THaBeamInfo.cxx

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//*-- Author :    Ole Hansen   27-Apr-04
 
//
// THaBeamInfo
//
// Utility class/structure for holding variable beam information.
//
 
#include "THaBeamInfo.h"
#include "THaBeam.h"
#include "THaRunParameters.h"
#include "TMath.h"
 
using namespace std;
 
//_____________________________________________________________________________
Double_t THaBeamInfo::GetE() const
{
  // Return beam energy. This is the energy corresponding to the
  // current beam momentum and mass, not necessarily the same as
  // the nominal beam energy in the run database.
 
  if( !fBeam )
    return kBig;
 
  Double_t m = GetM();
  Double_t p = GetP();
  return TMath::Sqrt( p*p + m*m );
}
 
//_____________________________________________________________________________
Double_t THaBeamInfo::GetM() const
{
  // Return mass of beam particles
 
  if( !fBeam )
    return kBig;
  THaRunParameters* rp = fBeam->GetRunParameters();
  if( !rp )
    return kBig;
  return rp->GetBeamM();
}
 
//_____________________________________________________________________________
Int_t THaBeamInfo::GetQ() const
{
  // Return charge of beam particles (electrons: -1)
 
  if( !fBeam )
    return 0;
  THaRunParameters* rp = fBeam->GetRunParameters();
  if( !rp )
    return 0;
  return rp->GetBeamQ();
}
 
//_____________________________________________________________________________
Double_t THaBeamInfo::GetdE() const
{
  // Return beam energy uncertainty
 
  if( !fBeam )
    return kBig;
  THaRunParameters* rp = fBeam->GetRunParameters();
  if( !rp )
    return kBig;
  return rp->GetBeamdE();
}
 
//_____________________________________________________________________________
ClassImp(THaBeamInfo)