Herwig++
2.7.0
|
Here is the documentation of the MEPP2VVPowheg class. More...
#include <MEPP2VVPowheg.h>
Public Member Functions | |
MEPP2VVPowheg () | |
The default constructor. | |
virtual bool | generateKinematics (const double *r) |
Generate internal degrees of freedom given nDim() uniform random numbers in the interval ![]() | |
virtual int | nDim () const |
The number of internal degrees of freedom used in the matrix element. | |
virtual double | me2 () const |
The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number. | |
virtual Energy2 | scale () const |
Return the scale associated with the last set phase space point. | |
bool | sanityCheck () const |
This member check the collinear limits of the real emission matrix elements are equal to the appropriate combinations of Born ME's multiplied by the splitting functions. | |
Complex | CKM (int ix, int iy) const |
Return the CKM matrix elements. | |
void | getKinematics (double xt, double y, double theta2) |
Function to set the born variables. | |
double | NLOweight () const |
Calculate the correction weight with which leading-order configurations are re-weighted. | |
double | Lhat_ab (tcPDPtr a, tcPDPtr b, realVVKinematics Kinematics) const |
Calculate the ratio of the NLO luminosity to the LO luminosity function for the ![]() | |
double | Vtilde_universal (realVVKinematics S) const |
Calculate the universal soft-virtual contribution to the NLO weight. | |
double | Ctilde_Ltilde_qq_on_x (tcPDPtr a, tcPDPtr b, realVVKinematics C) const |
Function for calculation of the ![]() | |
double | Ctilde_Ltilde_gq_on_x (tcPDPtr a, tcPDPtr b, realVVKinematics C) const |
Function for calculation of the ![]() | |
double | Rtilde_Ltilde_qqb_on_x (tcPDPtr a, tcPDPtr b) const |
Function for calculation of the ![]() | |
double | Rtilde_Ltilde_qg_on_x (tcPDPtr a, tcPDPtr b) const |
Function for calculation of the ![]() | |
double | Rtilde_Ltilde_gqb_on_x (tcPDPtr a, tcPDPtr b) const |
Function for calculation of the ![]() | |
double | M_V_regular (realVVKinematics S) const |
The regular part of the virtual correction matrix element(s). | |
Energy2 | t_u_M_R_qqb (realVVKinematics R) const |
The matrix element q + qb -> n + g times tk*uk. | |
Energy2 | t_u_M_R_qg (realVVKinematics R) const |
The matrix element q + g -> n + q times tk*uk. | |
Energy2 | t_u_M_R_gqb (realVVKinematics R) const |
The matrix element g + qb -> n + q times tk*uk. | |
Energy2 | t_u_M_R_qqb_hel_amp (realVVKinematics R) const |
The matrix element q + qb -> n + g times (tk*uk)^2 - using helicity amplitudes. | |
Energy2 | t_u_M_R_qg_hel_amp (realVVKinematics R) const |
The matrix element q + g -> n + q times (tk*uk)^2 - using helicity amplitudes. | |
Energy2 | t_u_M_R_gqb_hel_amp (realVVKinematics R) const |
The matrix element g + qb -> n + qb times (tk*uk)^2 - using helicity amplitudes. | |
double | lo_me () const |
The leading order matrix element - using helicity amplitudes. | |
double | M_Born_WZ (bornVVKinematics B) const |
The Born matrix element as given in Equation 3.1 - 3.3 in NPB 383 (1992) *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element. | |
double | M_Born_ZZ (bornVVKinematics B) const |
The Born matrix element as given in Equation 2.18 - 2.19 in NPB 357 (1991) *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element. | |
double | M_V_regular_ZZ (realVVKinematics S) const |
M_V_regular_ZZ is the regular part of the one-loop ZZ matrix element exactly as defined in Eqs. | |
