \def\R{10}             % inner radius
  \def\hca{12}           % half central angle
  \def\hcl{\R*sin(\hca)} % half chord length c = 2Rsin(theta/2)
  \def\tracker{3}        % tracker
  \def\ECAL{4.8}         % ECAL
  \def\HCAL{7.2}         % HCAL
  \def\hclmax{(\R+\HCAL)*sin(\hca)} % mac
 
  % detectors
  \foreach \r in {\tracker,\ECAL,\HCAL}{
    \draw[thick] (0,\r) arc (90:90-\hca:\R+\r)
                 (0,\r) arc (90:90+\hca:\R+\r);
  }
  \node[left=0,above left] at ({1.1*\hclmax},{0.10*\tracker}) {tracker};
  \node[left=0,above left] at ({1.1*\hclmax},\tracker) {ECAL};
  \node[left=0,above left] at ({1.1*\hclmax},\ECAL) {HCAL};
 
  % DM 1
  \begin{scope}[shift={(0,0)}, rotate=0]
    \node[below] at (0,0) {$\tau^\pm$};
    \node[right=8pt,below=18] at (0,0) {$\tau^\pm\to\rho^\pm\nu_\tau\to\pi^\pm\pi^0\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-45] % neutrinos
      (tau) -- +(0,1.5) node[above right] {$\nu_\tau$};
    \draw[->-,       thick,rotate= 15] % rho
      (tau) -- +(0,0.7) coordinate (rho) node[midway,left] {$\rho^\pm$};
    \draw[->-,       thick,rotate= 24] % pion
      (rho) -- +(0,3.4) node[left=15,above=38] {$\pi^\pm$}
      pic[rotate=22,scale=1.2] {mycone};
    \draw[->-,densely dashed,thick,rotate=-18] % pion0
      (rho) -- +(0,0.7) coordinate (pion0) node[midway,right] {$\pi^0$};
    \draw[photon,rotate= 10] % photon 1
      (pion0) -- +(0,0.9) node[left=8,above=32] {$\gamma$}
      pic[rotate=11.5,xscale=0.8] {mycone};
    \draw[photon,rotate=-30] % photon 2
      (pion0) -- +(0,1.0) node[right=15,above=30] {$\gamma$}
      pic[rotate=-24,xscale=0.8] {mycone};
  \end{scope}
 
\end{tikzpicture}
 
 
 
% TAU DECAY MODES - DM 10 only
\begin{tikzpicture}[scale=0.9]
 
  \large
 
  % photon
  \usetikzlibrary{decorations.pathmorphing}
  \tikzset{photon/.style={decorate, decoration={snake,segment length=5,amplitude=1.1}}}
 
  % cone style
  \usetikzlibrary{shadows.blur}
  \tikzset{mycone/.pic={
           \shadedraw[top color=white, bottom color=black!50,shading angle=50,vertical custom shading=10]
                        (-0.4,0.99) -- (0,0) -- (0.4,0.99);
           \shadedraw[top color=white, bottom color=black!20,shading angle=90]
                        (0,1) ellipse (0.4 and 0.12);}};
 
  \def\R{10}             % inner radius
  \def\hca{14}           % half central angle
  \def\hcl{\R*sin(\hca)} % half chord length c = 2Rsin(theta/2)
  \def\tracker{3}        % tracker
  \def\ECAL{4.8}         % ECAL
  \def\HCAL{7.2}         % HCAL
  \def\hclmax{(\R+\HCAL)*sin(\hca)} % mac
 
  % detectors
  \foreach \r in {\tracker,\ECAL,\HCAL}{
    \draw[thick] (0,\r) arc (90:90-\hca:\R+\r)
                 (0,\r) arc (90:90+\hca:\R+\r);
  }
  \node[left=0,above left] at ({1.1*\hclmax},{0.10*\tracker}) {tracker};
  \node[left=0,above left] at ({1.1*\hclmax},\tracker) {ECAL};
  \node[left=0,above left] at ({1.1*\hclmax},\ECAL) {HCAL};
 
  % DM 10
  \begin{scope}[shift={(0,0)}, rotate=-3]
    \node[below] (0,0) {$\tau^\pm$};
    \node[right=14pt,below=18] at (0,0) {$\tau^\pm\to\text{a}_1^\pm\nu_\tau\to\pi^\pm\pi^\mp\pi^\pm\nu_\tau$};
    \draw[->-,thick]                   % tau
      (0,0) -- (0,0.7) coordinate (tau);
    \draw[->-,dotted,thick,rotate=-50] % neutrinos
      (tau) -- +(0,1.5) node[above right] {$\nu_\tau$};
    \draw[->-,       thick,rotate= 20] % a1
      (tau) -- +(0,0.5) coordinate (a1) node[midway,left] {$\text{a}_1^\pm$};
    \draw[->-,       thick,rotate= 34] % rho
      (a1)  -- +(0,0.8) coordinate (rho) node[midway,left] {$\rho^0$};
    \draw[->-,       thick,rotate= 36] % pion 1
      (rho) -- +(0,3.0) node[left=10,above=38] {$\pi^\pm$}
      pic[rotate=30,scale=1.2] {mycone};
    \draw[->-,       thick,rotate= -5] % pion 2
      (rho) -- +(0,2.7) node[right=15,above=38] {$\pi^\mp$}
      pic[rotate=-5,scale=1.2] {mycone};
    \draw[->-,       thick,rotate=-24] % pion 3
      (a1)  -- +(0,3.9) node[right=29,above=33] {$\pi^\pm$}
      pic[rotate=-28,scale=1.2] {mycone};
  \end{scope}
 
\end{tikzpicture}
 
 
 
\end{document}