PYTHIA  8.305
Public Member Functions | Public Attributes | Protected Member Functions | Protected Attributes | Static Protected Attributes | List of all members
SigmaProcess Class Reference

SigmaProcess is the base class for cross section calculations. More...

#include <SigmaProcess.h>

Inheritance diagram for SigmaProcess:
PhysicsBase Sigma0Process Sigma1Process Sigma2Process Sigma3Process SigmaLHAProcess Sigma0AB2AB Sigma0AB2AX Sigma0AB2AXB Sigma0AB2XB Sigma0AB2XX Sigma0nonDiffractive Sigma1ffbar2gmZ Sigma1ffbar2GravitonStar Sigma1ffbar2H Sigma1ffbar2Hchg Sigma1ffbar2Rhorizontal Sigma1ffbar2W Sigma1ffbar2WRight Sigma1ffbar2Zp2XX Sigma1ffbar2ZRight Sigma1ffbar2Zv Sigma1ffbarZprimeWprime Sigma1gg2GravitonStar Sigma1gg2H Sigma1gg2S2XX Sigma1gmgm2H Sigma1lgm2lStar Sigma1ll2Hchgchg Sigma1qg2qStar Sigma1ql2LeptoQuark Sigma1qq2antisquark Sigma1qqbar2KKgluonStar Sigma2ff2fftgmZ Sigma2ff2fftW Sigma2ffbar2A3H12 Sigma2ffbar2ffbarsgm Sigma2ffbar2ffbarsgmZ Sigma2ffbar2FFbarsgmZ Sigma2ffbar2ffbarsW Sigma2ffbar2FfbarsW Sigma2ffbar2fGfGbar Sigma2ffbar2gammagamma Sigma2ffbar2HchgchgHchgchg Sigma2ffbar2HchgH12 Sigma2ffbar2HposHneg Sigma2ffbar2HW Sigma2ffbar2HZ Sigma2ffbar2LEDgammagamma Sigma2ffbar2LEDllbar Sigma2ffbar2LEDUnparticlegamma Sigma2ffbar2LEDUnparticleZ Sigma2ffbar2TEVffbar Sigma2ffbar2ZpH Sigma2ffbargmZggm Sigma2ffbargmZWgmZW Sigma2ffbarWggm Sigma2gg2gammagamma Sigma2gg2gg Sigma2gg2ggamma Sigma2gg2GravitonStarg Sigma2gg2Hglt Sigma2gg2LEDgammagamma Sigma2gg2LEDgg Sigma2gg2LEDllbar Sigma2gg2LEDqqbar Sigma2gg2LEDUnparticleg Sigma2gg2LQLQbar Sigma2gg2qGqGbar Sigma2gg2QQbar Sigma2gg2qqbar Sigma2gg2QQbar3PJ1g Sigma2gg2QQbar3S11g Sigma2gg2QQbar3S11gm Sigma2gg2QQbar3S11QQbar3S11 Sigma2gg2QQbarX8g Sigma2gg2Sg2XXj Sigma2ggm2qqbar Sigma2gmgm2ffbar Sigma2lgm2Hchgchgl Sigma2QCffbar2llbar Sigma2QCqq2qq Sigma2QCqqbar2qqbar Sigma2qg2GravitonStarq Sigma2qg2Hchgq Sigma2qg2Hq Sigma2qg2Hqlt Sigma2qg2LEDqg Sigma2qg2LEDUnparticleq Sigma2qg2LeptoQuarkl Sigma2qg2qg Sigma2qg2qgamma Sigma2qgm2qg Sigma2qgm2qgm Sigma2qq2LEDqq Sigma2qq2qq Sigma2qq2QqtW Sigma2qq2qStarq Sigma2qqbar2DY Sigma2qqbar2gg Sigma2qqbar2ggamma Sigma2qqbar2GravitonStarg Sigma2qqbar2Hglt Sigma2qqbar2LEDgg Sigma2qqbar2LEDqqbarNew Sigma2qqbar2LEDUnparticleg Sigma2qqbar2LQLQbar Sigma2qqbar2lStarlbar Sigma2qqbar2lStarlStarBar Sigma2qqbar2qGqGbar Sigma2qqbar2QQbar Sigma2qqbar2QQbar3S11QQbar3S11 Sigma2qqbar2qqbarNew Sigma2qqbar2Zpg2XXj Sigma2SUSY Sigma3ff2HchgchgfftWW Sigma3ff2HfftWW Sigma3ff2HfftZZ Sigma3gg2ggg Sigma3gg2HQQbar Sigma3qq2qqgDiff Sigma3qq2qqgSame Sigma3qqbar2ggg Sigma3qqbar2HQQbar

Public Member Functions

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 set1Kin (double, double, double)
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 sigmaHat ()
virtual double sigmaHatWrap (int id1in=0, int id2in=0)
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 int nFinal () 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

Public Attributes

Z0 gamma *Z0Usage: weightDecayFlav( process). */ virtual double weightDecayFlav( Event&) {return 1.

