diff --git a/Hadronization/HadronSpectrum.h b/Hadronization/HadronSpectrum.h
--- a/Hadronization/HadronSpectrum.h
+++ b/Hadronization/HadronSpectrum.h
@@ -1,649 +1,649 @@
// -*- C++ -*-
#ifndef Herwig_HadronSpectrum_H
#define Herwig_HadronSpectrum_H
//
// This is the declaration of the HadronSpectrum class.
//
#include "ThePEG/Interface/Interfaced.h"
#include "HadronSpectrum.fh"
#include <ThePEG/Persistency/PersistentOStream.h>
#include <ThePEG/Persistency/PersistentIStream.h>
#include <ThePEG/PDT/ParticleData.h>
#include "Kupco.h"
/* These last two imports don't seem to be used here, but are needed for other
classes which import this. Should tidy up at some point*/
#include <ThePEG/PDT/StandardMatchers.h>
#include <ThePEG/Repository/EventGenerator.h>
namespace Herwig {
using namespace ThePEG;
/**
* Here is the documentation of the HadronSpectrum class.
*
* @see \ref HadronSpectrumInterfaces "The interfaces"
* defined for HadronSpectrum.
*/
class HadronSpectrum: public Interfaced {
public:
/** \ingroup Hadronization
* \class HadronInfo
* \brief Class used to store all the hadron information for easy access.
* \author Philip Stephens
*
* Note that:
* - the hadrons in _table can be filled in any ordered
* w.r.t. the mass value, and flavours for different
* groups (for instance, (u,s) hadrons don't need to
* be placed after (d,s) or any other flavour), but
* all hadrons with the same flavours must be consecutive
* ( for instance you cannot alternate hadrons of type
* (d,s) with those of flavour (u,s) ).
* Furthermore, it is assumed that particle and antiparticle
* have the same weights, and therefore only one of them
* must be entered in the table: we have chosen to refer
* to the particle, defined as PDG id > 0, although if
* an anti-particle is provided in input it is automatically
* transform to its particle, simply by taking the modulus
* of its id.
*/
class HadronInfo {
public:
/**
* Constructor
* @param idin The PDG code of the hadron
* @param datain The pointer to the ParticleData object
* @param swtin The singlet/decuplet/orbital factor
* @param massin The mass of the hadron
*/
HadronInfo(long idin=0, tPDPtr datain=tPDPtr(),
double swtin=1., Energy massin=ZERO)
: id(idin), ptrData(datain), swtef(swtin), wt(1.0), overallWeight(0.0),
mass(massin)
{}
/**
* Comparision operator on mass
*/
bool operator<(const HadronInfo &x) const {
if(mass!=x.mass) return mass < x.mass;
else return id < x.id;
}
/**
* The hadrons id.
*/
long id;
/**
* pointer to ParticleData, to get the spin, etc...
*/
tPDPtr ptrData;
/**
* singlet/decuplet/orbital factor
*/
double swtef;
/**
* mixing factor
*/
double wt;
/**
* (2*J+1)*wt*swtef
*/
double overallWeight;
/**
* The hadrons mass
*/
Energy mass;
/**
* Rescale the weight for a given hadron
*/
void rescale(double x) const {
const_cast<HadronInfo*>(this)->overallWeight *= x;
}
/**
* Friend method used to print the value of a table element.
*/
friend PersistentOStream & operator<< (PersistentOStream & os,
const HadronInfo & hi ) {
os << hi.id << hi.ptrData << hi.swtef << hi.wt
<< hi.overallWeight << ounit(hi.mass,GeV);
return os;
}
/**
* debug output
*/
friend ostream & operator<< (ostream & os, const HadronInfo & hi ) {
os << std::scientific << std::showpoint
<< std::setprecision(4)
<< setw(2)
<< hi.id << '\t'
<< hi.swtef << '\t'
<< hi.wt << '\t'
<< hi.overallWeight << '\t'
<< ounit(hi.mass,GeV);
return os;
}
/**
* Friend method used to read in the value of a table element.
