#include "hparticlebeamtilt.h"

// ROOT's IO and RTTI stuff is added here
ClassImp(HParticleBeamTilt)

//_HADES_CLASS_DESCRIPTION
////////////////////////////////////////////////////////////////////////////////
//
// Author   : Vladimir Pechenov
//
// HParticleBeamTilt
//
// This class keeps the beam tilt and beam energy information for Feb22 beamtime
// and has the functionality to correct the measured theta and phi angles by the beam tilt.
//
// To select the elastic pp events, it is important to know the beam energy and
// the beam direction (beam tilt).
// Beam energy for protons (not for the nucleus) can be higher than nominal (up to 1%).
// The tilt of the beam depends on the focusing procedure and may be different after each focusing.
//
// During Feb22 beamtime, the focusing of the beam was performed several times.
// As a result, six time ranges were determined and tilt parameters were calculated for them.
// Beam energy has been defined for two energies.
// They are 4.535 (instead of 4.5) GeV and 1.602 (instead of 1.58) GeV.
//
// How to use:
//
// #include "hparticlebeamtilt.h"
// ...
// // Before event loop:
//    HEventHeader *evHeader   = loop->getEventHeader();
//    HParticleBeamTilt beamTilt;
//    beamTilt.setEventHeader(evHeader);
// // From event header code take runId and select beam parameters for this event.
// ...
// // For each particle:
//    Double_t thDeg,phiDeg;                                                 // angles after correction by the beam tilt
//    beamTilt.correctAngles(cand->getTheta(),cand->getPhi(),thDeg,phiDeg);  // "cand" is HParticleCand
//
// ----------------------------------------------------------------------------
//    // Beam properties:
//    const TLorentzVector* beam = beamTilt.beamLVector();                         // return a beam four-momentum vector along
//                                                                           // the axis of the beam tilt (in lab.system)
//    if( beam != NULL) ...
//    beamTilt.beamMom();    // beam momentum
//    beamTilt.gamma2();     // (Ek+2*mp)/(2*mp);
//    beamTilt.beamEk();     // beam kinetic energy
//
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