Protected Member Functions

 SigmaProcess ()
void addBeamA (int idIn)
void addBeamB (int idIn)
int sizeBeamA () const
int sizeBeamB () const
void addPair (int idAIn, int idBIn)
int sizePair () const
virtual bool setupForME ()
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.

Protected Attributes

 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

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

Additional Inherited Members

- Public Types inherited from PhysicsBase
enum  Status {
 Enumerate the different status codes the event generation can have.

Detailed Description

SigmaProcess is the base class for cross section calculations.

Member Function Documentation

virtual int id3Mass ( ) const

Flavours in 2 -> 2/3 processes where masses needed from beginning. (For a light quark masses will be used in the final kinematics, but not at the matrix-element level. For a gluon no masses at all.)

Reimplemented in Sigma2ggm2qqbar, Sigma2gmgm2ffbar, Sigma2fgm2Wf, Sigma2ffbar2Wgm, Sigma2qg2Wq, Sigma2qqbar2Wg, Sigma2fgm2gmZf, Sigma2ffbar2gmZgm, Sigma2qg2gmZq, Sigma2qqbar2gmZg, Sigma2qqbar2sleptonantislepton, Sigma2ffbar2HposHneg, Sigma2ffbar2WW, Sigma2ffbar2HchgH12, Sigma2ffbar2ZW, Sigma2ffbar2A3H12, Sigma2qqbar2chi0gluino, Sigma2ffbar2gmZgmZ, Sigma2qg2Hchgq, Sigma2qqbar2gluinogluino, Sigma2qqbar2Hglt, Sigma2ffbar2FfbarsW, Sigma2gg2gluinogluino, Sigma2ffbar2LEDUnparticlegamma, Sigma2qg2Hqlt, Sigma2ffbar2FFbarsgmZ, Sigma2qg2squarkgluino, Sigma2ffbar2LEDUnparticleZ, Sigma2gg2Hglt, Sigma2gg2squarkantisquark, Sigma2qqbar2LEDUnparticleg, Sigma2qg2Hq, Sigma2qqbar2QQbar, Sigma2qqbar2QQbar3S11QQbar3S11, Sigma2qg2LEDUnparticleq, Sigma3qqbar2HQQbar, Sigma2qqbar2squarkantisquark, Sigma2gg2QQbar, Sigma2gg2QQbar3S11QQbar3S11, Sigma2gg2LEDUnparticleg, Sigma3gg2HQQbar, Sigma2qq2squarksquark, Sigma2ffbar2TEVffbar, Sigma3ff2HfftWW, Sigma2gg2QQbarX8g, Sigma2qqbar2DY, Sigma2qq2QqtW, Sigma2qqbar2GravitonStarg, Sigma3ff2HfftZZ, Sigma2ffbar2HchgchgHchgchg, Sigma2qg2GravitonStarq, Sigma2gg2Sg2XXj, Sigma2qg2chi0squark, Sigma2ffbar2HW, Sigma2qqbar2lStarlStarBar, Sigma3ff2HchgchgfftWW, Sigma2gg2GravitonStarg, Sigma2qqbar2lStarlbar, Sigma2ffbar2HZ, Sigma2gg2QQbar3PJ1g, Sigma2qqbar2LQLQbar, Sigma2ffbar2ZpH, Sigma2gg2QQbar3S11gm, Sigma2qq2qStarq, Sigma2ffbar2fGfGbar, Sigma2gg2LQLQbar, Sigma2gg2QQbar3S11g, Sigma2qqbar2qGqGbar, Sigma2qqbar2chi0chi0, Sigma2qqbar2Zpg2XXj, Sigma2qg2LeptoQuarkl, and Sigma2gg2qGqGbar.

void init ( BeamParticle beamAPtrIn,
BeamParticle beamBPtrIn,
SLHAinterface slhaInterfacePtrIn = 0 

Perform simple initialization and store pointers.

Beam pointers can differ from the main beam pointers in PhysicsBase.

Pointer to SLHA object allows semi-internal processes to access SLHA blocks via getEntry() methods, see arXiv:1109.5852

Read out some properties of beams to allow shorthand.

Photon sub-beams from leptons or hadrons.

