PaAlgo Class Reference

Miscellaneous functions. More...

#include <PaAlgo.h>

Static Public Member Functions
static bool	GetTargetLocation (int run, double &xU, double &yU, double &zU_1, double &zU_2, double &xD, double &yD, double &zD_1, double &zD_2, double &R, double &yCUT)
	Gives the target location in space: shift and tilting. Returns false if no information for the given year.
static bool	CrossCells (PaTPar par, int run, double R_U=-9999, double yCUT_U=-9999)
	The requirement that the muon beam trajectory crosses entirely two target cells. It is used in order to equalize fluxes through both cells.
static bool	InTarget (PaTPar par, char Cell, int run, double R_U=-9999, double yCUT_U=-9999)
	The check for the primary vertex to be in one of the target cells.
static double	GetBeamPol (float mom, int year)
	Returns the average muon beam polarization.
static void	GetDepolarizationFactor (double q2, double xBj, double y, double R, double dR, double &D, double &dD, bool do_err=true)
	Returns the depolarization factor.
static void	GetDepolarizationFactor (double q2, double xBj, double y, double &D, double &dD, bool do_err=true)
	Returns the depolarization factor.
static void	GetDilutionFactor (float xBj, float y, char Cell, int run, int flag, float &f, float &df)
	Returns the dilution factor and its error.
static void	GetR (float q2, float xBj, float &R, float &dR, bool do_err=true)
	Returns the R1990 value.
static void	GetRadiativeWeight (float xBj, float y, int flag, float &rc)
	Returns the radiative correction weight (DEPRECATED).
static float	GetRadiativeWeight (float xBj, float y, int flag)
	Returns the radiative correction weight.
static bool	DoMW1ID (const PaTrack &t, int nma1=0, int nma2=0)
	return "true" is track "t" is identified in MW1
static int	GetMW1ScatMuon (const PaEvent &e)
	returns the index of the candidate scattered muon identified in MW1
static double	Q2 (double pmu0, double pmu, double Cos, double mmu=0.105658357)
	Q² via momenta and Cos.
static double	Q2 (const TVector3 &pmu0, const TVector3 &pmu, double mmu=0.105658357)
	Q² via 3-vectors.
static double	Q2 (const TLorentzVector &pmu0, const TLorentzVector &pmu)
	Q² via Lorentz vectors.
static double	xbj (double pmu0, double pmu, double Cos, double m_P=0.93827231, double mmu=0.105658357)
	x_Bjorken via momenta and Cos
static double	xbj (const TVector3 &pmu0, const TVector3 &pmu, double m_P=0.93827231, double mmu=0.105658357)
	x_Bjorken via 3-vectors
static double	xbj (const TLorentzVector &pmu0, const TLorentzVector &pmu, double m_P=0.93827231)
	x_Bjorken via Lorentz vectors
static double	W2 (double pmu0, double pmu, double Cos, double m_P=0.93827231, double mmu=0.105658357)
	W² via momenta and Cos.
static double	W2 (const TVector3 &pmu0, const TVector3 &pmu, double m_P=0.93827231, double mmu=0.105658357)
	W² via 3-vectors.
static double	W2 (const TLorentzVector &pmu0, const TLorentzVector &pmu, double m_P=0.93827231)
	W² via Lorentz vectors.
static void	Boost (const TVector3 &v0, double m0, const TVector3 &v1, double m1, TVector3 &v10)
	boost via 3-vectors
static void	Boost (const TLorentzVector &v0, const TLorentzVector &v1, TVector3 &v10)
	boost via Lorentz vectors
static void	Boost (const TLorentzVector &v0, const TLorentzVector &v1, TLorentzVector &v10)
	boost via Lorentz vectors
static double	Xf (const TVector3 &pmu0, const TVector3 &pmu, const TVector3 &plh, double mh=0.13957018, double m_P=0.93827231, double mmu=0.105658357)
	x_F via 3-vectors
static double	Xf (const TLorentzVector &pmu0, const TLorentzVector &pmu, const TLorentzVector &plh, double m_P=0.93827231)
	x_F via Lorentz vectors
static double	E (double m, const TVector3 &p)
	Energy via mass and 3-vector.
static double	M (double e, const TVector3 &p)
	Mass via energy and 3-vector.
static bool	RKutta (double SU, double VO, double &Path)
	Trajectory propagation in magnetic field by Runge-Kutta method with Jacobian calculations.
static void	RedefMass (TLorentzVector &lv, double mass)
	Change the energy part of the Lorentz vector "lv" to corresponds exactly to mass "mass".