Energy2 | t_u_M_R_qqb_ZZ (realVVKinematics R) const |
t_u_M_R_qqb_ZZ is the q + qb -> n + g times tk*uk real emission matrix element as defined in Eq. | |
double | M_Born_WW (bornVVKinematics B) const |
The Born matrix element as given in Equation 3.2 - 3.8 in NPB 410 (1993) *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element. | |
double | M_V_regular_WW (realVVKinematics S) const |
M_V_regular_WW is the regular part of the one-loop WW matrix element exactly as defined in Eqs. | |
Energy2 | t_u_M_R_qqb_WW (realVVKinematics R) const |
t_u_M_R_qqb_WW is the q + qb -> n + g times tk*uk real emission matrix element as defined in Eq. | |
Energy2 | mu_F2 () const |
Return the factorion scale squared. | |
Energy2 | mu_UV2 () const |
Return the renormalisation scale squared. | |
Member functions for the generation of hard QCD radiation | |
virtual POWHEGType | hasPOWHEGCorrection () |
Has a POWHEG style correction. | |
virtual HardTreePtr | generateHardest (ShowerTreePtr) |
Apply the POWHEG style correction. | |
Functions used by the persistent I/O system. | |
void | persistentOutput (PersistentOStream &os) const |
Function used to write out object persistently. | |
void | persistentInput (PersistentIStream &is, int version) |
Function used to read in object persistently. | |
Static Public Member Functions | |
static void | Init () |
The standard Init function used to initialize the interfaces. | |
Public Attributes | |
double | M_V_regular_ |
Member variable to store the regular part of the virtual correction matrix element(s). | |
Energy2 | t_u_M_R_qqb_ |
Member variable to store the matrix element q + qb -> n + g times tk*uk. | |
Energy2 | t_u_M_R_qg_ |
Member variable to store the matrix element q + g -> n + q times tk*uk. | |
Energy2 | t_u_M_R_gqb_ |
Member variable to store the matrix element g + qb -> n + q times tk*uk. | |
Energy2 | t_u_M_R_qqb_hel_amp_ |
Member variable to store the matrix element q + qb -> n + g times (tk*uk)^2 - using helicity amplitudes. | |
Energy2 | t_u_M_R_qg_hel_amp_ |
Member variable to store the matrix element q + g -> n + q times (tk*uk)^2 - using helicity amplitudes. | |
Energy2 | t_u_M_R_gqb_hel_amp_ |
Member variable to store the matrix element g + qb -> n + qb times (tk*uk)^2 - using helicity amplitudes. | |
double | M_Born_ |
Member variable to store the Born matrix element as given in Equation 3.1 - 3.3 in NPB 383 (1992) *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element. | |
Protected Member Functions | |
double | getResult (int emis_type, realVVKinematics R, Energy pT) |
Returns the matrix element for a given type of process, rapidity of the jet ![]() ![]() | |
bool | getEvent (vector< Lorentz5Momentum > &pnew, unsigned int &emissiontype) |
generates the hardest emission (yj,p) | |
void | setTheScales (Energy pT) |
sets the QCD, EW and PDF scales | |
Energy2 | t_u_M_R_qqb_hel_amp (realVVKinematics R, bool getMatrix) const |
The matrix element q + qb -> n + g times tk*uk. | |
Energy2 | t_u_M_R_qg_hel_amp (realVVKinematics R, bool getMatrix) const |
The matrix element q + g -> n + q times tk*uk. | |
Energy2 | t_u_M_R_gqb_hel_amp (realVVKinematics R, bool getMatrix) const |
The matrix element g + qb -> n + q times tk*uk. | |
double | lo_me (bool getMatrix) const |
The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number. | |
void | recalculateVertex () |
Recalculate hard vertex to include spin correlations for radiative events. | |