K factor, multiplying resolved processes. (But not here for MPI.)

Maximum incoming quark flavour.

Medium heavy fermion masses set massless or not in ME expressions.

Renormalization scale choice.

Factorization scale choice.

CP violation parameters for the BSM Higgs sector.

If BSM not switched on then H1 should have SM properties.

bool initFlux ( )

Set up allowed flux of incoming partons. Default is no flux.

Set up allowed flux of incoming partons. addBeam: set up PDF's that need to be evaluated for the two beams. addPair: set up pairs of incoming partons from the two beams.

Reset arrays (in case of several init's in same run).

Read in process-specific channel information.

Case with g g incoming state.

Case with q g incoming state.

Case with q q', q qbar' or qbar qbar' incoming state.

Case with q qbar' incoming state.

Case with q qbar incoming state.

Case with f f', f fbar', fbar fbar' incoming state.

If beams are leptons then they are also the colliding partons unless lepton includes a photon beam.

First beam is lepton and second is hadron.

First beam is hadron and second is lepton.

Hadron beams gives quarks.

Case with f fbar' generic incoming state.

If beams are leptons then also colliding partons unless lepton includes a photon beam.

Hadron beams gives quarks.

Case with f fbar incoming state.

If beams are antiparticle pair and leptons then also colliding partons unless lepton includes a photon beam.

Else assume both to be hadrons, for better or worse.

Case with f fbar' charged(+-1) incoming state.

If beams are leptons then also colliding partons unless lepton includes a photon beam.

Hadron beams gives quarks.

Case with f gamma incoming state.

Fermion from incoming side A if no photon beam inside.

Fermion from incoming side B if no photon beam inside.

Photons in the beams.

Case with quark gamma incoming state.

Initialize initiators both ways if not photoproductions.

Photons in the beams.

Case with gamma quark incoming state. Need this when both resolved and unresolved photon beams.

Photon in the beam.

Case with gluon gamma incoming state.

If not photoproduction, initialize both ways. Otherwise keep track of initiator ordering to generate correct combinations (direct, resolved).

Case with gamma gluon incoming state. Need this when both resolved and unresolved photon beams.

Case with gamma gamma incoming state.

Unrecognized fluxType is bad sign. Else done.

Reimplemented in SigmaLHAProcess, and Sigma0Process.

void pickInState ( int  id1in = 0,
int  id2in = 0 

Select incoming parton channel and extract parton densities (resolved).

Multiparton interactions: partons already selected.

Pick channel. Extract channel flavours and pdf's.

double Q2Ren ( ) const

Give back couplings and parton densities. Not all known for nondiffractive.

virtual void set1Kin ( double  ,
double  ,

Input and complement kinematics for resolved 2 -> 1 process. Usage: set1Kin( x1in, x2in, sHin).

Reimplemented in Sigma1Process.

virtual void set2Kin ( double  ,
double  ,
double  ,
double  ,
double  ,
double  ,
double  ,

Input and complement kinematics for resolved 2 -> 2 process. Usage: set2Kin( x1in, x2in, sHin, tHin, m3in, m4in, runBW3in, runBW4in).

Reimplemented in Sigma2Process.

virtual void set2KinMPI ( double  ,
double  ,
double  ,
double  ,
double  ,
double  ,
double  ,
bool  ,
double  ,

Ditto, but for Multiparton Interactions applications, so different input. Usage: set2KinMPI( x1in, x2in, sHin, tHin, uHin, alpSin, alpEMin, needMasses, m3in, m4in)

Reimplemented in Sigma2Process.

virtual void set3Kin ( double  ,
double  ,
double  ,
Vec4  ,
Vec4  ,
Vec4  ,
double  ,
double  ,
double  ,
double  ,
double  ,

Input and complement kinematics for resolved 2 -> 3 process. Usage: set3Kin( x1in, x2in, sHin, p3prel, p4prel, p5prel, m3in, m4in, m5in, runBW3in, runBW4in, runBW5in);

Reimplemented in Sigma3Process.

virtual bool setupForME ( )

Calculate and store all modified masses and four-vectors intended for matrix elements. Return false if failed.

Reimplemented in Sigma3Process, Sigma2Process, and Sigma1Process.

bool setupForMEin ( )

Calculate incoming modified masses and four-vectors for matrix elements.

Initially assume it will work out to set up modified kinematics.

Correct incoming c, b, mu and tau to be massive or not.

If kinematically impossible return to massless case, but set error.