*/
friend PersistentIStream & operator>> (PersistentIStream & is,
HadronInfo & hi ) {
is >> hi.id >> hi.ptrData >> hi.swtef >> hi.wt
>> hi.overallWeight >> iunit(hi.mass,GeV);
return is;
}
};
public:
/**
* The helper classes
*/
//@{
/**
* The type is used to contain all the hadrons info of a given flavour.
*/
typedef set<HadronInfo> KupcoData;
//@}
/**
* The hadron table type.
*/
typedef map<pair<long,long>,KupcoData> HadronTable;
public:
/** @name Standard constructors and destructors. */
//@{
/**
* The default constructor.
*/
HadronSpectrum();
/**
* The destructor.
*/
virtual ~HadronSpectrum();
//@}
public:
/** @name Partonic content */
//@{
/**
* Return the id of the gluon
*/
virtual long gluonId() const = 0;
/**
* Return the ids of all hadronizing quarks
*/
virtual const vector<long>& hadronizingQuarks() const = 0;
/**
* The light hadronizing quarks
*/
virtual const vector<long>& lightHadronizingQuarks() const = 0;
/**
* The light hadronizing diquarks
*/
virtual const vector<long>& lightHadronizingDiquarks() const = 0;
/**
* The heavy hadronizing quarks
*/
virtual const vector<long>& heavyHadronizingQuarks() const = 0;
/**
* Return true if any of the possible three input particles contains
* the indicated heavy quark. false otherwise. In the case that
* only the first particle is specified, it can be: an (anti-)quark,
* an (anti-)diquark an (anti-)meson, an (anti-)baryon; in the other
* cases, each pointer is assumed to be either (anti-)quark or
* (anti-)diquark.
*/
virtual bool hasHeavy(long id, tcPDPtr par1, tcPDPtr par2 = PDPtr(), tcPDPtr par3 = PDPtr()) const = 0;
/**
* Return true, if any of the possible input particle pointer is an
* exotic quark, e.g. Susy quark; false otherwise.
*/
virtual bool isExotic(tcPDPtr par1, tcPDPtr par2 = PDPtr(), tcPDPtr par3 = PDPtr()) const = 0;
//@}
/**
* Access the parton weights
*/
double pwt(long pid) const {
map<long,double>::const_iterator it = _pwt.find(abs(pid));
assert( it != _pwt.end() );
return it->second;
}
/**
* Return true if the two or three particles in input can be the components
* of a hadron; false otherwise.
*/
inline bool canBeHadron(tcPDPtr par1, tcPDPtr par2 , tcPDPtr par3 = PDPtr()) const {
return (!par3 && canBeMeson(par1,par2)) || canBeBaryon(par1,par2,par3);
}
/**
* Check if can't make a diquark from the partons
*/
bool canMakeDiQuark(tcPPtr p1, tcPPtr p2) const {
long id1 = p1->id(), id2 = p2->id();
return QuarkMatcher::Check(id1) && QuarkMatcher::Check(id2) && id1*id2>0;
}
/**
* Return the particle data of the diquark (anti-diquark) made by the two
* quarks (antiquarks) par1, par2.
* @param par1 (anti-)quark data pointer
* @param par2 (anti-)quark data pointer
*/
virtual PDPtr makeDiquark(tcPDPtr par1, tcPDPtr par2) const = 0;
/**
* Method to return a pair of hadrons given the PDG codes of
* two or three constituents
* @param cluMass The mass of the cluster
* @param par1 The first constituent
* @param par2 The second constituent
* @param par3 The third constituent
*/
virtual pair<tcPDPtr,tcPDPtr> chooseHadronPair(const Energy cluMass, tcPDPtr par1,
tcPDPtr par2) const;
/**
* Select the single hadron for a cluster decay
* return null pointer if not a single hadron decay
* @param par1 1st constituent
* @param par2 2nd constituent
* @param mass Mass of the cluster
*/
- tcPDPtr chooseSingleHadron(tcPDPtr par1, tcPDPtr par2, Energy mass) const;
+ virtual tcPDPtr chooseSingleHadron(tcPDPtr par1, tcPDPtr par2, Energy mass) const;
/**
* This returns the lightest pair of hadrons given by the flavours.
