#include <CrabKissingVertexPositioner.h>

Inheritance diagram for Simulation::CrabKissingVertexPositioner:

Collaboration diagram for Simulation::CrabKissingVertexPositioner:

Public Member Functions
	CrabKissingVertexPositioner (const std::string &t, const std::string &n, const IInterface *p)
	Constructor with parameters. More...

virtual	~CrabKissingVertexPositioner ()=default
	Destructor. More...

StatusCode	initialize () override final
	Athena algtool's Hooks. More...

StatusCode	finalize () override final
	Athena algtool's Hooks. More...

CLHEP::HepLorentzVector *	generate (const EventContext &ctx) const override final
	computes the vertex displacement More...

Private Types
enum	BunchShape { GAUSS, FLAT, NSHAPES }

Private Member Functions
double	heaviside (double val) const

double	getDisplacement (double bunchSize, double angle1, double angle2, CLHEP::HepRandomEngine *rng) const

double	beamspotFunction (double displacement, double angle1, double angle2) const

void	BunchShapeHandler (Gaudi::Details::PropertyBase &)

Private Attributes
SG::ReadCondHandleKey< InDet::BeamSpotData >	m_beamSpotKey { this, "BeamSpotKey", "BeamSpotData", "SG key for beam spot" }

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

ATHRNG::RNGWrapper *m_randomEngine	ATLAS_THREAD_SAFE {}
	Slot-local RNG. More...

Gaudi::Property< std::string >	m_randomEngineName {this, "RandomStream", "VERTEX", "Name of the random number stream"}

Gaudi::Property< std::string >	m_bunchShapeProp {this, "BunchShape", "GAUSS", "GAUSS or FLAT"}

BunchShape	m_bunchShape {BunchShape::GAUSS}

Gaudi::Property< double >	m_bunchLength {this, "BunchLength", 75., "75.0 mm"}
	Parameter in the Z distribution of the beamspot. More...

Gaudi::Property< double >	m_betaStar {this, "BetaStar", 150., "beta* in the parallel (kissing) plane, we assume betax=betay, units: mm"}
	parameters according to S.Fartoukh Phys.Rev.ST Accel.Beams 17 (2014) no.11, 111001 -------------------------— More...

Gaudi::Property< double >	m_epsilon {this, "Epsilon", 2.5e-3, "Normalized emittance, unit: mm"}

Gaudi::Property< double >	m_alphaPar {this, "AlfasParallel", 0., "Kissing angle (Radians)"}

Gaudi::Property< double >	m_alphaX {this, "AlfaX", 295e-6}

Gaudi::Property< double >	m_thetaX {this, "ThetaX", 295e-6}

Detailed Description

This AthenaTool computes geometrical shifts for the initial GenEvent vertices.

based on function from S.Fartoukh Phys.Rev.ST Accel.Beams 17 (2014) no.11, 111001

Author: John.Chapman -at- cern.ch, Elmar.Ritsch -at- cern.ch, Daniele.Ruini -at- poltechnique.edu

Definition at line 43 of file CrabKissingVertexPositioner.h.

Member Enumeration Documentation

◆ BunchShape

enum Simulation::CrabKissingVertexPositioner::BunchShape

private

Enumerator
GAUSS
FLAT
NSHAPES

Definition at line 73 of file CrabKissingVertexPositioner.h.

73 {GAUSS,FLAT,NSHAPES};

Constructor & Destructor Documentation

◆ CrabKissingVertexPositioner()

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

Constructor with parameters.

Constructor.

Definition at line 25 of file CrabKissingVertexPositioner.cxx.

     : base_class(t,n,p)
   {
     m_bunchShapeProp.declareUpdateHandler(&CrabKissingVertexPositioner::BunchShapeHandler, this);
   }

◆ ~CrabKissingVertexPositioner()

virtual Simulation::CrabKissingVertexPositioner::~CrabKissingVertexPositioner ( )

virtualdefault

Destructor.

Member Function Documentation

◆ beamspotFunction()

double Simulation::CrabKissingVertexPositioner::beamspotFunction	(	double	displacement,
		double	angle1,
		double	angle2
	)		const

private

Definition at line 78 of file CrabKissingVertexPositioner.cxx.

