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

#include <VinciaAntennaFunctions.h>

Public Member Functions

 MECs ()
 Constructor.
 
virtual ~MECs ()
 Destructor.
 
void initPtr (Info *infoPtrIn, ShowerMEs *mg5mesPtrIn, VinciaCommon *vinComPtrIn)
 Initialize pointers. More...
 
void initAntPtr (AntennaSetFSR *antFSRusr, AntennaSetISR *antISRusr)
 Initialize pointers to antenna sets.
 
void init ()
 Initialize. More...
 
bool prepare (const int iSys, Event &event)
 Function to return ME class (Born type) for a parton configuration. More...
 
bool polarise (const int iSys, Event &event)
 Function to assign helicities to particles (using MEs). More...
 
vector< ParticlemakeParticleList (const int iSys, const Event &event, const vector< Particle > pNew=vector< Particle >(), const vector< int > iOld=vector< int >())
 Make list of particles as vector<Particle>. More...
 
bool isPolarised (int iSys, Event &event, bool checkIncoming)
 Check if state already has helicities. More...
 
AntennaFunctiongetAntFSR (const int iAnt)
 Wrapper function to return a specific antenna function.
 
AntennaFunctionIXgetAntISR (const int iAnt)
 
bool doMEC (const int iSys, const int nBranch)
 Function to determine if MECs are requested at this order for this system. More...
 
double getME2 (const vector< Particle > parts, const int nIn)
 Get squared matrix element.
 
double getME2 (const int iSys, const Event &event)
 
double getMEC (const int, const Event &)
 Get matrix element correction factor (TODO: dummy implementation).
 
int sizeOutBorn (const int iSys)
 Return number of partons added since Born (as defined by prepare).
 
void setVerbose (const int verboseIn)
 Function to set level of verbose output.
 
void header ()
 Header. More...
 

Detailed Description

Class MECs, for computing matrix-element corrections to antenna functions.

Member Function Documentation

bool doMEC ( const int  iSys,
const int  nBranch 
)

Function to determine if MECs are requested at this order for this system.

MECs in resonance decays.

MECs in Scattering Processes.

Hard processes.

MPI.

If nobody said yes by now, return the sad news.

void header ( )

Header.

Print header information.

Front matter.

Setings.

Print MG5MEs reference.

void init ( )

Initialize.

MEC settings.

Initialise MG5 interface

void initPtr ( Info infoPtrIn,
ShowerMEs mg5mesPtrIn,
VinciaCommon vinComPtrIn 
)

Initialize pointers.

Class MECs, for computing matrix-element corrections to antenna functions.

bool isPolarised ( int  iSys,
Event event,
bool  checkIncoming 
)

Check if state already has helicities.

Check if state already has helicities. Return true if any particle in state already has a specified helicity.

vector< Particle > makeParticleList ( const int  iSys,
const Event event,
const vector< Particle pNew = vector<Particle>(),
const vector< int >  iOld = vector<int>() 
)

Make list of particles as vector<Particle>.

Make list of particles as vector<Particle>. First 1 or 2 entries : incoming particle(s). Subseqent entries : outgoing particles. The two last arguments are optional and allow to specify a list of indices to be ignored, and a set of particles to be added, e.g. in the context of setting up a trial state after a branching. The newly added particles are then at the end of the respective lists, i.e. a newly added incoming particle is the last incoming one and newly added outgoing ones are the last among the outgoing ones.

Put incoming ones (initial-state partons or decaying resonance) first.

Exclude any partons in old state that should be replaced.

Exclude any partons in old state that should be replaced.

Add any post-branching incoming particles.

Sanity check; must have at least 1 incoming particle.

Then put outgoing ones.

Do not add any that are marked as branched.

Add any post-branching outgoing partons.

Return the state.

bool polarise ( const int  iSys,
Event event 
)

Function to assign helicities to particles (using MEs).

First check if we should be doing anything at all.

Hard System.

Hardest MPI system

Further MPI systems just use unpolarised showers.

Resonance-Decay systems

If state does not already have one or more assigned helicities, check if we can polarise it.

Extract particles to use for ME evaluations (incoming first)/

Verbose output.

Check if MG5MEs interface can do this.

Update particles in event record: incoming.

Update particles in event record: outgoing.

Verbose output (showing polarisations).

All is well: return true if any particles remain with assigned helicities.

bool prepare ( const int  iSys,
Event event 
)

Function to return ME class (Born type) for a parton configuration.

Function to return ME class (Born type) for a parton configuration. Can be called from either of the ISR::prepare() or FSR::prepare() functions, or from the ISR::branch() or FSR::branch() functions. Returns >= 0 if there an ME for this configuration, associated with the (arbitrary) integer code label denoted by the return value. If return < 0 we don't have an ME / no ME should be used for this system.

Initialise for no MECs, then check if MECs should be applied.

Check if MECs are switched on for this type of Born system.

Make vectors of ID codes.

Check whether MG5MEs interface has the process.


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