
\documentclass[border=5pt,multi=true]{standalone}
\usepackage{standalone}
\usepackage{lineno}
\usepackage{graphicx}
\usepackage{xspace}
\usepackage{color}
\usepackage{colortbl}
\usepackage{amsmath}
\usepackage{ifthen}
\usepackage{ulem}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{upgreek}
\usepackage{hyperref}
\usepackage{hypcap}
\usepackage{rotating}
\usepackage{multirow}
\usepackage{graphpap}
\usepackage{subfigure}
\usepackage{wasysym}
\usepackage{array}
\usepackage{pifont}
\usepackage{cite}
\usepackage{mciteplus}


\graphicspath{{./figs/}}

\begin{document}
\DeclareGraphicsExtensions{.pdf}
\setlength{\unitlength}{1mm}
  \centering
  \begin{picture}(150,60)
    \put(0,0){
      \includegraphics*[width=75mm,height=60mm,%
      ]{Fig16a.pdf}
    }
    \put(75,0){
      \includegraphics*[width=75mm,height=60mm,%
      ]{Fig16b.pdf}
    }
    \put(35, 1)   { $\left|\Delta\phi\right|/\pi$}
    \put(112,1)   { $\left|\Delta y\right|$}
    \put(-2 , 38 )  { \small %
      \begin{sideways}%
        $\tfrac{\mathrm{d}\ln\sigma^*}{\mathrm{d}\left| \Delta\phi \right|}%
        ~\left[ \tfrac{\pi}{0.1}\right]$ 
      \end{sideways}%
    }
    \put(73, 37 )  { \small %
      \begin{sideways}%
        $\tfrac{\mathrm{d}\ln\sigma^*}{\mathrm{d}\left|\Delta y\right|}%
        ~\left[ \tfrac{1}{0.1}\right]$
      \end{sideways}%
    }
    \put( 12,45){ \small %
      LHCb
    }
    \put(130,45){ \small %
      LHCb
    }
    \put( 13,52)   { a) }
    \put(140,52)   { b) }
    \put(50,50){ \tiny
      $\begin{array}{cl}
        {\color{red}     \text{\ding{108}} } & \ensuremath{\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace{}\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace}\xspace  \\
        {\color{blue}    \text{\ding{110}} } & \ensuremath{\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace{}\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^+}\xspace}\xspace  
       \end{array}$
    } 
    \put(90,50){ \tiny
      $\begin{array}{cl}
        {\color{red}     \text{\ding{108}} } & \ensuremath{\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace{}\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace}\xspace  \\
        {\color{blue}    \text{\ding{110}} } & \ensuremath{\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^0}\xspace{}\ensuremath{\ensuremath{\ensuremath{D}\xspace}\xspace^+}\xspace}\xspace  
       \end{array}$
    } 
  \end{picture}
\end{document}