Detailed Description

Miscellaneous functions.

Collection of independent,"self-contained" algorithms and useful physics-related functions.

Member Function Documentation

void PaAlgo::Boost	(	const TLorentzVector &	v0,
		const TLorentzVector &	v1,
		TLorentzVector &	v10
	)			`[inline, static]`

boost via Lorentz vectors

The Lorentz transformation of the particle v1 to the rest frame of the particle v0.

Parameters:

	v0	the four-vector of particle 0 in laboratory frame
	v1	the four-vector of particle 1 in laboratory frame
	v10	the four-vector of the particle 1 in the rest frame of 0

Author:: Alexandre.Korzenev@cern.ch

References Boost().

void PaAlgo::Boost	(	const TLorentzVector &	v0,
		const TLorentzVector &	v1,
		TVector3 &	v10
	)			`[inline, static]`

boost via Lorentz vectors

The Lorentz transformation of the particle v1 to the rest frame of the particle v0.

Parameters:

	v0	the four-vector of particle 0 in laboratory frame
	v1	the four-vector of particle 1 in laboratory frame
	v10	the momentum vector of the particle 1 in the rest frame of 0

Author:: Alexandre.Korzenev@cern.ch

References Boost().

void PaAlgo::Boost	(	const TVector3 &	v0,
		double	m0,
		const TVector3 &	v1,
		double	m1,
		TVector3 &	v10
	)			`[inline, static]`

boost via 3-vectors

The Lorentz transformation of the particle {v1, m1} to the rest frame of the particle {v0, m0}.

Parameters:

	v0	the momentum vector of particle 0 in laboratory frame
	m0	the mass of the particle 0
	v1	the momentum vector of particle 1 in laboratory frame
	m1	the mass of the particle 1
	v10	the momentum vector of the particle 1 in the rest frame of 0

Author:: Alexandre.Korzenev@cern.ch

References E().

Referenced by Boost().

bool PaAlgo::CrossCells	(	PaTPar	par,
		int	run,
		double	R_U = `-9999`,
		double	yCUT_U = `-9999`
	)			`[static]`

The requirement that the muon beam trajectory crosses entirely two target cells. It is used in order to equalize fluxes through both cells.

Parameters:

	par	the beam track parameters in the primary vertex
	run	the run number ("-2" = 2 cell MC, "-3" = 3 cell MC LiD, "-4" = 3 cell MC NH3)
	R_U	the user defined radial cut (R<1.4cm)
	yCUT_U	the user defined vertical cut (y<1cm)

Author:: Alexandre.Korzenev@cern.ch

References PaTPar::Extrapolate(), and GetTargetLocation().

bool PaAlgo::DoMW1ID	(	const PaTrack &	t,
		int *	nma1 = `0`,
		int *	nma2 = `0`
	)			`[static]`

return "true" is track "t" is identified in MW1

The number of clusters associated to the track before and after the absorber is stored in nma1 and nma2 respectively if they are not null pointers.

Author:: Andrea Ferrero <aferrero@to.infn.it>

References PaTrack::NHitsFoundInDetect().

Referenced by GetMW1ScatMuon().

double PaAlgo::GetBeamPol	(	float	mom,
		int	year
	)			`[static]`

Returns the average muon beam polarization.

Parameters:

	mom	the momentum of the beam muon track
	year	the year of data taking (2002, 2003 or 2004).

void PaAlgo::GetDepolarizationFactor	(	double	q2,
		double	xBj,
		double	y,
		double &	D,
		double &	dD,
		bool	do_err = `true`
	)			`[static]`

Returns the depolarization factor.

