Simulation::GenEventBeamEffectBooster Class Reference

This tool takes a HepMC::GenEvent and applies boosts due to beam tilt, etc. More...

#include <GenEventBeamEffectBooster.h>

Inheritance diagram for Simulation::GenEventBeamEffectBooster:

Collaboration diagram for Simulation::GenEventBeamEffectBooster:

Public Member Functions
	GenEventBeamEffectBooster (const std::string &t, const std::string &n, const IInterface *p)
	Constructor with parameters.
StatusCode	initialize () override final
	Athena algtool's Hooks.
StatusCode	finalize () override final
	Athena algtool's Hooks.
StatusCode	initializeAthenaEvent ()
StatusCode	manipulate (HepMC::GenEvent &ge, const EventContext &ctx) const override final
	modifies the given GenEvent

Private Member Functions
StatusCode	initializeGenEvent (CLHEP::HepLorentzRotation &transform, const EventContext &ctx) const
	calculate the transformations that we want to apply to the particles in the current GenEvent
void	boostParticle (HepMC::GenParticlePtr &p, const CLHEP::HepLorentzRotation &transform) const
	apply boost to individual GenParticles

Private Attributes
ServiceHandle< IAthRNGSvc >	m_rndGenSvc {this, "RandomSvc", "AthRNGSvc"}
ATHRNG::RNGWrapper *m_randomEngine	ATLAS_THREAD_SAFE {}
	Slot-local RNG.
Gaudi::Property< std::string >	m_randomEngineName {this, "RandomStream", "BEAM"}
	Name of the random number stream.
Gaudi::Property< bool >	m_applyBoost {this, "ApplyBoost", true}
Gaudi::Property< bool >	m_applyDivergence {this, "ApplyDivergence", true}
Gaudi::Property< double >	m_sigma_px_b1 {this, "Sigma_px_b1", 20.e-6, "angular divergence in x of beam 1 [rad]"}
Gaudi::Property< double >	m_sigma_px_b2 {this, "Sigma_px_b2", 21.e-6, "angular divergence in x of beam 2 [rad]"}
Gaudi::Property< double >	m_sigma_py_b1 {this, "Sigma_py_b1", 22.e-6, "angular divergence in y of beam 1 [rad]"}
Gaudi::Property< double >	m_sigma_py_b2 {this, "Sigma_py_b2", 23.e-6, "angular divergence in y of beam 2 [rad]"}
Gaudi::Property< double >	m_xing_x_b1 {this, "HalfXing_x_b1", 19.e-6, "half-crossing in x for beam 1 at IP1, i.e. angle between beam 1 and z-axis"}
Gaudi::Property< double >	m_xing_x_b2 {this, "HalfXing_x_b2", 1.e-6, "half-crossing in x for beam 2 at IP1, i.e. angle between beam 2 and z-axis"}
Gaudi::Property< double >	m_xing_y_b1 {this, "HalfXing_y_b1", 150.e-6, "half-crossing in y for beam 1 at IP1, i.e. angle between beam 1 and z-axis"}
Gaudi::Property< double >	m_xing_y_b2 {this, "HalfXing_y_b2", -152.e-6, "half-crossing in y for beam 2 at IP1, i.e. angle between beam 2 and z-axis"}
Gaudi::Property< double >	m_dE {this, "deltaEOverE", 1.1E-4, "Delta_E/E theoretical value"}
Gaudi::Property< double >	m_pbeam1 {this, "pbeam1", 3500.0E3, "Beam 1 Momentum / MeV"}
Gaudi::Property< double >	m_pbeam2 {this, "pbeam2", 3500.0E3, "Beam 2 Momentum / MeV"}
Gaudi::Property< double >	m_beam1ParticleMass {this, "Beam1ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 1"}
Gaudi::Property< double >	m_beam2ParticleMass {this, "Beam2ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 2"}

Detailed Description

This tool takes a HepMC::GenEvent and applies boosts due to beam tilt, etc.

based on: https://svnweb.cern.ch/trac/atlasoff/browser/Simulation/G4Atlas/G4AtlasUtilities/trunk/src/BeamEffectTransformation.cxx

Definition at line 38 of file GenEventBeamEffectBooster.h.

