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

#include <UserHooks.h>

Inheritance diagram for SuppressSmallPT:
UserHooks PhysicsBase

Public Member Functions

 SuppressSmallPT (double pT0timesMPIIn=1., int numberAlphaSIn=0, bool useSameAlphaSasMPIIn=true)
virtual bool canModifySigma ()
 Possibility to modify cross section of process.
virtual double multiplySigmaBy (const SigmaProcess *sigmaProcessPtr, const PhaseSpace *phaseSpacePtr, bool)
 The SuppressSmallPT class, derived from UserHooks. More...
- Public Member Functions inherited from UserHooks
virtual ~UserHooks ()
virtual bool initAfterBeams ()
 Initialisation after beams have been set by Pythia::init().
virtual bool canBiasSelection ()
 Possibility to bias selection of events, compensated by a weight.
virtual double biasSelectionBy (const SigmaProcess *sigmaProcessPtr, const PhaseSpace *phaseSpacePtr, bool inEvent)
 Multiplicative factor in the phase space selection of a hard process. More...
virtual double biasedSelectionWeight ()
 Event weight to compensate for selection weight above.
virtual bool canVetoProcessLevel ()
 Possibility to veto event after process-level selection.
virtual bool doVetoProcessLevel (Event &)
virtual bool canVetoResonanceDecays ()
 Possibility to veto resonance decay chain.
virtual bool doVetoResonanceDecays (Event &)
virtual bool canVetoPT ()
virtual double scaleVetoPT ()
 Transverse-momentum scale for veto test.
virtual bool doVetoPT (int, const Event &)
virtual bool canVetoStep ()
virtual int numberVetoStep ()
 Up to how many ISR + FSR steps of hardest interaction should be checked.
virtual bool doVetoStep (int, int, int, const Event &)
virtual bool canVetoMPIStep ()
virtual int numberVetoMPIStep ()
 Up to how many MPI steps should be checked.
virtual bool doVetoMPIStep (int, const Event &)
virtual bool canVetoPartonLevelEarly ()
virtual bool doVetoPartonLevelEarly (const Event &)
virtual bool retryPartonLevel ()
virtual bool canVetoPartonLevel ()
 Possibility to veto event after parton-level selection.
virtual bool doVetoPartonLevel (const Event &)
virtual bool canSetResonanceScale ()
 Possibility to set initial scale in TimeShower for resonance decay.
virtual double scaleResonance (int, const Event &)
virtual bool canVetoISREmission ()
 Possibility to veto an emission in the ISR machinery.
virtual bool doVetoISREmission (int, const Event &, int)
virtual bool canVetoFSREmission ()
 Possibility to veto an emission in the FSR machinery.
virtual bool doVetoFSREmission (int, const Event &, int, bool=false)
virtual bool canVetoMPIEmission ()
 Possibility to veto an MPI.
virtual bool doVetoMPIEmission (int, const Event &)
virtual bool canReconnectResonanceSystems ()
 Possibility to reconnect colours from resonance decay systems.
virtual bool doReconnectResonanceSystems (int, Event &)
virtual bool canEnhanceEmission ()
 Enhance emission rates (sec. 4 in EPJC (2013) 73).
virtual double enhanceFactor (string)
virtual double vetoProbability (string)
void setEnhancedEventWeight (double wt)
double getEnhancedEventWeight ()
virtual bool canEnhanceTrial ()
void setEnhancedTrial (double pTIn, double wtIn)
double getEnhancedTrialPT ()
double getEnhancedTrialWeight ()
virtual bool canChangeFragPar ()
 Can change fragmentation parameters.
virtual void setStringEnds (const StringEnd *, const StringEnd *, vector< int >)
virtual bool doChangeFragPar (StringFlav *, StringZ *, StringPT *, int, double, vector< int >, const StringEnd *)
virtual bool doVetoFragmentation (Particle, const StringEnd *)
virtual bool doVetoFragmentation (Particle, Particle, const StringEnd *, const StringEnd *)
virtual bool canSetImpactParameter () const
 Can set the overall impact parameter for the MPI treatment.
virtual double doSetImpactParameter ()
 Set the overall impact parameter for the MPI treatment.
- 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

Additional Inherited Members

- Public Types inherited from PhysicsBase
enum  Status {
 Enumerate the different status codes the event generation can have.
- Protected Member Functions inherited from UserHooks
 UserHooks ()
virtual void onInitInfoPtr () override
 After initInfoPtr, initialize workEvent. More...
void omitResonanceDecays (const Event &process, bool finalOnly=false)
 omitResonanceDecays omits resonance decay chains from process record. More...
void subEvent (const Event &event, bool isHardest=true)
 subEvent extracts currently resolved partons in the hard process. More...
- Protected Member Functions inherited from PhysicsBase
 PhysicsBase ()
 Default constructor.
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.
- Protected Attributes inherited from UserHooks
Event workEvent = {}
 Have one event object around as work area.
double selBias = 1.
 User-imposed selection bias.
double enhancedEventWeight = {}
 Bookkept quantities for boosted event weights.
double pTEnhanced = {}
double wtEnhanced = {}
- 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

Detailed Description

SuppressSmallPT is a derived class for user access to program execution. It is a simple example, illustrating how to suppress the cross section of 2 -> 2 processes by a factor pT^4 / (pT0^2 + pT^2)^2, with pT0 input, and also modify alpha_strong scale similarly.

Member Function Documentation

double multiplySigmaBy ( const SigmaProcess sigmaProcessPtr,
const PhaseSpace phaseSpacePtr,

The SuppressSmallPT class, derived from UserHooks.

Multiplicative factor modifying the cross section of a hard process. Usage: inEvent is true for event generation, false for initialization.

Modify event weight at the trial level, before selection.

Need to initialize first time this method is called.

Calculate pT0 as for multiparton interactions. Fudge factor allows offset relative to MPI framework.

Initialize alpha_strong object as for multiparton interactions, alternatively as for hard processes.

Initialization finished.

Only modify 2 -> 2 processes.

pT scale of process. Weight pT^4 / (pT^2 + pT0^2)^2

Renormalization scale and assumed alpha_strong.

Reweight to new alpha_strong at new scale.

End weight calculation.

Reimplemented from UserHooks.

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