*
* Given the two (or three) constituents of a cluster, it returns
* the two lightest hadrons with proper flavour numbers.
* Furthermore, the first of the two hadrons must have the constituent with
* par1, and the second must have the constituent with par2.
* \todo At the moment it does *nothing* in the case that also par3 is present.
*
* The method is implemented by calling twice lightestHadron,
* once with (par1,quarktopick->CC()) ,and once with (par2,quarktopick)
* where quarktopick is either the pointer to
* d or u quarks . In fact, the idea is that whatever the flavour of par1
* and par2, no matter if (anti-)quark or (anti-)diquark, the lightest
* pair of hadrons containing flavour par1 and par2 will have either
* flavour d or u, being the lightest quarks.
* The method returns the pair (PDPtr(),PDPtr()) if anything goes wrong.
*
* \todo The method assumes par3 == PDPtr() (otherwise we don't know how to proceed: a
* possible, trivial way would be to randomly select two of the three
* (anti-)quarks and treat them as a (anti-)diquark, reducing the problem
* to two components as treated below.
* In the normal (two components) situation, the strategy is the following:
* treat in the same way the two possibilities: (d dbar) (i=0) and
* (u ubar) (i=1) as the pair quark-antiquark necessary to form a
* pair of hadrons containing the input flavour par1 and par2; finally,
* select the one that produces the lightest pair of hadrons, compatible
* with the charge conservation constraint.
*/
tcPDPair lightestHadronPair(tcPDPtr ptr1, tcPDPtr ptr2) const;
/**
* Returns the mass of the lightest pair of hadrons with the given particles
* @param ptr1 is the first constituent
* @param ptr2 is the second constituent
*/
Energy massLightestHadronPair(tcPDPtr ptr1, tcPDPtr ptr2) const {
map<pair<long,long>,tcPDPair>::const_iterator lightest =
lightestHadrons_.find(make_pair(abs(ptr1->id()),abs(ptr2->id())));
if(lightest!=lightestHadrons_.end())
return lightest->second.first->mass()+lightest->second.second->mass();
else
return ZERO;
}
/**
* Returns the lightest hadron formed by the given particles.
*
* Given the id of two (or three) constituents of a cluster, it returns
* the lightest hadron with proper flavour numbers.
* @param ptr1 is the first constituent
* @param ptr2 is the second constituent
*/
tcPDPtr lightestHadron(tcPDPtr ptr1, tcPDPtr ptr2) const;
/**
* Return the threshold for a cluster to split into a pair of hadrons.
* This is normally the mass of the lightest hadron Pair, but can be
* higher for heavy and exotic clusters
*/
virtual Energy hadronPairThreshold(tcPDPtr par1, tcPDPtr par2) const=0;
/**
* Returns the hadrons below the constituent mass threshold formed by the given particles,
* together with their total weight
*
* Given the id of two (or three) constituents of a cluster, it returns
* the lightest hadron with proper flavour numbers.
* At the moment it does *nothing* in the case that also 'ptr3' present.
* @param threshold The theshold
* @param ptr1 is the first constituent
* @param ptr2 is the second constituent
* @param ptr3 is the third constituent
*/
vector<pair<tcPDPtr,double> > hadronsBelowThreshold(Energy threshold,
tcPDPtr ptr1, tcPDPtr ptr2) const;
/**
* Return the nominal mass of the hadron returned by lightestHadron()
* @param ptr1 is the first constituent
* @param ptr2 is the second constituent
* @param ptr3 is the third constituent
*/
Energy massLightestHadron(tcPDPtr ptr1, tcPDPtr ptr2) const {
// find entry in the table
pair<long,long> ids(abs(ptr1->id()),abs(ptr2->id()));
HadronTable::const_iterator tit=_table.find(ids);
// throw exception if flavours wrong
if(tit==_table.end()||tit->second.empty())
throw Exception() << "HadronSpectrum::massLightestHadron "
<< "failed for particle" << ptr1->id() << " "
<< ptr2->id()
<< Exception::eventerror;
// return the mass
return tit->second.begin()->mass;
}
/**
* Force baryon/meson selection
*/
virtual std::tuple<bool,bool,bool> selectBaryon(const Energy cluMass, tcPDPtr par1, tcPDPtr par2) const;
/**
* Returns the mass of the lightest pair of baryons.
