PYTHIA  8.303
Public Member Functions | Protected Attributes | Static Protected Attributes | List of all members
StringPT Class Reference

The StringPT class is used to select select transverse momenta. More...

#include <FragmentationFlavZpT.h>

Inheritance diagram for StringPT:
PhysicsBase HVStringPT

Public Member Functions

 StringPT ()
 Constructor.
 
virtual ~StringPT ()
 Destructor.
 
virtual void init ()
 Initialize data members. More...
 
pair< double, double > pxy (int idIn, double nNSP=0.0)
 
pair< double, double > pxyGauss (int idIn=0, double nNSP=0.0)
 
pair< double, double > pxyThermal (int idIn, double nNSP=0.0)
 
double suppressPT2 (double pT2)
 Gaussian suppression of given pT2; used in MiniStringFragmentation.
 
- Public Member Functions inherited from PhysicsBase
void initInfoPtr (Info &infoPtrIn)
 This function is called from above for physics objects used in a run. More...
 
virtual ~PhysicsBase ()
 Empty virtual destructor.
 
bool flag (string key) const
 Shorthand to read settings values.
 
int mode (string key) const
 
double parm (string key) const
 
string word (string key) const
 

Protected Attributes

bool useWidthPre
 
double sigmaQ
 
double enhancedFraction
 
double enhancedWidth
 
double sigma2Had
 
double widthPreStrange
 
double widthPreDiquark
 
bool thermalModel
 Thermal model.
 
double temperature
 
double tempPreFactor
 
double fracSmallX
 
bool closePacking
 Both.
 
double exponentMPI
 
double exponentNSP
 
- Protected Attributes inherited from PhysicsBase
InfoinfoPtr = {}
 
SettingssettingsPtr = {}
 Pointer to the settings database.
 
ParticleDataparticleDataPtr = {}
 Pointer to the particle data table.
 
HadronWidthshadronWidthsPtr = {}
 Pointer to the hadron widths data table.
 
RndmrndmPtr = {}
 Pointer to the random number generator.
 
CoupSMcoupSMPtr = {}
 Pointers to SM and SUSY couplings.
 
CoupSUSYcoupSUSYPtr = {}
 
BeamParticlebeamAPtr = {}
 
BeamParticlebeamBPtr = {}
 
BeamParticlebeamPomAPtr = {}
 
BeamParticlebeamPomBPtr = {}
 
BeamParticlebeamGamAPtr = {}
 
BeamParticlebeamGamBPtr = {}
 
BeamParticlebeamVMDAPtr = {}
 
BeamParticlebeamVMDBPtr = {}
 
PartonSystemspartonSystemsPtr = {}
 Pointer to information on subcollision parton locations.
 
SigmaTotalsigmaTotPtr = {}
 Pointer to the total/elastic/diffractive cross sections.
 
set< PhysicsBase * > subObjects
 
UserHooksPtr userHooksPtr
 

Static Protected Attributes

static const double SIGMAMIN = 0.2
 Constants: could only be changed in the code itself. More...
 

Additional Inherited Members

- Public Types inherited from PhysicsBase
enum  Status {
  INCOMPLETE = -1, COMPLETE = 0, CONSTRUCTOR_FAILED, INIT_FAILED,
  LHEF_END, LOWENERGY_FAILED, PROCESSLEVEL_FAILED, PROCESSLEVEL_USERVETO,
  MERGING_FAILED, PARTONLEVEL_FAILED, PARTONLEVEL_USERVETO, HADRONLEVEL_FAILED,
  CHECK_FAILED, OTHER_UNPHYSICAL, HEAVYION_FAILED
}
 Enumerate the different status codes the event generation can have.
 
- Protected Member Functions inherited from PhysicsBase
 PhysicsBase ()
 Default constructor.
 
virtual void onInitInfoPtr ()
 
virtual void onBeginEvent ()
 This function is called in the very beginning of each Pythia::next call.
 
virtual void onEndEvent (Status)
 
virtual void onStat ()
 This function is called from the Pythia::stat() call.
 
void registerSubObject (PhysicsBase &pb)
 Register a sub object that should have its information in sync with this.
 

Detailed Description

The StringPT class is used to select select transverse momenta.

Member Function Documentation

void init ( )
virtual

Initialize data members.

Initialize data members of the string pT selection.

Parameters of the pT width and enhancement.

Temperature for thermal model.

Upper estimate of thermal spectrum: fraction at x = pT_quark/T < 1.

Enhanded-width prefactor for MPIs and/or nearby string pieces.

Parameter for pT suppression in MiniStringFragmentation.

Reimplemented in HVStringPT.

pair<double, double> pxy ( int  idIn,
double  nNSP = 0.0 
)
inline

General function, return px and py as a pair in the same call in either model.

pair< double, double > pxyGauss ( int  idIn = 0,
double  nNSP = 0.0 
)

Generate Gaussian pT such that <p_x^2> = <p_x^2> = sigma^2 = width^2/2, but with small fraction multiplied up to a broader spectrum.

Normal (classical) width selection.

Prefactor for strange quarks and diquarks.

Enhanded-width prefactor for MPIs and/or nearby string pieces.

Generate (p_x, p_y) pair.

pair< double, double > pxyThermal ( int  idIn,
double  nNSP = 0.0 
)

Generate quark pT according to fitting functions, such that hadron pT is generated according to exp(-pT/T) d^2pT.

Temperature increase to work against asymmetry. Apply for s/c/b and diquarks.

Enhanded-width prefactor for MPIs and/or nearby string pieces.

Pick x = pT_quark/T according to K_{1/4}(x)/x^{1/4} * x dx.

Find pT_quark. Random number to decide on angle.

Done.

Member Data Documentation

const double SIGMAMIN = 0.2
staticprotected

Constants: could only be changed in the code itself.

The StringPT class.

Constants: could be changed here if desired, but normally should not. These are of technical nature, as described for each. To avoid division by zero one must have sigma > 0.

bool useWidthPre
protected

Initialization data, to be read from Settings. Gaussian model.


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