Do incoming two-body kinematics for massless or massive cases.


virtual double sigmaHat ( )

Evaluate sigma for unresolved, sigmaHat(sHat) for 2 -> 1 processes, d(sigmaHat)/d(tHat) for (resolved) 2 -> 2 processes, and |M|^2 for 2 -> 3 processes. Answer in "native" units, either mb or GeV^-2.

Reimplemented in Sigma2qgm2qgm, Sigma2qgm2qg, Sigma2ggm2qqbar, Sigma2gmgm2ffbar, Sigma2fgm2Wf, Sigma2ffbar2Wgm, Sigma2qg2Wq, Sigma2qqbar2Wg, Sigma2qqbar2LEDqqbarNew, Sigma2qqbar2LEDgg, Sigma2fgm2gmZf, Sigma2ffbar2gmZgm, Sigma2qq2LEDqq, Sigma2qg2gmZq, Sigma2qg2LEDqg, Sigma3qg2qqqbarSame, Sigma2qqbar2gmZg, Sigma2gg2LEDqqbar, Sigma3qqbar2qqbargSame, Sigma2qqbar2sleptonantislepton, Sigma2ffbar2HposHneg, Sigma2gg2LEDgg, Sigma2qqbar2chargluino, Sigma3qq2qqgSame, Sigma2ffbar2WW, Sigma2ffbar2HchgH12, Sigma2gg2LEDllbar, Sigma3qg2qqqbarDiff, Sigma2ffbar2ZW, Sigma2ffbar2A3H12, Sigma2qqbar2chi0gluino, Sigma2ffbar2LEDllbar, Sigma3qqbar2qqbargDiff, Sigma2ffbar2gmZgmZ, Sigma2qg2Hchgq, Sigma2gg2LEDgammagamma, Sigma1qq2antisquark, Sigma3qq2qqgDiff, Sigma1ffbar2Hchg, Sigma2qqbar2gluinogluino, Sigma2ffbar2LEDgammagamma, Sigma2qqbar2Hglt, Sigma2ffbar2FfbarsW, Sigma2gg2gluinogluino, Sigma3qg2qgg, Sigma2ffbar2LEDUnparticlegamma, Sigma3Process, Sigma2qg2Hqlt, Sigma2ffbar2FFbarsgmZ, Sigma2qg2squarkgluino, Sigma3qqbar2ggg, Sigma2ffbar2LEDUnparticleZ, Sigma2gg2Hglt, Sigma2Process, Sigma2ffbar2ffbarsW, Sigma3gg2ggg, Sigma2gg2squarkantisquark, Sigma2qqbar2LEDUnparticleg, Sigma2qg2Hq, Sigma2qqbar2QQbar, Sigma1Process, Sigma2ffbar2ffbarsgmZ, Sigma2qqbar2QQbar3S11QQbar3S11, Sigma2qg2LEDUnparticleq, Sigma3qqbar2HQQbar, Sigma2qqbar2squarkantisquark, Sigma0Process, Sigma2gg2QQbar, Sigma2ffbar2ffbarsgm, Sigma2gg2QQbar3S11QQbar3S11, Sigma2gg2LEDUnparticleg, Sigma2qqbar2qqbarNew, Sigma1ffbar2W, Sigma3gg2HQQbar, Sigma2QCffbar2llbar, Sigma2qq2squarksquark, Sigma2qqbar2gg, Sigma2ffbar2TEVffbar, Sigma1ffbar2gmZ, Sigma3ff2HfftWW, Sigma2qq2qq, Sigma2QCqqbar2qqbar, Sigma2gg2QQbarX8g, Sigma2qg2charsquark, Sigma2qqbar2DY, Sigma2qq2QqtW, Sigma2qqbar2GravitonStarg, Sigma2qg2qg, Sigma3ff2HfftZZ, Sigma2QCqq2qq, Sigma2ffbar2HchgchgHchgchg, Sigma2ff2fftW, Sigma2qg2GravitonStarq, Sigma2gg2qqbar, Sigma2qg2chi0squark, Sigma2gg2Sg2XXj, Sigma2ffbar2HW, Sigma2qqbar2lStarlStarBar, Sigma3ff2HchgchgfftWW, Sigma2ff2fftgmZ, Sigma2gg2gg, Sigma2gg2GravitonStarg, Sigma1gg2S2XX, Sigma2qqbar2charchar, Sigma2gg2QQbar3PJ1g, Sigma2qqbar2lStarlbar, Sigma2gg2gammagamma, Sigma1ffbar2Zv, Sigma2ffbar2HZ, Sigma1ffbar2Rhorizontal, Sigma2lgm2Hchgchgl, Sigma0AB2AXB, Sigma2qqbar2LQLQbar, Sigma2ffbar2ZpH, Sigma2qqbar2charchi0, Sigma1qqbar2KKgluonStar, Sigma0AB2XX, Sigma2ffbar2gammagamma, Sigma2gg2QQbar3S11gm, Sigma2qq2qStarq, Sigma2ffbar2fGfGbar, Sigma1ffbar2Wprime, Sigma1gmgm2H, Sigma1ll2Hchgchg, Sigma2gg2LQLQbar, Sigma0AB2AX, Sigma2gg2ggamma, Sigma2gg2QQbar3S11g, Sigma1ffbar2GravitonStar, Sigma1lgm2lStar, Sigma2qqbar2qGqGbar, Sigma1gg2H, Sigma0AB2XB, Sigma1ffbar2WRight, Sigma2qqbar2Zpg2XXj, Sigma2qg2LeptoQuarkl, Sigma2qqbar2chi0chi0, Sigma1ffbar2gmZZprime, Sigma2qqbar2ggamma, Sigma0AB2AB, Sigma2gg2qGqGbar, Sigma1ffbar2Zp2XX, Sigma1gg2GravitonStar, Sigma1ffbar2H, Sigma1qg2qStar, Sigma1ql2LeptoQuark, Sigma1ffbar2ZRight, Sigma2qg2qgamma, and Sigma0nonDiffractive.