Parameters:

	q2	squared invariant mass of the virtual photon
	xBj	Bjorken x
	y	energy fraction carried by the virtual photon
	D	resulting depolarization factor
	dD	calculated error on D (if do_err==true)
	do_err	flag which controls whether the error calculation should be done (defaults to 'yes')

This function is not available when Phast is compiled with NO_FORTRAN=1

This function is a convenience wrapper for the first variant which takes the value of R+-dR from PaAlgo::GetR().

Author:: Roland.Kuhn@cern.ch

References GetDepolarizationFactor(), and GetR().

void PaAlgo::GetDepolarizationFactor	(	double	q2,
		double	xBj,
		double	y,
		double	R,
		double	dR,
		double &	D,
		double &	dD,
		bool	do_err = `true`
	)			`[static]`

Returns the depolarization factor.

Parameters:

	q2	squared invariant mass of the virtual photon
	xBj	Bjorken x
	y	energy fraction carried by the virtual photon
	R	R value (e.g. from r1990.F)
	dR	error on R
	D	resulting depolarization factor
	dD	calculated error on D (if do_err==true)
	do_err	flag which controls whether the error calculation should be done (defaults to 'yes')

The code in this function is taken from the A1 analysis code (thanks to A. Korzenev). This function does not invoke any external FORTRAN code, which means that if you have your own source for the R values you can use it even when compiling Phast with NO_FORTRAN=1.

Author:: Roland.Kuhn@cern.ch

References M().

Referenced by GetDepolarizationFactor().

void PaAlgo::GetDilutionFactor	(	float	xBj,
		float	y,
		char	Cell,
		int	run,
		int	flag,
		float &	f,
		float &	df
	)			`[static]`

Returns the dilution factor and its error.

Parameters:

	xBj	Bjorken x
	y	energy fraction carried by the virtual photon
	Cell	target cell (U=upstream, C=central, D=downstream)
	run	run number.
	flag	processing flag (1=inclusive, 2=hadron_tagged)
	f	dilution factor
	df	error for the dilution factor

This function is not available when Phast is compiled with NO_FORTRAN=1

This function calls the FORTRAN routine dfdeut from ./fortran/dilut_main.F to get the dilution factor for the various regions of the target.

Beware: The FORTRAN routine gives only float values!

Author:: Alexandre.Korzenev@cern.ch

int PaAlgo::GetMW1ScatMuon ( const PaEvent & e ) [static]

returns the index of the candidate scattered muon identified in MW1

Returns the best scattered muon candidate as identified by MW1. The track is selected among those coming out of the "best primary vertex", as given by iBestPrimaryVertex() function. The identification is performed only in the case of calorimetric trigger events.

Author:: Andrea Ferrero <aferrero@to.infn.it>

References DoMW1ID(), PaEvent::iBestPrimaryVertex(), PaVertex::iOutParticle(), PaParticle::iTrack(), PaVertex::NOutParticles(), PaEvent::TrigMask(), PaEvent::vParticle(), PaEvent::vTrack(), and PaEvent::vVertex().

void PaAlgo::GetR	(	float	q2,
		float	xBj,
		float &	R,
		float &	dR,
		bool	do_err = `true`
	)			`[static]`

Returns the R1990 value.

Parameters:

	q2	squared invariant mass of the virtual photon
	xBj	Bjorken x
	R	result (float!)
	dR	error on R (if do_err==true)
	do_err	flag which controls whether the error calculation should be done (defaults to 'yes')

This function is not available when Phast is compiled with NO_FORTRAN=1

This function calls the FORTRAN routing r1990 from ./fortran/r1990.F to get the R parameterization.

Beware: The FORTRAN routine gives only float values!

Author:: Roland Kuhn <roland.kuhn@cern.ch>

Referenced by GetDepolarizationFactor().

float PaAlgo::GetRadiativeWeight	(	float	xBj,
		float	y,
		int	flag
	)			`[static]`

Returns the radiative correction weight.