Constructor & Destructor Documentation

GenEventBeamEffectBooster()

Simulation::GenEventBeamEffectBooster::GenEventBeamEffectBooster	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p )

Constructor with parameters.

Constructor.

Definition at line 23 of file GenEventBeamEffectBooster.cxx.

    : base_class(t,n,p)
  {
  }

Member Function Documentation

boostParticle()

void Simulation::GenEventBeamEffectBooster::boostParticle ( HepMC::GenParticlePtr & p, const CLHEP::HepLorentzRotation & transform ) const

private

apply boost to individual GenParticles

Definition at line 151 of file GenEventBeamEffectBooster.cxx.

  {
    // Apply the same transformation for EVERY HepMC::GenParticle
    const HepMC::FourVector &mom = p->momentum();
    CLHEP::HepLorentzVector hv(mom.px(), mom.py(), mom.pz(), mom.e()); //TODO check units
    ATH_MSG_VERBOSE("BEAMBOOST initial momentum " << hv );
    hv.transform(transform);
    ATH_MSG_VERBOSE("BEAMBOOST transformed momentum " << hv);
    p->set_momentum(HepMC::FourVector(hv.px(),hv.py(),hv.pz(),hv.e())); //TODO check units
  }

finalize()

StatusCode Simulation::GenEventBeamEffectBooster::finalize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 47 of file GenEventBeamEffectBooster.cxx.

  {
    ATH_MSG_VERBOSE("Finalizing ...");
    return StatusCode::SUCCESS;
  }

initialize()

StatusCode Simulation::GenEventBeamEffectBooster::initialize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 32 of file GenEventBeamEffectBooster.cxx.

  {
    ATH_MSG_VERBOSE("Initializing ...");
    // prepare the RandonNumber generation
    ATH_CHECK(m_rndGenSvc.retrieve());
    m_randomEngine = m_rndGenSvc->getEngine(this, m_randomEngineName); //FIXME
    if (!m_randomEngine) {
      ATH_MSG_ERROR("Could not get random number engine from RandomNumberService. Abort.");
      return StatusCode::FAILURE;
    }
    return StatusCode::SUCCESS;
  }

initializeAthenaEvent()

StatusCode Simulation::GenEventBeamEffectBooster::initializeAthenaEvent

(

)

Definition at line 53 of file GenEventBeamEffectBooster.cxx.

  {
    // Refresh properties retrieved from the BeamCondSvc here if
    // necessary.  It may be more thread-safe to retrieve them directly
    // from the BeamCondSvc during initializeGenEvent though?
 
    // m_sigma_px_b1 = 20.E-6; // angular divergence in x of beam 1 [rad]
    // m_sigma_px_b2 = 21.E-6; // angular divergence in x of beam 2 [rad]
    // m_sigma_py_b1 = 22.E-6; // angular divergence in y of beam 1 [rad]
    // m_sigma_py_b2 = 23.E-6; // angular divergence in y of beam 2 [rad]
    // // Crossing angles, note the convention here is taken from online https://atlas-dcs.cern.ch/index.php?page=LHC_INS::INS_BPM
    // m_xing_x_b1 = 19.E-6;   // half-crossing in x for beam 1 at IP1, i.e. angle between beam 1 and z-axis
    // m_xing_x_b2 = 1.E-6;    // half-crossing in x for beam 2 at IP1, i.e. angle between beam 2 and z-axis
    // m_xing_y_b1 =  150.E-6;  // half-crossing in y for beam 1 at IP1, i.e. angle between beam 1 and z-axis
    // m_xing_y_b2 = -152.E-6; // half-crossing in y for beam 2 at IP1, i.e. angle between beam 2 and z-axis
    // m_dE = 1.1E-4; // Delta_E/E theoretical value
    // m_pbeam1 = 3500.0E3; /// @todo Get from a service
    // m_pbeam2 = 3500.0E3; /// @todo Get from a service
    // m_beam1ParticleMass =  CLHEP::proton_mass_c2;
    // m_beam2ParticleMass =  CLHEP::proton_mass_c2;
 
    return StatusCode::SUCCESS;
  }

initializeGenEvent()