bool | isotropicDecayer () |
Member which selects a two body decay mode for each vector boson and distributes decay products isotropically. | |
Energy2 | triangleFn (Energy2, Energy2, Energy2) |
The triangle function lambda(x,y,z)=sqrt(x^2+y^2+z^2-2*x*y-2*y*z-2*x*z) | |
Standard Interfaced functions. | |
virtual void | doinit () |
Initialize this object after the setup phase before saving an EventGenerator to disk. | |
Clone Methods. | |
virtual IBPtr | clone () const |
Make a simple clone of this object. | |
virtual IBPtr | fullclone () const |
Make a clone of this object, possibly modifying the cloned object to make it sane. | |
Private Member Functions | |
MEPP2VVPowheg & | operator= (const MEPP2VVPowheg &) |
The assignment operator is private and must never be called. | |
Private Attributes | |
double | alphaS_ |
The value of ![]() | |
bool | realMESpinCorrelations_ |
If this boolean is true the n+1 body helicity amplitudes will be used to calculate a hard vertex based on those kinematics for spin correlations in the decays. | |
double | lo_me_ |
The colour & spin averaged n-body (leading order) matrix element squared. | |
realVVKinematics | R_ |
The resolved 2->3 real emission kinematics. | |
unsigned int | channel_ |
This specifies the emitting configuration: 1: q + qbar -> V1 + V2 + g 2: q + g -> V1 + V2 + q 3: g + qbar -> V1 + V2 + qbar. | |
int | fermionNumberOfMother_ |
Identifies the space-like mother of the branching as quark (+1) or antiquark (-1): | |
ShowerAlphaPtr | showerAlphaS_ |
Pointer to the object calculating the strong coupling. | |
Energy | min_pT_ |
The transverse momentum of the jet. | |
Energy2 | QCDScale_ |
Scale for alpha_S: pT^2 of the diboson system. | |
Energy2 | PDFScale_ |
Scale for real emission PDF: | |
Energy2 | EWScale_ |
Scale of electroweak vertices: mVV^2 the invariant mass of the diboson system. | |
Complex | productionMatrix_ [3][3][3][3] |
A matrix to hold the home-grown production matrix element. | |
double | tiny |
Parameters for the NLO weight. | |
tcBeamPtr | hadron_A_ |
The BeamParticleData object for the plus and minus direction hadrons. | |
tcBeamPtr | hadron_B_ |
bornVVKinematics | B_ |
Born / virtual 2->2 kinematics. | |
realVVKinematics | S_ |
Soft limit of the 2->3 real emission kinematics. | |
realVVKinematics | SCp_ |
Soft-collinear limit of the 2->3 kinematics (emission in +z direction). | |
realVVKinematics | SCm_ |
The collinear limit of the 2->3 kinematics (emission in -z direction). | |
realVVKinematics | Cp_ |
The collinear limit of the 2->3 kinematics (emission in +z direction). | |
realVVKinematics | Cm_ |
The collinear limit of the 2->3 kinematics (emission in -z direction). | |
realVVKinematics | H_ |
The resolved 2->3 real emission kinematics: | |
tcPDPtr | ab_ |
The ParticleData object for the plus and minus lo partons. | |
tcPDPtr | bb_ |
tcPDPtr | quark_ |
The ParticleData object for the quark and antiquark (which can be in a different order to ab_ and bb_). | |
tcPDPtr | antiquark_ |
double | lo_lumi_ |
Values of the PDF's before radiation. | |
double | lo_me2_ |
The value of the leading order qqbar->VV matrix element. | |
double | CF_ |
The CF_ colour factor. | |
double | TR_ |
The TR_ colour factor. | |
double | NC_ |
The number of colours. | |
double | gW_ |
The weak coupling and the sin (squared) of the Weinberg angle. | |
double | sin2ThetaW_ |
double | guL_ |
The up and down, left handed, quark-boson couplings. | |
