PYTHIA  8.305
Public Member Functions | Protected Member Functions | List of all members
Sigma1Process Class Reference

#include <SigmaProcess.h>

Inheritance diagram for Sigma1Process:
SigmaProcess PhysicsBase Sigma1ffbar2gmZ Sigma1ffbar2GravitonStar Sigma1ffbar2H Sigma1ffbar2Hchg Sigma1ffbar2Rhorizontal Sigma1ffbar2W Sigma1ffbar2WRight Sigma1ffbar2Zp2XX Sigma1ffbar2ZRight Sigma1ffbar2Zv Sigma1ffbarZprimeWprime Sigma1gg2GravitonStar Sigma1gg2H Sigma1gg2S2XX Sigma1gmgm2H Sigma1lgm2lStar Sigma1ll2Hchgchg Sigma1qg2qStar Sigma1ql2LeptoQuark Sigma1qq2antisquark Sigma1qqbar2KKgluonStar

Public Member Functions

virtual ~Sigma1Process ()
virtual int nFinal () const
 Number of final-state particles.
virtual void set1Kin (double x1in, double x2in, double sHin)
 Input and complement kinematics for resolved 2 -> 1 process.
virtual double sigmaHat ()
 Evaluate sigmaHat(sHat) for resolved 2 -> 1 processes.
virtual double sigmaHatWrap (int id1in=0, int id2in=0)
- Public Member Functions inherited from SigmaProcess
virtual ~SigmaProcess ()
void init (BeamParticle *beamAPtrIn, BeamParticle *beamBPtrIn, SLHAinterface *slhaInterfacePtrIn=0)
 Perform simple initialization and store pointers. More...
void setLHAPtr (LHAupPtr lhaUpPtrIn)
 Store or replace Les Houches pointer.
virtual void initProc ()
 Initialize process. Only used for some processes.
virtual bool initFlux ()
 Set up allowed flux of incoming partons. Default is no flux. More...
virtual void set2Kin (double, double, double, double, double, double, double, double)
virtual void set2KinMPI (double, double, double, double, double, double, double, bool, double, double)
virtual void set3Kin (double, double, double, Vec4, Vec4, Vec4, double, double, double, double, double, double)
virtual void sigmaKin ()
 Calculate flavour-independent parts of cross section.
virtual double sigmaPDF (bool initPS=false, bool samexGamma=false, bool useNewXvalues=false, double x1New=0., double x2New=0.)
void pickInState (int id1in=0, int id2in=0)
 Select incoming parton channel and extract parton densities (resolved). More...
virtual void setIdColAcol ()
 Select flavour, colour and anticolour.
virtual bool final2KinMPI (int=0, int=0, Vec4=0., Vec4=0., double=0., double=0.)
 Perform kinematics for a Multiparton Interaction, in its rest frame.
virtual double weightDecay (Event &, int, int)
virtual void setScale ()
 Set scale, when that is missing for an external LHA process.
virtual string name () const
 Process name and code, and the number of final-state particles.
virtual int code () const
virtual string inFlux () const
 Need to know which incoming partons to set up interaction for.
virtual bool convert2mb () const
 Need to know whether to convert cross section answer from GeV^-2 to mb.
virtual bool convertM2 () const
 For 2 -> 2 process optional conversion from |M|^2 to d(sigmaHat)/d(tHat).
virtual bool isLHA () const
 Special treatment needed for Les Houches processes.
virtual bool isNonDiff () const
 Special treatment needed for elastic and diffractive processes.
virtual bool isResolved () const
virtual bool isDiffA () const
virtual bool isDiffB () const
virtual bool isDiffC () const
virtual bool isSUSY () const
 Special treatment needed for SUSY processes.
virtual bool allowNegativeSigma () const
 Special treatment needed if negative cross sections allowed.
virtual int id3Mass () const
virtual int id4Mass () const
virtual int id5Mass () const
virtual int resonanceA () const
 Special treatment needed if process contains an s-channel resonance.
virtual int resonanceB () const
virtual bool isSChannel () const
 2 -> 2 and 2 -> 3 processes only through s-channel exchange.
virtual int idSChannel () const
 NOAM: Insert an intermediate resonance in 2 -> 1 -> 2 (or 3) listings.
virtual bool isQCD3body () const
 QCD 2 -> 3 processes need special phase space selection machinery.
virtual int idTchan1 () const
 Special treatment in 2 -> 3 with two massive propagators.
virtual int idTchan2 () const
virtual double tChanFracPow1 () const
virtual double tChanFracPow2 () const
virtual bool useMirrorWeight () const
virtual int gmZmode () const
 Special process-specific gamma*/Z0 choice if >=0 (e.g. f fbar -> H0 Z0).
bool swappedTU () const
 Tell whether tHat and uHat are swapped (= same as swap 3 and 4).
int id (int i) const
 Give back particle properties: flavours, colours, masses, or all.
int col (int i) const
int acol (int i) const
double m (int i) const
Particle getParton (int i) const
double Q2Ren () const
double alphaEMRen () const
double alphaSRen () const
double Q2Fac () const
double pdf1 () const
double pdf2 () const
double thetaMPI () const
 Give back angles; relevant only for multipe-interactions processes.
double phiMPI () const
double sHBetaMPI () const
double pT2MPI () const
double pTMPIFin () const
void saveKin ()
 Save and load kinematics for trial interactions.
void loadKin ()
void swapKin ()
virtual void setIdInDiff (int, int)
 Set the incoming ids for diffraction.
- 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 Member Functions