Parameters:

	xBj	Bjorken x
	y	energy fraction carried by the virtual photon
	flag	processing flag (1=inclusive(deuter), 2=hadron_tagged(deuter), 11=inclusive(hydrogen), 12=hadron_tagged(hydrogen))

Returns:

The radiative correction factor defined as:

$\eta (x,y) = \frac{\sigma_{1\gamma}}{\sigma_{measured}}$

This factor can be _both_ smaller and larger than 1. For the reference in case of related questions, please look

  =========================================================================
  B. Badelek, D. Bardin, K. Kurek and K. Scholz, Z. Phys. C 66 (1995) 591
  =========================================================================
  and in particular the Eq (4) and Fig 5.

This function is not available when Phast is compiled with NO_FORTRAN=1

This function calls the FORTRAN routine rcinlx or rcinhd from ./fortran/dfdeut.F to get the radiative correction weights from precalculated tables. Tables that are used were generated for dilution factor calculations.

Beware: The FORTRAN routine gives only float values!

Author:: Konrad.Klimaszewski@cern.ch

void PaAlgo::GetRadiativeWeight	(	float	xBj,
		float	y,
		int	flag,
		float &	rc
	)			`[static]`

Returns the radiative correction weight (DEPRECATED).

Deprecated:: This function will exit PHAST with an error message. Please use instead the function: static float PaAlgo::GetRadiativeWeight(float xBj, float y, int flag)

Parameters:

	xBj	Bjorken x
	y	energy fraction carried by the virtual photon
	flag	processing flag (1=inclusive(deuter), 2=hadron_tagged(deuter), 11=inclusive(hydrogen), 12=hadron_tagged(hydrogen))
	rc	resulting radiative correction weight it is defined as: $rc = 1/\eta (x,y) = \frac{\sigma_{measured}}{\sigma_{1\gamma}}$

This function is not available when Phast is compiled with NO_FORTRAN=1

This function calls the FORTRAN routine rcinlx or rcinhd from ./fortran/dfdeut.F to get the radiative correction weights from precalculated tables. Tables that are used were generated for dilution factor calculations.

Beware: The FORTRAN routine gives only float values!

Author:: Konrad.Klimaszewski@cern.ch

bool PaAlgo::GetTargetLocation	(	int	run,
		double &	xU,
		double &	yU,
		double &	zU_1,
		double &	zU_2,
		double &	xD,
		double &	yD,
		double &	zD_1,
		double &	zD_2,
		double &	R,
		double &	yCUT
	)			`[static]`

Gives the target location in space: shift and tilting. Returns false if no information for the given year.

Parameters:

	run	the run number ("-2" = 2 cell MC)
	xU	the shift of the target most upstream part along x
	yU	the shift of the target most upstream part along y
	zU_1	z position of the upstream cell most upstream part
	zU_2	z position of the upstream cell most downstream part
	xD	the shift of the target most downstream part along x
	yD	the shift of the target most downstream part along y
	zD_1	z position of the downstream cell most upstream part
	zD_2	z position of the downstream cell most downstream part
	R	the radial cut
	yCUT	the cut for upper part of the cell

Author:: Alexandre.Korzenev@cern.ch

Referenced by CrossCells(), and InTarget().

bool PaAlgo::InTarget	(	PaTPar	par,
		char	Cell,
		int	run,
		double	R_U = `-9999`,
		double	yCUT_U = `-9999`
	)			`[static]`

The check for the primary vertex to be in one of the target cells.

Parameters:

	par	The beam track parameters in the primary vertex
	Cell	The one of cells (if 'U' - upstream cell, if 'D' - downstream, if 'C' - central)
	run	The run number ("-2" = 2 cell MC, "-3" = 3 cell MC LiD, "-4" = 3 cell MC NH3)
	R_U	the user defined radial cut (R<1.4cm)
	yCUT_U	the user defined vertical cut (y<1cm)

Author:: Alexandre.Korzenev@cern.ch

References GetTargetLocation().

double PaAlgo::Q2	(	const TLorentzVector &	pmu0,
		const TLorentzVector &	pmu
	)			`[inline, static]`

Q² via Lorentz vectors.

Parameters:

	pmu0	the beam Lorentz vector
	pmu	the scattered lepton Lorentz vector

Author:: Alexandre.Korzenev@cern.ch

References Q2().

double PaAlgo::Q2	(	const TVector3 &	pmu0,
		const TVector3 &	pmu,
		double	mmu = `0.105658357`
	)			`[inline, static]`

Q² via 3-vectors.

