PYTHIA
8.312
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Helicity matrix element for a tau decay into four pions. More...
#include <HelicityMatrixElements.h>
Public Member Functions | |
void | initConstants () |
Initialize constants for the helicity matrix element. More... | |
void | initHadronicCurrent (vector< HelicityParticle > &p) |
Initialize the hadronic current for the helicity matrix element. More... | |
Public Member Functions inherited from HMETauDecay | |
virtual void | initWaves (vector< HelicityParticle > &) |
Initialize wave functions for the helicity matrix element. More... | |
virtual complex | calculateME (vector< int >) |
Return element for the helicity matrix element. | |
virtual double | decayWeightMax (vector< HelicityParticle > &) |
Return the maximum decay weight for the helicity matrix element. More... | |
Public Member Functions inherited from HelicityMatrixElement | |
HelicityMatrixElement () | |
Constructor and destructor. | |
virtual void | initPointers (ParticleData *, CoupSM *, Settings *=0) |
Initialize the physics matrices and pointers. More... | |
virtual HelicityMatrixElement * | initChannel (vector< HelicityParticle > &) |
Initialize the channel. More... | |
virtual double | decayWeight (vector< HelicityParticle > &) |
Calculate the matrix element weight for a decay. More... | |
virtual void | calculateD (vector< HelicityParticle > &) |
Calculate the decay matrix for a particle. More... | |
virtual void | calculateRho (unsigned int, vector< HelicityParticle > &) |
Calculate the density matrix for a particle. More... | |
void | setFermionLine (int, HelicityParticle &, HelicityParticle &) |
Set a fermion line. More... | |
virtual complex | breitWigner (double s, double M, double G) |
Calculate Breit-Wigner's with running widths and fixed. More... | |
virtual complex | sBreitWigner (double m0, double m1, double s, double M, double G) |
Return an s-wave BreitWigner. | |
virtual complex | pBreitWigner (double m0, double m1, double s, double M, double G) |
Return a p-wave BreitWigner. | |
virtual complex | dBreitWigner (double m0, double m1, double s, double M, double G) |
Return a d-wave BreitWigner. | |
Additional Inherited Members | |
Protected Member Functions inherited from HMETauDecay | |
virtual void | calculateResonanceWeights (vector< double > &, vector< double > &, vector< complex > &) |
Calculate complex resonance weights given a phase and amplitude vector. | |
Protected Attributes inherited from HelicityMatrixElement | |
double | DECAYWEIGHTMAX |
Maximum decay weight. WARNING: hardcoded constant. | |
vector< GammaMatrix > | gamma |
Physics matrices. | |
vector< int > | pMap |
Particle map vector. | |
vector< int > | pID |
Particle ID vector. | |
vector< double > | pM |
Particle mass vector. | |
vector< vector< Wave4 > > | u |
Wave functions. | |
ParticleData * | particleDataPtr |
Pointer to particle data. | |
CoupSM * | coupSMPtr |
Pointer to Standard Model constants. | |
Settings * | settingsPtr |
Pointer to Settings. | |
Helicity matrix element for a tau decay into four pions.
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virtual |
Initialize constants for the helicity matrix element.
Tau decay matrix element for tau decay into pions using the Novosibirsk model of Comp. Phys. Com. 174 (2006) 818-835. G(i,s): G-factor for index 1, 2, or 3 tX(q,q1,q2,q3,q4): combined resonance current a1D(s): a1 Breit-Wigner denominator rhoD(s): rho Breit-Wigner denominator sigD(s): sigma Breit-Wigner denominator omeD(s): omega Breit-Wigner denominator a1FormFactor(s): form factor for the a1 resonance rhoFormFactor1(2)(s): form factor for the rho resonance omeFormFactor(s): form factor for the omega resonance sigM: on-shell mass of the sigma resonance sigG: width of the sigma resonance sigA: amplitude of the sigma resonance sigP: phase of the sigma resonance sigW: weight of the sigma resonance (from amplitude and weight) omeX: mass, width, amplitude, phase, and weight of the omega resonance a1X: mass and width of the a1 resonance rhoX: mass and width of the rho resonance picM: charge pion mass pinM: neutral pion mass lambda2: a1 form factor cut-off
Reimplemented from HelicityMatrixElement.
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virtual |
Initialize the hadronic current for the helicity matrix element.
Create pion momenta.
Calculate the four pion system energy.
Create the hadronic current for the 3 neutral pion channel.
Create the hadronic current for the 3 charged pion channel.
Reimplemented from HMETauDecay.