Updated the calculation of the angle between dimuon and event plane

Author: kkimura0623

PWGDQ/Core/VarManager.cxx

@@ -916,6 +916,8 @@ void VarManager::SetDefaultVarNames()
   fgVariableUnits[kCosThetaCS] = "";
   fgVariableNames[kPhiCS] = "#varphi_{CS}";
   fgVariableUnits[kPhiCS] = "rad.";
+  fgVariableNames[kCosPhiVP] = "cos(#varphi_{VP} - #Psi_{2})";
+  fgVariableUnits[kCosPhiVP] = "";
   fgVariableNames[kPhiVP] = "#varphi_{VP} - #Psi_{2}";
   fgVariableUnits[kPhiVP] = "rad.";
   fgVariableNames[kDeltaPhiPair2] = "#Delta#phi";