   {
     if ( angle1<1e-10 ) angle1 = 1e-10; // to avoid divide_by_zero errors
     double temp(1.0-std::fabs(displacement)/m_bunchLength);
     return 1.0/M_2_SQRTPI * std::erf(angle1*temp)/angle1 *
            std::exp( -pow(angle2*displacement/m_bunchLength, 2) ) *
            heaviside(temp);
   }

◆ BunchShapeHandler()

void Simulation::CrabKissingVertexPositioner::BunchShapeHandler ( Gaudi::Details::PropertyBase & )

private

Definition at line 33 of file CrabKissingVertexPositioner.cxx.

   {
     if(m_bunchShapeProp.value() == "GAUSS") m_bunchShape = BunchShape::GAUSS;
     else if(m_bunchShapeProp.value() == "FLAT") m_bunchShape = BunchShape::FLAT;
     else m_bunchShape=BunchShape::NSHAPES;
   }

◆ finalize()

StatusCode Simulation::CrabKissingVertexPositioner::finalize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 69 of file CrabKissingVertexPositioner.cxx.

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

◆ generate()

CLHEP::HepLorentzVector * Simulation::CrabKissingVertexPositioner::generate ( const EventContext & ctx ) const

finaloverride

computes the vertex displacement

Definition at line 103 of file CrabKissingVertexPositioner.cxx.

   {
     // Prepare the random engine
     m_randomEngine->setSeed( name(), ctx );
     CLHEP::HepRandomEngine* randomEngine(m_randomEngine->getEngine(ctx));
     SG::ReadCondHandle<InDet::BeamSpotData> beamSpotHandle { m_beamSpotKey, ctx };
     // See jira issue ATLASSIM-497 for an explanation of why calling
     // shoot outside the CLHEP::HepLorentzVector constructor is
     // necessary/preferable.
     double vertexX = CLHEP::RandGaussZiggurat::shoot(randomEngine)*beamSpotHandle->beamSigma(0);
     double vertexY = CLHEP::RandGaussZiggurat::shoot(randomEngine)*beamSpotHandle->beamSigma(1);
     double piwinski_phi = std::fabs(m_thetaX - m_alphaX) * m_bunchLength/std::sqrt(m_epsilon * m_betaStar);
     double piwinski_psi = m_alphaPar * m_bunchLength / std::sqrt( m_epsilon * m_betaStar);
     double vertexZ = 0;
     double vertexT = 0;
     // Time should be set in units of distance, the following methods generate c*t
     if ( m_bunchShape == BunchShape::GAUSS) {
       double zWidth    = m_bunchLength / std::sqrt(2*(1+pow(piwinski_phi,2)));
       double timeWidth = m_bunchLength / std::sqrt(2*(1+pow(piwinski_psi,2)));
       vertexZ = CLHEP::RandGaussZiggurat::shoot(randomEngine, 0., zWidth);
       vertexT = CLHEP::RandGaussZiggurat::shoot(randomEngine, 0., timeWidth);
     }
     else if ( m_bunchShape == BunchShape::FLAT ) {
       vertexZ = getDisplacement(m_bunchLength, piwinski_psi, piwinski_phi, randomEngine);
       vertexT = getDisplacement(m_bunchLength, piwinski_phi, piwinski_psi, randomEngine);
     }
     else {
       ATH_MSG_WARNING("Invalid BunchShape ("<<m_bunchShapeProp.value()<<"). Vertex smearing disabled");
       return new CLHEP::HepLorentzVector(0.,0.,0.,0.);
     }
     ATH_MSG_VERBOSE("m_bunchLength = " << m_bunchLength <<
                     ", Zvertex = " << vertexZ << ", Tvertex = " << vertexT);
  
     // calculate the vertexSmearing
     CLHEP::HepLorentzVector *vertexSmearing =
       new CLHEP::HepLorentzVector( vertexX, vertexY, vertexZ, 0. );
  