double | gdL_ |
double | guR_ |
The up and down, right handed, quark-boson couplings (for WW & ZZ) | |
double | gdR_ |
double | eZ_ |
The TGC coupling. | |
double | eZ2_ |
The TGC coupling squared. | |
double | Fij2_ |
The CKM factor (Fij^2) | |
unsigned int | contrib_ |
Whether to generate the positive, negative or leading order contribution. | |
unsigned int | channels_ |
Whether to generate all channels contributions or just qqb or just qg+gqb contributions. | |
unsigned int | nlo_alphaS_opt_ |
Whether to use a fixed or a running QCD coupling for the NLO weight. | |
double | fixed_alphaS_ |
The value of alphaS to use for the nlo weight if nlo_alphaS_opt_=1. | |
unsigned int | removebr_ |
Flag to remove or multiply in MCFM branching fractions for testing. | |
unsigned int | scaleopt_ |
Selects a dynamic (sHat) or fixed factorization scale. | |
Energy | mu_F_ |
The factorization scale. | |
Energy | mu_UV_ |
The renormalization scale. | |
Energy2 | k1r_perp2_lab_ |
The pT of V1 in a radiative event in the lab frame (for scale setting only) | |
Energy2 | k2r_perp2_lab_ |
The pT of V2 in a radiative event in the lab frame (for scale setting only) | |
vector< vector< Complex > > | ckm_ |
The ckm matrix elements (unsquared, to allow interference) | |
bool | helicityConservation_ |
Option to impose helicity conservation on the real NLO ME's (greatly improves evaluation time). | |
ProductionMatrixElement | qqb_hel_amps_ |
The q + qb -> v1 + v2 + g helicity amplitudes. | |
ProductionMatrixElement | qg_hel_amps_ |
The q + g -> v1 + v2 + q helicity amplitudes. | |
ProductionMatrixElement | gqb_hel_amps_ |
The g + qb -> v1 + v2 + qb helicity amplitudes. | |
AbstractFFVVertexPtr | FFPvertex_ |
The vertices. | |
AbstractFFVVertexPtr | FFWvertex_ |
The W fermion-antifermion vertex. | |
AbstractFFVVertexPtr | FFZvertex_ |
The Z fermion-antifermionvertex. | |
AbstractVVVVertexPtr | WWWvertex_ |
The triple electroweak gauge boson vertex. | |
AbstractFFVVertexPtr | FFGvertex_ |
The quark-antiquark gluon vertex. | |
double | power_ |
Constants for the sampling. | |
double | preqqbar_ |
The prefactor, ![]() ![]() | |
double | preqg_ |
The prefactor, ![]() ![]() | |
double | pregqbar_ |
The prefactor, ![]() ![]() | |
double | b0_ |
The QCD beta function divided by 4pi, (11-2/3*nf)/4/pi, with nf = 5. | |
Energy | LambdaQCD_ |
The fundamental QCD scale in the one-loop alpha_{S} used for the crude (not the very crude) overestimate of the Sudakov exponent. | |
vector< double > | prefactor_ |
The prefactors as a vector for easy use. | |
ShowerProgenitorPtr | qProgenitor_ |
Properties of the incoming particles. | |
ShowerProgenitorPtr | qbProgenitor_ |
ShowerParticlePtr | showerQuark_ |
Pointers to the Shower particle objects for the partons. | |
ShowerParticlePtr | showerAntiquark_ |
tcBeamPtr | qHadron_ |
Pointers to the BeamParticleData objects. | |
tcBeamPtr | qbHadron_ |
PPtr | gluon_ |
Properties of the boson and jets. | |
ShowerParticlePtr | V1_ |
ShowerParticlePtr | V2_ |
vector< PPtr > | children_ |
vector< PPtr > | photons_ |
bool | flipped_ |
Flag indicating if the q & qbar are flipped or not i.e. | |
double | Yk_ |
the rapidity of the jet | |
Energy | pT_ |
The transverse momentum of the jet. | |
Static Private Attributes | |
static ClassDescription < MEPP2VVPowheg > | initMEPP2VVPowheg |
The static object used to initialize the description of this class. |
Here is the documentation of the MEPP2VVPowheg class.
