PYTHIA  8.303
Public Member Functions | List of all members
SigmaABMST Class Reference

#include <SigmaTotal.h>

Inheritance diagram for SigmaABMST:
SigmaTotAux

Public Member Functions

 SigmaABMST ()
 Constructor.
 
virtual void init (Info *infoPtrIn)
 Initialize data members. More...
 
virtual bool calcTotEl (int idAin, int idBin, double sIn, double, double)
 Calculate integrated total/elastic cross sections. More...
 
virtual double dsigmaEl (double t, bool useCoulomb=false, bool onlyPomerons=false)
 Differential elastic cross section.
 
virtual bool calcDiff (int idAin, int idBin, double sIn, double, double)
 Calculate integrated diffractive cross sections. More...
 
virtual double dsigmaSD (double xi, double t, bool=true, int=0)
 Differential single diffractive cross section. More...
 
virtual double dsigmaDD (double xi1, double xi2, double t, int=0)
 Differential double diffractive cross section. More...
 
virtual double dsigmaCD (double xi1, double xi2, double t1, double t2, int=0)
 Differential central diffractive cross section. More...
 
virtual double mMinCD ()
 Minimal central diffractive mass.
 
- Public Member Functions inherited from SigmaTotAux
 SigmaTotAux ()
 Constructor.
 
virtual ~SigmaTotAux ()
 Destructor.
 
virtual bool splitDiff ()
 Possibility to separate xi and t choices for diffraction.
 
pair< double, double > tRange (double sIn, double s1In, double s2In, double s3In, double s4In)
 
bool tInRange (double tIn, double sIn, double s1In, double s2In, double s3In, double s4In)
 
double pFormFac (double tIn)
 Commonly used proton form factor.
 

Additional Inherited Members

- Public Attributes inherited from SigmaTotAux
bool isExpEl
 Store total and elastic cross section properties.
 
bool hasCou
 
double sigTot
 
double rhoOwn
 
double sigEl
 
double bEl
 
double sigTotCou
 
double sigElCou
 
double sigXB
 Store diffractive cross sections.
 
double sigAX
 
double sigXX
 
double sigAXB
 
- Protected Member Functions inherited from SigmaTotAux
virtual bool initCoulomb (Settings &settings, ParticleData *particleDataPtrIn)
 Initialize Coulomb correction parameters. More...
 
virtual bool addCoulomb ()
 Add Coulomb corrections to the elastic and total cross sections. More...
 
virtual double dsigmaElCoulomb (double t)
 Coulomb contribution to the differential elastic cross sections. More...
 
- Protected Attributes inherited from SigmaTotAux
int idA
 Initialization data, normally only set once.
 
int idB
 
bool tryCoulomb
 Add Coulomb corrections to the elastic cross section.
 
double chgSgn
 
double tAbsMin
 
double lambda
 
double phaseCst
 
ParticleDataparticleDataPtr
 Pointer to the particle data table.
 
RndmrndmPtr
 Pointer to the random number generator.
 
- Static Protected Attributes inherited from SigmaTotAux
static const int NPOINTS = 1000
 Constants: could only be changed in the code itself. More...
 
static const double ALPHAEM = 0.00729353
 alpha_em(0). More...
 
static const double CONVERTEL = 0.0510925
 Conversion coefficients = 1/(16pi) * (mb <-> GeV^2).
 
static const double MPROTON = 0.9382720
 Proton and pion masses, and their squares. Euler's constant.
 
static const double SPROTON = 0.8803544
 
static const double MPION = 0.1349766
 
static const double SPION = 0.0182187
 
static const double GAMMAEUL = 0.577215665
 
static const double TABSREF = 2e-3
 Reference scale for nominal definition of t slope.
 
static const double TABSMAX = 1.
 
static const double MINSLOPEEL = 10.
 

Detailed Description

The SigmaABMST class parametrizes total and elastic cross sections according to Appleby, Barlow, Molson, Serluca and Toader (ABMST).

Member Function Documentation

bool calcDiff ( int  idAin,
int  idBin,
double  sIn,
double  ,
double   
)
virtual

Calculate integrated diffractive cross sections.

Diffractive cross sections.

Find appropriate combination of incoming beams.

Total cross section needed for central diffraction.

Single diffractive cross sections by grid integration.

Double diffractive cross section by Monte Carlo or grid integration.

Central diffractive cross section by Monte Carlo integration.

Done.

Reimplemented from SigmaTotAux.

bool calcTotEl ( int  idAin,
int  idBin,
double  sIn,
double  ,
double   
)
virtual

Calculate integrated total/elastic cross sections.

Calculate total and (integrated) elastic cross sections.

Find appropriate combination of incoming beams.

Total cross section and the rho parameter using the full expression.

Total elastic cross section, by integration in exp( MINSLOPEEL * t).

Approximate exponential slope.

Done if no Coulomb corrections.

Reduce hadronic part of elastic cross section by tMin cut.

Loop through t range according to dt/t^2.

Evaluate cross section difference between with and without Coulomb.

Include common factors to give new elastic and total cross sections.

Done.

Reimplemented from SigmaTotAux.

double dsigmaCD ( double  xi1,
double  xi2,
double  t1,
double  t2,
int  = 0 
)
virtual

Differential central diffractive cross section.

ABMST valid for |t| < 4.

dSigma_CD(x1, x2, t1, t2) = dSigma_SD(x1, t1) * dSigma_SD(x2, t2) / sigma_tot.

Minimal fall-off relative to t = 0 value.

Optionally dampen with 1 / (1 + exp( -p * (y - y_gap))) for both gaps.

Optionally multiply by s-dependent factor.

Done.

Reimplemented from SigmaTotAux.

double dsigmaDD ( double  xi1,
double  xi2,
double  t,
int  = 0 
)
virtual

Differential double diffractive cross section.

Calculate mass and check it is above threshold. ABMST valid for |t| < 4.

dSigma_DD(x1, x2, t) = dSigma_SD(x1, t) * dSigma_SD(x2, t) / dSigma_el(t). Elastic using only Pomerons.

Minimal fall-off relative to t = 0 value.

Optionally dampen with 1 / (1 + exp( -p * (y - y_gap))).

Optionally multiply by s-dependent factor.

Done.

Reimplemented from SigmaTotAux.

double dsigmaSD ( double  xi,
double  t,
bool  = true,
int  = 0 
)
virtual

Differential single diffractive cross section.

Variations on differential SD cross sections xi * dsigma / dxi dt.

Calculate core SD cross section.

Optionally require falloff at least like exp(bMin * t);

Optionally dampen with 1 / (1 + exp( -p * (y - y_gap))).

Optionally multiply by s-dependent factor.

Done.

Reimplemented from SigmaTotAux.

void init ( Info infoPtrIn)
virtual

Initialize data members.

Use shorthand for settings

Save pointer.

Common setup.

Allow Couplomb corrections for elastic scattering.

Setup for single diffraction.

Setup for double diffraction.

Setup for central diffraction.

Setup to dampen diffractive events with small rapidity gaps.

Setup to force minimal t fall-off like exp(b_min * t).

Implements SigmaTotAux.


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