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

Wrapper to sigmaHat, to (a) store current incoming flavours and (b) convert from GeV^-2 to mb where required. For 2 -> 1/2 also (c) convert from from |M|^2 to d(sigmaHat)/d(tHat).

Reimplemented in Sigma2Process, and Sigma1Process.

double sigmaPDF ( bool  initPS = false,
bool  samexGamma = false,
bool  useNewXvalues = false,
double  x1New = 0.,
double  x2New = 0. 

Convolute above with parton flux and K factor. Sum over open channels. Possibly different PDF in initialization phase or no sampling for x_gamma (photons in leptons).

Convolute matrix-element expression(s) with parton flux and K factor. Possibly different PDFs for the phase-space initialization. Can also take new values for x's to correct for oversampling, as needed with external photon flux.

Evaluate and store the required parton densities.

Save the x_gamma values after PDFs are called if new value is sampled if using internal photon flux from leptons.

Loop over allowed incoming channels.

Evaluate hard-scattering cross section. Include K factor.

Multiply by respective parton densities.

Sum for all channels.


Reimplemented in SigmaLHAProcess, and Sigma0Process.

virtual double weightDecay ( Event ,
int  ,
double weightHiggsDecay ( Event process,
int  iResBeg,
int  iResEnd 

Evaluate weight for Z0/W+- decay distributions in H -> Z0/W+ Z0/W- -> 4f and H -> gamma Z0 -> gamma f fbar.

If not pair Z0 Z0, W+ W- or gamma Z0 then return unit weight.

If mother is not Higgs then return unit weight.

H -> gamma Z0 -> gamma f fbar is 1 + cos^2(theta) in Z rest frame.

Parameters depend on Higgs type: H0(H_1), H^0(H_2) or A^0(H_3).

Option with isotropic decays (also for pseudoscalar fermion couplings).

Maximum and initial weight.

Find sign-matched order of Z0/W+- decay products.

Evaluate four-vector products and find masses..

For mixed CP states need epsilon product and gauge boson masses.

Z0 Z0 decay: vector and axial couplings of two fermion pairs.

Normal CP-even decay.

CP-odd decay (normal for A0(H_3)).

Mixed CP states.

W+ W- decay.

Normal CP-even decay.

CP-odd decay (normal for A0(H_3)).

Mixed CP states.


double weightTopDecay ( Event process,
int  iResBeg,
int  iResEnd 

Common code for top and Higgs secondary decay angular weights.

Evaluate weight for W decay distribution in t -> W b -> f fbar b.

If not pair W d/s/b and mother t then return unit weight.

Find sign-matched order of W decay products.

Weight and maximum weight.


Member Data Documentation

const double COMPRELERR = 1e-10

Parameters of momentum rescaling procedure: maximally allowed relative energy error and number of iterations.

const double CONVERT2MB = 0.389380

Constants: could only be changed in the code itself.

Conversion of GeV^{-2} to mb for cross section.

The SigmaProcess class. Base class for cross sections. Constants: could be changed here if desired, but normally should not. These are of technical nature, as described for each.

Particle partonT[12]

Minimal set of saved kinematics for trial interactions when using the x-dependent matter profile of multiparton interactions.

Z0 gamma* Z0* Usage

Evaluate weight for simultaneous flavours (only gamma

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