     // (1) code from: Simulation/G4Atlas/G4AtlasUtilities/VertexPositioner.cxx
     const double tx = tan( beamSpotHandle->beamTilt(1) );
     const double ty = tan( beamSpotHandle->beamTilt(0) );
  
     const double sqrt_abc = std::sqrt(1. + tx*tx + ty*ty);
     const double sqrt_fgh = std::sqrt(1. + ty*ty);
  
     const double a = ty/sqrt_abc;
     const double b = tx/sqrt_abc;
     const double c = 1./sqrt_abc;
  
     HepGeom::Point3D<double> from1(0,0,1);
     HepGeom::Point3D<double> to1(a,b,c);
  
     const double f = 1./sqrt_fgh;
     const double g = 0.;
     const double h = -(ty)/sqrt_fgh;
  
     HepGeom::Point3D<double> from2(1,0,0);
     HepGeom::Point3D<double> to2(f,g,h);
  
     // first rotation, then translation
     HepGeom::Transform3D transform(
         HepGeom::Rotate3D(from1, from2, to1, to2).getRotation(),
         CLHEP::Hep3Vector( beamSpotHandle->beamPos().x(),
                            beamSpotHandle->beamPos().y(),
                            beamSpotHandle->beamPos().z() )
         );
  
     ATH_MSG_VERBOSE("BeamSpotSvc reported beam position as " << beamSpotHandle->beamPos());
     ATH_MSG_VERBOSE("Width is (" << beamSpotHandle->beamSigma(0) << ", " <<
                     beamSpotHandle->beamSigma(1) << ", " << m_bunchLength << ")");
     ATH_MSG_VERBOSE("Tilts are " << beamSpotHandle->beamTilt(0) << " and " <<
                     beamSpotHandle->beamTilt(1));
     ATH_MSG_VERBOSE("Vertex Position before transform: " << *vertexSmearing);
  
     // update with the tilt
     *vertexSmearing = transform * HepGeom::Point3D<double>(*vertexSmearing);
     vertexSmearing->setT(vertexT);
  
     // and return it
     return vertexSmearing;
   }

◆ getDisplacement()

double Simulation::CrabKissingVertexPositioner::getDisplacement	(	double	bunchSize,
		double	angle1,
		double	angle2,
		CLHEP::HepRandomEngine *	rng
	)		const

private

Definition at line 87 of file CrabKissingVertexPositioner.cxx.

   {
     size_t ntries(0);
     double yval(CLHEP::RandFlat::shoot(randomEngine, 0.0, 1.0));
     double displ(CLHEP::RandFlat::shoot(randomEngine, -bunchSize, bunchSize));
     while (this->beamspotFunction(displ, angle1, angle2)<yval) {
       if(ntries>1000000) return 0.0; //just so we don't sit in this loop forever
       yval = CLHEP::RandFlat::shoot(randomEngine, 0.0, 1.0);
       displ = CLHEP::RandFlat::shoot(randomEngine, -bunchSize, bunchSize);
       ++ntries;
     }
     return displ;
   }

◆ heaviside()

double Simulation::CrabKissingVertexPositioner::heaviside ( double val ) const

inlineprivate

Definition at line 62 of file CrabKissingVertexPositioner.h.

62 {return (val >= 0.0) ? 1.0 : 0.0;};

◆ initialize()

StatusCode Simulation::CrabKissingVertexPositioner::initialize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 41 of file CrabKissingVertexPositioner.cxx.

   {
     ATH_MSG_VERBOSE("Initializing ...");
  
     // prepare the RandonNumber generation
     ATH_CHECK(m_rndGenSvc.retrieve());
     ATH_CHECK(m_beamSpotKey.initialize());
  
     m_randomEngine = m_rndGenSvc->getEngine(this, m_randomEngineName);
     if (!m_randomEngine) {
       ATH_MSG_ERROR("Could not get random number engine from RandomNumberService. Abort.");
       return StatusCode::FAILURE;
     }
  