 Sigma1Process ()
virtual void store1Kin (double x1in, double x2in, double sHin)
 Store kinematics and set scales for resolved 2 -> 1 process. More...
virtual bool setupForME ()
 Calculate modified masses and four-vectors for matrix elements. More...
- Protected Member Functions inherited from SigmaProcess
 SigmaProcess ()
void addBeamA (int idIn)
void addBeamB (int idIn)
int sizeBeamA () const
int sizeBeamB () const
void addPair (int idAIn, int idBIn)
int sizePair () const
bool setupForMEin ()
 Calculate incoming modified masses and four-vectors for matrix elements. More...
void setId (int id1in=0, int id2in=0, int id3in=0, int id4in=0, int id5in=0)
 Set flavour, colour and anticolour.
void setColAcol (int col1=0, int acol1=0, int col2=0, int acol2=0, int col3=0, int acol3=0, int col4=0, int acol4=0, int col5=0, int acol5=0)
void swapColAcol ()
void swapCol1234 ()
void swapCol12 ()
void swapCol34 ()
double weightTopDecay (Event &process, int iResBeg, int iResEnd)
 Common code for top and Higgs secondary decay angular weights. More...
double weightHiggsDecay (Event &process, int iResBeg, int iResEnd)
- 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.

Additional Inherited Members

- Public Types inherited from PhysicsBase
enum  Status {
 Enumerate the different status codes the event generation can have.
- Public Attributes inherited from SigmaProcess
Z0 gamma *Z0Usage: weightDecayFlav( process). */ virtual double weightDecayFlav( Event&) {return 1.
- Protected Attributes inherited from SigmaProcess
 Pointer to an SLHA object.
LHAupPtr lhaUpPtr
 Pointer to LHAup for generating external events.
int nQuarkIn
 Initialization data, normally only set once.
int renormScale1
int renormScale2
int renormScale3
int renormScale3VV
int factorScale1
int factorScale2
int factorScale3
int factorScale3VV
double Kfactor
double mcME
double mbME
double mmuME
double mtauME
double renormMultFac
double renormFixScale
double factorMultFac
double factorFixScale
int higgsH1parity
 CP violation parameters for Higgs sector, normally only set once.
int higgsH2parity
int higgsA3parity
double higgsH1eta
double higgsH2eta
double higgsA3eta
double higgsH1phi
double higgsH2phi
double higgsA3phi
int idA
 Information on incoming beams.
int idB
double mA
double mB
bool isLeptonA
bool isLeptonB
bool hasLeptonBeams
bool beamA2gamma
bool beamB2gamma
bool hasGamma
vector< InBeaminBeamA
 Partons in beams, with PDF's.
vector< InBeaminBeamB
vector< InPairinPair
 Allowed colliding parton pairs, with pdf's.
double mH
 Store common subprocess kinematics quantities.
double sH
double sH2
double Q2RenSave
 Store Q2 renormalization and factorization scales, and related values.
double alpEM
double alpS
double Q2FacSave
double x1Save
double x2Save
double pdf1Save
double pdf2Save
double sigmaSumSave
int id1
 Store flavour, colour, anticolour, mass, angles and the whole particle.
int id2
int id3
int id4
int id5
int idSave [12]
int colSave [12]
int acolSave [12]
double mSave [12]
double cosTheta
double sinTheta
double phi
double sHMass
double sHBeta
double pT2Mass
double pTFin
Particle parton [12]
Particle partonT [12]
double mSaveT [12]
double pTFinT
double cosThetaT
double sinThetaT
double phiT
double mME [12]
Vec4 pME [12]
bool swapTU
 Store whether tHat and uHat are swapped (= same as swap 3 and 4).
- 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 inherited from SigmaProcess
static const double CONVERT2MB = 0.389380
 Constants: could only be changed in the code itself. More...
static const double MASSMARGIN = 0.1
 The sum of outgoing masses must not be too close to the cm energy.
static const double COMPRELERR = 1e-10
static const int NCOMPSTEP = 10

Detailed Description

Sigma1Process is the base class for 2 -> 1 processes. It is derived from SigmaProcess.

Member Function Documentation

bool setupForME ( )

Calculate modified masses and four-vectors for matrix elements.

Common initial-state handling.

Final state trivial here.


Reimplemented from SigmaProcess.

double sigmaHatWrap ( int  id1in = 0,
int  id2in = 0 

Wrapper to sigmaHat, to (a) store current incoming flavours, (b) convert from GeV^-2 to mb where required, and (c) convert from |M|^2 to d(sigmaHat)/d(tHat) where required.

The Sigma1Process class. Base class for resolved 2 -> 1 cross sections; derived from SigmaProcess. Wrapper to sigmaHat, to (a) store current incoming flavours, (b) convert from GeV^-2 to mb where required, and (c) convert from |M|^2 to d(sigmaHat)/d(tHat) where required.

Convert 2 * pi * delta(p^2 - m^2) to Breit-Wigner with same area.

Reimplemented from SigmaProcess.

void store1Kin ( double  x1in,
double  x2in,
double  sHin 

Store kinematics and set scales for resolved 2 -> 1 process.

Input and complement kinematics for resolved 2 -> 1 process.

Default value only sensible for these processes.

Incoming parton momentum fractions and sHat.

Different options for renormalization scale, but normally sHat.

Different options for factorization scale, but normally sHat.

Evaluate alpha_strong and alpha_EM.

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