StatusCode Simulation::GenEventBeamEffectBooster::initializeGenEvent ( CLHEP::HepLorentzRotation & transform, const EventContext & ctx ) const

private

calculate the transformations that we want to apply to the particles in the current GenEvent

Definition at line 77 of file GenEventBeamEffectBooster.cxx.

  {
    // Reset the transformation
    transform = CLHEP::HepLorentzRotation(); //TODO drop this
 
    // Prepare the random engine
    m_randomEngine->setSeed( name(), ctx );
    CLHEP::HepRandomEngine* randomEngine(m_randomEngine->getEngine(ctx));
 
    // Create beam 1 and 2 momenta, including divergence and crossing-angle effects
    const double px1 = m_pbeam1 * CLHEP::RandGaussZiggurat::shoot(randomEngine, m_xing_x_b2, m_sigma_px_b2);
    const double py1 = m_pbeam1 * CLHEP::RandGaussZiggurat::shoot(randomEngine, m_xing_y_b2, m_sigma_py_b2);
    const double pz1 = CLHEP::RandGaussZiggurat::shoot(randomEngine, sqrt(m_pbeam1*m_pbeam1 - px1*px1 - py1*py1), m_dE);
    const double e1 = sqrt(px1*px1 + py1*py1 + pz1*pz1 + m_beam1ParticleMass*m_beam1ParticleMass);
    CLHEP::HepLorentzVector pp1(px1, py1, pz1, e1);
 
    const double px2 = -m_pbeam2 * CLHEP::RandGaussZiggurat::shoot(randomEngine, m_xing_x_b1, m_sigma_px_b1); // crossing angle & divergence
    const double py2 = -m_pbeam2 * CLHEP::RandGaussZiggurat::shoot(randomEngine, m_xing_y_b1, m_sigma_py_b1);
    const double pz2 = CLHEP::RandGaussZiggurat::shoot(randomEngine, -sqrt(m_pbeam2*m_pbeam2 - px2*px2 - py2*py2), m_dE); // longitudinal component in + direction energy smeared
    const double e2 = sqrt(px2*px2 + py2*py2 + pz2*pz2 + m_beam2ParticleMass*m_beam2ParticleMass);
    CLHEP::HepLorentzVector pp2(px2, py2, pz2, e2);
 
    // Now set-up rotation-boost matrix
    const CLHEP::HepLorentzVector psum = pp1 + pp2;
    const CLHEP::HepLorentzVector& dir = pp1;
    // Boost psum back on the direction of dir, adapted from bstback & fromCMframe PYTHIA8, credit to T.Sjostrand
    const double betaX = -psum.x() / psum.t();
    const double betaY = -psum.y() / psum.t();
    const double betaZ = -psum.z() / psum.t();
    const double beta2 = betaX*betaX + betaY*betaY + betaZ*betaZ;
    const double gamma = 1. / sqrt(1. - beta2);
    const double prod1 = betaX * dir.x() + betaY * dir.y() + betaZ * dir.z();
    const double prod2 = gamma * (gamma * prod1 / (1. + gamma) + dir.t());
    // Get the angle of rotation
    const CLHEP::HepLorentzVector back(dir.x() + prod2 * betaX,
                                       dir.y() + prod2 * betaY,
                                       dir.z() + prod2 * betaZ,
                                       gamma * (dir.t() + prod1));
    const double thback = back.theta();
    const double phback = back.phi();
    // Setting up two rotation matrices, via 3x3 rep. rather than even more messy EulerAngles
    const double sph = sin(phback), cph = cos(phback), sth = sin(thback), cth = cos(thback);
    const CLHEP::HepRotation rot1(CLHEP::HepRep3x3(cph, sph, 0.0, -sph, cph, 0.0, 0.0, 0.0, 1.0));
    const CLHEP::HepRotation rot2(CLHEP::HepRep3x3(cth*cph, -sph, sth*cph, cth*sph, cph, sth*sph, -sth, 0.0, cth));
    const CLHEP::HepBoost bst(psum.px()/psum.e(), psum.py()/psum.e(), psum.pz()/psum.e());
    // Combine the two rotations and the boost; matrix multiplication order matters
    const CLHEP::HepRotation rot = rot2*rot1;
    if(m_applyBoost && m_applyDivergence) {
      transform.set(rot,bst);
    }
    else {
      if(m_applyBoost) {
        transform.set(bst);
      }
      if(m_applyDivergence) {
        transform.set(rot);
      }
    }
    return StatusCode::SUCCESS;
  }

