PXDUtilities.h

/**************************************************************************
 * BASF2 (Belle Analysis Framework 2)                                     *
 * Copyright(C) 2021  Belle II Collaboration                              *
 *                                                                        *
 * Author: The Belle II Collaboration                                     *
 * Contributors: Qingyuan Liu                                             *
 *                                                                        *
 * This software is provided "as is" without any warranty.                *
 **************************************************************************/
 
#pragma once
 
#include <framework/gearbox/Unit.h>
#include <framework/gearbox/Const.h>
#include <tracking/dataobjects/RecoTrack.h>
#include <genfit/MeasuredStateOnPlane.h>
#include <TVector3.h>
//#include <limits>
#include <math.h>
 
namespace Belle2 {
  namespace PXD {
 
    const int Z_Si = 14; 
    const double A_Si = 28.085; 
    const double rho_Si = 2.3290 * Unit::g_cm3; 
    inline double xiBeta2_L(const int Z = Z_Si,
                            const double A = A_Si,
                            const double rho = rho_Si,
                            const int z = 1)
    {
      const double K = 0.307075 * Unit::MeV * pow(Unit::cm, 2);
      return K / 2 * Z / A * z * z * rho;
    }
 
    inline double hbarWp(const int Z = Z_Si,
                         const double A = A_Si,
                         const double rho = rho_Si)
    {
      return std::sqrt(rho * Z / A) * 28.816 * Unit::eV;
    }
 
    inline double getDeltaP(const double mom, const double length, const double mass = Const::electronMass)
    {
      double betaGamma = mom / mass;
      if (betaGamma <= 100) return 0.0; // requirement of the formula.
      double beta2 = 1. / (1. + 1. / betaGamma / betaGamma);
      double xi = xiBeta2_L() * length / beta2;
      return xi * log(2 * mass * xi / pow(hbarWp(), 2) + 0.2);
    }
 
    inline unsigned short getPXDModuleID(const VxdID& sensorID)
    {
      return sensorID.getLayerNumber() * 1000 +
             sensorID.getLadderNumber() * 10 +
             sensorID.getSensorNumber();
    }
 
    inline VxdID getVxdIDFromPXDModuleID(const unsigned short& id)
    {
      return VxdID(id / 1000, (id % 1000) / 10, id % 10);
    }
 
    typedef genfit::MeasuredStateOnPlane TrackState;
    std::shared_ptr<TrackState> getTrackStateOnModule(const VXD::SensorInfoBase& pxdSensorInfo,
                                                      RecoTrack& recoTrack, double lambda = 0.0);
 
  } // end namespace PXD
} // end namespace Belle2