Parameters:

	pmu0	the beam vector
	pmu	the scattered lepton vector
	mmu	the mass of the lepton (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E().

double PaAlgo::Q2	(	double	pmu0,
		double	pmu,
		double	Cos,
		double	mmu = `0.105658357`
	)			`[inline, static]`

Q² via momenta and Cos.

Parameters:

	pmu0	the absolute value of the beam momentum
	pmu	the absolute value of the scattered lepton momentum
	Cos	the cos of angle between beam and scattered lepton
	mmu	the mass of the lepton (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E().

Referenced by Q2(), W2(), and xbj().

bool PaAlgo::RKutta	(	double *	SU,
		double *	VO,
		double &	Path
	)			`[static]`

Trajectory propagation in magnetic field by Runge-Kutta method with Jacobian calculations.

//------------------------------------------------------------------------------------//
// Runge-Kutta method for tracking a particles through a magnetic field.              //
// Uses Nystroem algorithm (See Handbook Net. Bur. of Standards, procedure 25.5.20    //
//                                                                                    //
// Input parameteres:                                                                 //
//    SU     - plane parameters                                                       //
//    SU [0] - direction cosines normal to surface Ex                                 //
//    SU [1] -          -------                    Ey                                 //
//    SU [2] -          -------                    Ez, Ex*Ex+Ey*Ey+Ez*Ez=1            //
//    SU [3] - distance to surface from (0,0,0) > 0 cm                                //
//    VO     - initial parameters (coordinates(cm), direction cosines,                //
//             charge/momentum (Gev-1) and derivatives this parameters                //
//                                                             Ax*Ax+Ay*Ay+Az*Az=1    //
//      X        Y        Z        Ax       Ay       Az       q/P                     //
//    VO[ 0]   VO[ 1]   VO[ 2]   VO[ 3]   VO[ 4]   VO[ 5]   VO[ 6]                    //
//    dX/dp    dY/dp    dZ/dp    dAx/dp   dAy/dp   dAz/dp   d(q/P)/dp*VO[6]           //
//    VO[ 7]   VO[ 8]   VO[ 9]   VO[10]   VO[11]   VO[12]   VO[13]   d()/dp1          //
//    VO[14]   VO[15]   VO[16]   VO[17]   VO[18]   VO[19]   VO[20]   d()/dp2          //
//    ...........................................................    d()/dpND         //
//                                                                                    //
// Output parameters:                                                                 //
//                                                                                    //
//    VO   -  output parameters and derivatives after propogation in magnetic field   //
//            defined by Mfield (KGauss)                                              //
//    Where a Mfield(R,H) - is interface to magnetic field information                //
//    input  R[ 0],R[ 1],R[ 2] - X     , Y      and Z  of the track                   //
//    output H[ 0],H[ 1],H[ 2] - Hx    , Hy     and Hz of the magnetic field          //
//           H[ 3],H[ 4],H[ 5] - dHx/dx, dHx/dy and dHx/dz                            //
//           H[ 6],H[ 7],H[ 8] - dHy/dx, dHy/dy and dHy/dz                            //
//           H[ 9],H[10],H[11] - dHz/dx, dHz/dy and dHz/dz                            //
//                                                                                    //
//    Path - trajectory length                                                        //
//                                                                                    //
// Authors: R.Brun, M.Hansroul, V.Perevoztchikov (Geant3)                             //
//                                                                                    //
// Porting to C++, new interface and Jacobian calculation                             // 
// had been done by Igor.Gavrilenko@cern.ch                                           //
//                                                                                    //
// Minor modification by Sergei.Gerassimov@cern.ch for use in Traffic and Phast       //
//                                                                                    //
// Here is assumed, that field is smooth enough i.e. field gradients are negligible   //
//------------------------------------------------------------------------------------//

References PaSetup::Ref().

double PaAlgo::W2	(	const TLorentzVector &	pmu0,
		const TLorentzVector &	pmu,
		double	m_P = `0.93827231`
	)			`[inline, static]`

W² via Lorentz vectors.