Definition at line 25 of file MEPP2VVPowheg.h.
virtual IBPtr Herwig::MEPP2VVPowheg::clone | ( | ) | const [inline, protected, virtual] |
Make a simple clone of this object.
Reimplemented from Herwig::MEPP2VV.
Definition at line 348 of file MEPP2VVPowheg.h.
virtual void Herwig::MEPP2VVPowheg::doinit | ( | ) | [protected, virtual] |
Initialize this object after the setup phase before saving an EventGenerator to disk.
InitException | if object could not be initialized properly. |
Reimplemented from Herwig::MEPP2VV.
virtual IBPtr Herwig::MEPP2VVPowheg::fullclone | ( | ) | const [inline, protected, virtual] |
Make a clone of this object, possibly modifying the cloned object to make it sane.
Reimplemented from Herwig::MEPP2VV.
Definition at line 354 of file MEPP2VVPowheg.h.
virtual bool Herwig::MEPP2VVPowheg::generateKinematics | ( | const double * | r | ) | [virtual] |
Generate internal degrees of freedom given nDim() uniform random numbers in the interval .
To help the phase space generator, the dSigHatDR should be a smooth function of these numbers, although this is not strictly necessary.
r | a pointer to the first of nDim() consecutive random numbers. |
Reimplemented from Herwig::HwMEBase.
bool Herwig::MEPP2VVPowheg::getEvent | ( | vector< Lorentz5Momentum > & | pnew, |
unsigned int & | emissiontype | ||
) | [protected] |
generates the hardest emission (yj,p)
pnew | The momenta of the new particles |
emissiontype | The type of emission, as for getResult |
double Herwig::MEPP2VVPowheg::getResult | ( | int | emis_type, |
realVVKinematics | R, | ||
Energy | pT | ||
) | [protected] |
Returns the matrix element for a given type of process, rapidity of the jet and transverse momentum
.
emis_type | the type of emission, (0 is ![]() ![]() ![]() |
pT | The transverse momentum of the jet |
R | The object containing the kinematics |
static void Herwig::MEPP2VVPowheg::Init | ( | ) | [static] |
The standard Init function used to initialize the interfaces.
Called exactly once for each class by the class description system before the main function starts or when this class is dynamically loaded.
Reimplemented from Herwig::MEPP2VV.
double Herwig::MEPP2VVPowheg::lo_me | ( | bool | getMatrix | ) | const [protected] |
The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number.
double Herwig::MEPP2VVPowheg::M_V_regular | ( | realVVKinematics | S | ) | const |
The regular part of the virtual correction matrix element(s).
For WZ production this is given by Equation B.2 in NPB 383 (1992) 3-44 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
double Herwig::MEPP2VVPowheg::M_V_regular_WW | ( | realVVKinematics | S | ) | const |
M_V_regular_WW is the regular part of the one-loop WW matrix element exactly as defined in Eqs.
C.1 - C.7 of of NPB 410(1993)280-324 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
double Herwig::MEPP2VVPowheg::M_V_regular_ZZ | ( | realVVKinematics | S | ) | const |
M_V_regular_ZZ is the regular part of the one-loop ZZ matrix element exactly as defined in Eqs.
B.1 & B.2 of NPB 357(1991)409-438 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
virtual double Herwig::MEPP2VVPowheg::me2 | ( | ) | const [virtual] |
The matrix element for the kinematical configuration previously provided by the last call to setKinematics(), suitably scaled by sHat() to give a dimension-less number.
Reimplemented from Herwig::MEPP2VV.
MEPP2VVPowheg& Herwig::MEPP2VVPowheg::operator= | ( | const MEPP2VVPowheg & | ) | [private] |
The assignment operator is private and must never be called.