     ATH_MSG_DEBUG("BunchShape = " << m_bunchShapeProp.value());
     ATH_MSG_DEBUG("BunchLength = " << m_bunchLength);
     ATH_MSG_DEBUG("Epsilon (normalized emittance) = " << m_epsilon);
     ATH_MSG_DEBUG("BetaStar = " << m_betaStar);
     ATH_MSG_DEBUG("AlfaParallel (kissing angle) = " << m_alphaPar);
     ATH_MSG_DEBUG("AlfaX (crabbing angle) = " << m_alphaX);
     ATH_MSG_DEBUG("ThetaX (half crossing angle) = " << m_thetaX);
  
     // everything set up properly
     return StatusCode::SUCCESS;
   }

Member Data Documentation

◆ ATLAS_THREAD_SAFE

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

private

Slot-local RNG.

Definition at line 69 of file CrabKissingVertexPositioner.h.

◆ m_alphaPar

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_alphaPar {this, "AlfasParallel", 0., "Kissing angle (Radians)"}

private

Definition at line 79 of file CrabKissingVertexPositioner.h.

◆ m_alphaX

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_alphaX {this, "AlfaX", 295e-6}

private

Definition at line 80 of file CrabKissingVertexPositioner.h.

◆ m_beamSpotKey

SG::ReadCondHandleKey<InDet::BeamSpotData> Simulation::CrabKissingVertexPositioner::m_beamSpotKey { this, "BeamSpotKey", "BeamSpotData", "SG key for beam spot" }

private

Definition at line 67 of file CrabKissingVertexPositioner.h.

◆ m_betaStar

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_betaStar {this, "BetaStar", 150., "beta* in the parallel (kissing) plane, we assume betax=betay, units: mm"}

private

parameters according to S.Fartoukh Phys.Rev.ST Accel.Beams 17 (2014) no.11, 111001 -------------------------—

Definition at line 77 of file CrabKissingVertexPositioner.h.

◆ m_bunchLength

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_bunchLength {this, "BunchLength", 75., "75.0 mm"}

private

Parameter in the Z distribution of the beamspot.

Definition at line 75 of file CrabKissingVertexPositioner.h.

◆ m_bunchShape

BunchShape Simulation::CrabKissingVertexPositioner::m_bunchShape {BunchShape::GAUSS}

private

Definition at line 74 of file CrabKissingVertexPositioner.h.

◆ m_bunchShapeProp

Gaudi::Property<std::string> Simulation::CrabKissingVertexPositioner::m_bunchShapeProp {this, "BunchShape", "GAUSS", "GAUSS or FLAT"}

private

Definition at line 71 of file CrabKissingVertexPositioner.h.

◆ m_epsilon

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_epsilon {this, "Epsilon", 2.5e-3, "Normalized emittance, unit: mm"}

private

Definition at line 78 of file CrabKissingVertexPositioner.h.

◆ m_randomEngineName

Gaudi::Property<std::string> Simulation::CrabKissingVertexPositioner::m_randomEngineName {this, "RandomStream", "VERTEX", "Name of the random number stream"}

private

Definition at line 70 of file CrabKissingVertexPositioner.h.

◆ m_rndGenSvc

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

private

Definition at line 68 of file CrabKissingVertexPositioner.h.

◆ m_thetaX

Gaudi::Property<double> Simulation::CrabKissingVertexPositioner::m_thetaX {this, "ThetaX", 295e-6}

private

Definition at line 81 of file CrabKissingVertexPositioner.h.

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

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ BunchShape

Constructor & Destructor Documentation

◆ CrabKissingVertexPositioner()

◆ ~CrabKissingVertexPositioner()

Member Function Documentation

◆ beamspotFunction()

◆ BunchShapeHandler()

◆ finalize()

◆ generate()

◆ getDisplacement()

◆ heaviside()

◆ initialize()

Member Data Documentation

◆ ATLAS_THREAD_SAFE

◆ m_alphaPar

◆ m_alphaX

◆ m_beamSpotKey

◆ m_betaStar

◆ m_bunchLength

◆ m_bunchShape

◆ m_bunchShapeProp

◆ m_epsilon

◆ m_randomEngineName

◆ m_rndGenSvc

◆ m_thetaX