Parameters:

	pmu0	the beam Lorentz vector
	pmu	the scattered particle Lorentz vector
	m_P	the mass of the target particle (default is proton)

Author:: Alexandre.Korzenev@cern.ch

References W2().

double PaAlgo::W2	(	const TVector3 &	pmu0,
		const TVector3 &	pmu,
		double	m_P = `0.93827231`,
		double	mmu = `0.105658357`
	)			`[inline, static]`

W² via 3-vectors.

Parameters:

	pmu0	the beam vector
	pmu	the scattered particle vector
	m_P	the mass of the target particle (default is proton)
	mmu	the mass of the scattering particle (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E(), and Q2().

double PaAlgo::W2	(	double	pmu0,
		double	pmu,
		double	Cos,
		double	m_P = `0.93827231`,
		double	mmu = `0.105658357`
	)			`[inline, static]`

W² via momenta and Cos.

Parameters:

	pmu0	the absolute value of the beam momentum
	pmu	the absolute value of the scattered lepton momentum
	Cos	the cos of angle between beam and scattered lepton
	m_P	the mass of the target particle (default is proton)
	mmu	the mass of the scattering particle (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E(), and Q2().

Referenced by W2().

double PaAlgo::xbj	(	const TLorentzVector &	pmu0,
		const TLorentzVector &	pmu,
		double	m_P = `0.93827231`
	)			`[inline, static]`

x_Bjorken via Lorentz vectors

Parameters:

	pmu0	the beam Lorentz vector
	pmu	the scattered particle Lorentz vector
	m_P	the mass of the target particle (default is proton)

Author:: Alexandre.Korzenev@cern.ch

References xbj().

double PaAlgo::xbj	(	const TVector3 &	pmu0,
		const TVector3 &	pmu,
		double	m_P = `0.93827231`,
		double	mmu = `0.105658357`
	)			`[inline, static]`

x_Bjorken via 3-vectors

Parameters:

	pmu0	the beam vector
	pmu	the scattered particle vector
	m_P	the mass of the target particle (default is proton)
	mmu	the mass of the scattering particle (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E(), and Q2().

double PaAlgo::xbj	(	double	pmu0,
		double	pmu,
		double	Cos,
		double	m_P = `0.93827231`,
		double	mmu = `0.105658357`
	)			`[inline, static]`

x_Bjorken via momenta and Cos

Parameters:

	pmu0	the absolute value of the beam momentum
	pmu	the absolute value of the scattered lepton momentum
	Cos	the cos of angle between beam and scattered lepton
	m_P	the mass of the target particle (default is proton)
	mmu	the mass of the scattering particle (default is muon)

Author:: Alexandre.Korzenev@cern.ch

References E(), and Q2().

Referenced by xbj().

double PaAlgo::Xf	(	const TLorentzVector &	pmu0,
		const TLorentzVector &	pmu,
		const TLorentzVector &	plh,
		double	m_P = `0.93827231`
	)			`[inline, static]`

x_F via Lorentz vectors

Parameters:

	pmu0	the beam four-vector
	pmu	the scattered lepton four-vector
	plh	the hadron four-vector
	m_P	the target particle mass (default is proton)

Author:: Alexandre.Korzenev@cern.ch

References Xf().

double PaAlgo::Xf	(	const TVector3 &	pmu0,
		const TVector3 &	pmu,
		const TVector3 &	plh,
		double	mh = `0.13957018`,
		double	m_P = `0.93827231`,
		double	mmu = `0.105658357`
	)			`[inline, static]`

x_F via 3-vectors

Parameters:

	pmu0	the beam vector
	pmu	the scattered lepton vector
	plh	the hadron vector
	mh	the hadron mass
	m_P	the target paticle mass (default is proton)
	mmu	the lepton mass

Author:: Alexandre.Korzenev@cern.ch

References E(), and M().

Referenced by Xf().

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

lib/PaAlgo.h
lib/PaAlgo.cc
lib/PaAlgoComb.cc
lib/PaAlgoFindVtx.cc
lib/PaAlgoInv5.cc
lib/PaAlgoRKutta.cc

PaAlgo Class Reference

Static Public Member Functions

Detailed Description

Member Function Documentation