In fact, it should not even be implemented.
void Herwig::MEPP2VVPowheg::persistentInput | ( | PersistentIStream & | is, |
int | version | ||
) |
Function used to read in object persistently.
is | the persistent input stream read from. |
version | the version number of the object when written. |
Reimplemented from Herwig::MEPP2VV.
void Herwig::MEPP2VVPowheg::persistentOutput | ( | PersistentOStream & | os | ) | const |
Function used to write out object persistently.
os | the persistent output stream written to. |
Reimplemented from Herwig::MEPP2VV.
void Herwig::MEPP2VVPowheg::setTheScales | ( | Energy | pT | ) | [protected] |
sets the QCD, EW and PDF scales
pT | The pT of the current step in the veto algorithm |
Energy2 Herwig::MEPP2VVPowheg::t_u_M_R_qqb_WW | ( | realVVKinematics | R | ) | const |
t_u_M_R_qqb_WW is the q + qb -> n + g times tk*uk real emission matrix element as defined in Eq.
D.1-D.5 of NPB 410(1993)280-324 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
Energy2 Herwig::MEPP2VVPowheg::t_u_M_R_qqb_ZZ | ( | realVVKinematics | R | ) | const |
t_u_M_R_qqb_ZZ is the q + qb -> n + g times tk*uk real emission matrix element as defined in Eq.
C.1 of NPB 357(1991)409-438 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
double Herwig::MEPP2VVPowheg::eZ2_ [mutable, private] |
The TGC coupling squared.
This is useful for debugging purposes when one wants to turn of t-channel * TGC interference contributions but leave the pure TGC contributions intact. It is also needed in order to transform WZ matrix elements into WW ones.
Definition at line 487 of file MEPP2VVPowheg.h.
The vertices.
The photon fermion-antifermion vertex
Reimplemented from Herwig::MEPP2VV.
Definition at line 578 of file MEPP2VVPowheg.h.
bool Herwig::MEPP2VVPowheg::flipped_ [private] |
Flag indicating if the q & qbar are flipped or not i.e.
this is true if q enters from the -z direction in the lab frame.
Definition at line 795 of file MEPP2VVPowheg.h.
PPtr Herwig::MEPP2VVPowheg::gluon_ [private] |
Properties of the boson and jets.
Pointers to the Shower particle objects for the partons
Definition at line 785 of file MEPP2VVPowheg.h.
ClassDescription<MEPP2VVPowheg> Herwig::MEPP2VVPowheg::initMEPP2VVPowheg [static, private] |
The static object used to initialize the description of this class.
Indicates that this is a concrete class with persistent data.
Definition at line 363 of file MEPP2VVPowheg.h.
Energy Herwig::MEPP2VVPowheg::LambdaQCD_ [private] |
The fundamental QCD scale in the one-loop alpha_{S} used for the crude (not the very crude) overestimate of the Sudakov exponent.
The default value is set so such that alphaS(MZ), neglecting all flavour threshold effects i.e. MZ*exp(-1/2/b0_/alphaS(MZ)).
Definition at line 747 of file MEPP2VVPowheg.h.
double Herwig::MEPP2VVPowheg::M_V_regular_ [mutable] |
Member variable to store the regular part of the virtual correction matrix element(s).
For WZ production this is given by Equation B.2 in NPB 383 (1992) 3-44 *** modulo a factor 1/(2s) ***, which is a flux factor that those authors absorb in the matrix element.
Definition at line 199 of file MEPP2VVPowheg.h.
double Herwig::MEPP2VVPowheg::power_ [private] |
Constants for the sampling.
The distribution is assumed to have the form The power,
, for the sampling
Definition at line 719 of file MEPP2VVPowheg.h.
ShowerProgenitorPtr Herwig::MEPP2VVPowheg::qProgenitor_ [private] |
Properties of the incoming particles.
Pointers to the ShowerProgenitor objects for the partons
Definition at line 762 of file MEPP2VVPowheg.h.
double Herwig::MEPP2VVPowheg::tiny [private] |
Parameters for the NLO weight.
Parameter to determine when to use limiting value of real emission matrix elements, to avoid rounding error issues.
Definition at line 382 of file MEPP2VVPowheg.h.