* @param ptr1 is the first constituent
* @param ptr2 is the second constituent
*/
Energy massLightestBaryonPair(tcPDPtr ptr1, tcPDPtr ptr2) const;
/**
* Return the weight for the given flavour
*/
virtual double pwtQuark(const long& id) const = 0;
virtual double specialQuarkWeight(double quarkWeight, long,
const Energy, tcPDPtr, tcPDPtr) const {
return quarkWeight;
}
public:
/** @name Functions used by the persistent I/O system. */
//@{
/**
* Function used to write out object persistently.
* @param os the persistent output stream written to.
*/
void persistentOutput(PersistentOStream & os) const;
/**
* Function used to read in object persistently.
* @param is the persistent input stream read from.
* @param version the version number of the object when written.
*/
void persistentInput(PersistentIStream & is, int version);
//@}
/**
* 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.
*/
static void Init();
void setGenerator(tEGPtr generator) {
Interfaced::setGenerator(generator);
}
protected:
/** @name Standard Interfaced functions. */
//@{
/**
* Initialize this object after the setup phase before saving an
* EventGenerator to disk.
*
* The array _repwt is initialized using the interfaces to set different
* weights for different meson multiplets and the constructHadronTable()
* method called to complete the construction of the hadron tables.
*
* @throws InitException if object could not be initialized properly.
*/
virtual void doinit();
//@}
/**
* Return the id of the diquark (anti-diquark) made by the two
* quarks (antiquarks) of id specified in input (id1, id2).
* Caller must ensure that id1 and id2 are quarks.
*/
virtual long makeDiquarkID(long id1, long id2, long pspin) const = 0;
protected:
/**
* Return true if the two particles in input can be the components of a meson;
*false otherwise.
*/
bool canBeMeson(tcPDPtr par1,tcPDPtr par2) const;
/**
* Return true if the two or three particles in input can be the components
* of a baryon; false otherwise.
*/
virtual bool canBeBaryon(tcPDPtr par1, tcPDPtr par2 , tcPDPtr par3 = PDPtr()) const = 0;
/**
* A sub-function of HadronSpectrum::constructHadronTable().
* It receives the information of a prospective Hadron and inserts it
* into the hadron table construct.
* @param particle is a particle data pointer to the hadron
* @param flav1 is the first constituent of the hadron
* @param flav2 is the second constituent of the hadron
*/
void insertToHadronTable(tPDPtr &particle, int flav1, int flav2);
/**
* Construct the table of hadron data
* This is the main method to initialize the hadron data (mainly the
* weights associated to each hadron, taking into account its spin,
* eventual isoscalar-octect mixing, singlet-decuplet factor). This is
* the method that one should update when new or updated hadron data is
* available.
*
* This class implements the construction of the basic table but can be
* overridden if needed in inheriting classes.
*
* The rationale for factors used for diquarks involving different quarks can
* be can be explained by taking a prototype example that in the exact SU(2) limit,
* in which:
* \f[m_u=m_d\f]
* \f[M_p=M_n=M_\Delta\f]
* and we will have equal numbers of u and d quarks produced.
* Suppose that we weight 1 the diquarks made of the same
* quark and 1/2 those made of different quarks, the fractions
* of u and d baryons (p, n, Delta) we get are the following:
* - \f$\Delta^{++}\f$: 1 possibility only u uu with weight 1
* - \f$\Delta^- \f$: 1 possibility only d dd with weight 1
* - \f$p,\Delta^+ \f$: 2 possibilities u ud with weight 1/2
* d uu with weight 1
* - \f$n,\Delta^0 \f$: 2 possibilities d ud with weight 1/2
* u dd with weight 1
* In the latter two cases, we have to take into account the
* fact that p and n have spin 1/2 whereas Delta+ and Delta0
* have spin 3/2 therefore from phase space we get a double weight
* for Delta+ and Delta0 relative to p and n respectively.