manipulate()

StatusCode Simulation::GenEventBeamEffectBooster::manipulate ( HepMC::GenEvent & ge, const EventContext & ctx ) const

finaloverride

modifies the given GenEvent

modifies (displaces) the given GenEvent

Definition at line 139 of file GenEventBeamEffectBooster.cxx.

  {
    // Obtain the transformation
    CLHEP::HepLorentzRotation transform = CLHEP::HepLorentzRotation();
    ATH_CHECK( initializeGenEvent(transform, ctx) );
 
    for( auto particleIter: ge) {
      this->boostParticle(particleIter, transform);
    }
    return StatusCode::SUCCESS;
  }

Member Data Documentation

ATLAS_THREAD_SAFE

ATHRNG::RNGWrapper* m_randomEngine Simulation::GenEventBeamEffectBooster::ATLAS_THREAD_SAFE {}

private

Slot-local RNG.

Definition at line 60 of file GenEventBeamEffectBooster.h.

{};  

m_applyBoost

Gaudi::Property<bool> Simulation::GenEventBeamEffectBooster::m_applyBoost {this, "ApplyBoost", true}

private

Definition at line 62 of file GenEventBeamEffectBooster.h.

{this, "ApplyBoost", true};

m_applyDivergence

Gaudi::Property<bool> Simulation::GenEventBeamEffectBooster::m_applyDivergence {this, "ApplyDivergence", true}

private

Definition at line 63 of file GenEventBeamEffectBooster.h.

{this, "ApplyDivergence", true};

m_beam1ParticleMass

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_beam1ParticleMass {this, "Beam1ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 1"}

private

Todo

Get from a service

Definition at line 78 of file GenEventBeamEffectBooster.h.

{this, "Beam1ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 1"};

m_beam2ParticleMass

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_beam2ParticleMass {this, "Beam2ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 2"}

private

Definition at line 79 of file GenEventBeamEffectBooster.h.

{this, "Beam2ParticleMass", CLHEP::proton_mass_c2, "Mass of particle used in beam 2"};

m_dE

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_dE {this, "deltaEOverE", 1.1E-4, "Delta_E/E theoretical value"}

private

Definition at line 75 of file GenEventBeamEffectBooster.h.

{this,  "deltaEOverE", 1.1E-4, "Delta_E/E theoretical value"}; // Delta_E/E theoretical value

m_pbeam1

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_pbeam1 {this, "pbeam1", 3500.0E3, "Beam 1 Momentum / MeV"}

private

Definition at line 76 of file GenEventBeamEffectBooster.h.

{this, "pbeam1",        3500.0E3,    "Beam 1 Momentum / MeV"}; 

m_pbeam2

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_pbeam2 {this, "pbeam2", 3500.0E3, "Beam 2 Momentum / MeV"}

private

Todo

Get from a service

Definition at line 77 of file GenEventBeamEffectBooster.h.

{this, "pbeam2",        3500.0E3,    "Beam 2 Momentum / MeV"}; 

m_randomEngineName

Gaudi::Property<std::string> Simulation::GenEventBeamEffectBooster::m_randomEngineName {this, "RandomStream", "BEAM"}

private

Name of the random number stream.

Definition at line 61 of file GenEventBeamEffectBooster.h.

{this, "RandomStream", "BEAM"};         

m_rndGenSvc

ServiceHandle<IAthRNGSvc> Simulation::GenEventBeamEffectBooster::m_rndGenSvc {this, "RandomSvc", "AthRNGSvc"}

private

Definition at line 59 of file GenEventBeamEffectBooster.h.

{this, "RandomSvc", "AthRNGSvc"};

m_sigma_px_b1

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_sigma_px_b1 {this, "Sigma_px_b1", 20.e-6, "angular divergence in x of beam 1 [rad]"}

private

Definition at line 66 of file GenEventBeamEffectBooster.h.

{this, "Sigma_px_b1", 20.e-6, "angular divergence in x of beam 1 [rad]"};

m_sigma_px_b2

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_sigma_px_b2 {this, "Sigma_px_b2", 21.e-6, "angular divergence in x of beam 2 [rad]"}

private

Definition at line 67 of file GenEventBeamEffectBooster.h.

{this, "Sigma_px_b2", 21.e-6, "angular divergence in x of beam 2 [rad]"};

m_sigma_py_b1

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_sigma_py_b1 {this, "Sigma_py_b1", 22.e-6, "angular divergence in y of beam 1 [rad]"}

private

Definition at line 68 of file GenEventBeamEffectBooster.h.

{this, "Sigma_py_b1", 22.e-6, "angular divergence in y of beam 1 [rad]"};

m_sigma_py_b2

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_sigma_py_b2 {this, "Sigma_py_b2", 23.e-6, "angular divergence in y of beam 2 [rad]"}

private

Definition at line 69 of file GenEventBeamEffectBooster.h.

{this, "Sigma_py_b2", 23.e-6, "angular divergence in y of beam 2 [rad]"};

m_xing_x_b1

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_xing_x_b1 {this, "HalfXing_x_b1", 19.e-6, "half-crossing in x for beam 1 at IP1, i.e. angle between beam 1 and z-axis"}

private

Definition at line 71 of file GenEventBeamEffectBooster.h.

{this, "HalfXing_x_b1", 19.e-6, "half-crossing in x for beam 1 at IP1, i.e. angle between beam 1 and z-axis"};

m_xing_x_b2

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_xing_x_b2 {this, "HalfXing_x_b2", 1.e-6, "half-crossing in x for beam 2 at IP1, i.e. angle between beam 2 and z-axis"}

private

Definition at line 72 of file GenEventBeamEffectBooster.h.

{this, "HalfXing_x_b2", 1.e-6, "half-crossing in x for beam 2 at IP1, i.e. angle between beam 2 and z-axis"};

m_xing_y_b1

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_xing_y_b1 {this, "HalfXing_y_b1", 150.e-6, "half-crossing in y for beam 1 at IP1, i.e. angle between beam 1 and z-axis"}

private

Definition at line 73 of file GenEventBeamEffectBooster.h.

{this, "HalfXing_y_b1", 150.e-6, "half-crossing in y for beam 1 at IP1, i.e. angle between beam 1 and z-axis"};

m_xing_y_b2

Gaudi::Property<double> Simulation::GenEventBeamEffectBooster::m_xing_y_b2 {this, "HalfXing_y_b2", -152.e-6, "half-crossing in y for beam 2 at IP1, i.e. angle between beam 2 and z-axis"}

private

Definition at line 74 of file GenEventBeamEffectBooster.h.

{this, "HalfXing_y_b2", -152.e-6, "half-crossing in y for beam 2 at IP1, i.e. angle between beam 2 and z-axis"};

---

The documentation for this class was generated from the following files:

• GenEventBeamEffectBooster.h
• GenEventBeamEffectBooster.cxx