* Therefore the relative amount of these baryons that is
* produced is the following:
* # p = # n = ( 1/2 + 1 ) * 1/3 = 1/2
* # Delta++ = # Delta- = 1 = ( 1/2 + 1) * 2/3 # Delta+ = # Delta0
* which is correct, and therefore the weight 1/2 for the
* diquarks of different types of quarks is justified (at least
* in this limit of exact SU(2) ).
*/
virtual void constructHadronTable() = 0;
/**
* The table of hadron data
*/
HadronTable _table;
/**
* The PDG codes of the constituent particles allowed
*/
vector<PDPtr> _partons;
/**
* The PDG codes of the hadrons which cannot be produced in the hadronization
*/
vector<PDPtr> _forbidden;
/**
* Access to the table of hadrons
*/
const HadronTable & table() const {
return _table;
}
/**
* Access to the list of partons
*/
const vector<PDPtr> & partons() const {
return _partons;
}
/**
* Calculates a special weight specific to a given hadron.
* @param id The PDG code of the hadron
*/
double specialWeight(long id) const {
const int pspin = id % 10;
// Only K0L and K0S have pspin == 0, should
// not get them until Decay step
assert( pspin != 0 );
// Baryon : J = 1/2 or 3/2
if(pspin%2==0)
return baryonWeight(id);
// Meson
else
return mesonWeight(id);
}
/**
* Weights for mesons
*/
virtual double mesonWeight(long id) const;
/**
* Weights for baryons
*/
virtual double baryonWeight(long id) const = 0;
/**
* This method returns the proper sign ( > 0 hadron; < 0 anti-hadron )
* for the input PDG id idHad > 0, suppose to be made by the
* two constituent particle pointers: par1 and par2 (both with proper sign).
*/
int signHadron(tcPDPtr ptr1, tcPDPtr ptr2, tcPDPtr hadron) const;
/**
* Insert a meson in the table
*/
virtual void insertMeson(HadronInfo a, int flav1, int flav2) = 0;
/**
* Insert a spin\f$\frac12\f$ baryon in the table
*/
virtual void insertOneHalf(HadronInfo a, int flav1, int flav2);
/**
* Insert a spin\f$\frac32\f$ baryon in the table
*/
virtual void insertThreeHalf(HadronInfo a, int flav1, int flav2);
/**
* Option for the selection of hadrons below the pair threshold
*/
unsigned int belowThreshold_;
/**
* The weights for the excited meson multiplets
*/
vector<vector<vector<double> > > _repwt;
/**
* Weights for quarks and diquarks.
*/
map<long,double> _pwt;
/**
* Enums so arrays can be statically allocated
*/
//@{
/**
* Defines values for array sizes. L,J,N max values for excited mesons.
*/
enum MesonMultiplets { Lmax = 3, Jmax = 4, Nmax = 4};
//@}
/**
* Caches of lightest pairs for speed
*/
//@{
/**
* Masses of lightest hadron pair
*/
map<pair<long,long>,tcPDPair> lightestHadrons_;
//@}
private:
/**
* The assignment operator is private and must never be called.
* In fact, it should not even be implemented.
*/
HadronSpectrum & operator=(const HadronSpectrum &) = delete;
};
}
#endif /* Herwig_HadronSpectrum_H */
diff --git a/Hadronization/LightClusterDecayer.cc b/Hadronization/LightClusterDecayer.cc
--- a/Hadronization/LightClusterDecayer.cc
+++ b/Hadronization/LightClusterDecayer.cc
@@ -1,392 +1,405 @@
// -*- C++ -*-
//
// LightClusterDecayer.cc is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the LightClusterDecayer class.
//
#include "LightClusterDecayer.h"
#include <ThePEG/Interface/ClassDocumentation.h>
#include <ThePEG/Interface/Parameter.h>
#include <ThePEG/Interface/Reference.h>
#include <ThePEG/Interface/Switch.h>
#include <ThePEG/Persistency/PersistentOStream.h>
#include <ThePEG/Persistency/PersistentIStream.h>
#include <ThePEG/PDT/EnumParticles.h>
#include <ThePEG/Repository/EventGenerator.h>
#include "Cluster.h"
#include "Herwig/Utilities/Kinematics.h"
#include <ThePEG/Utilities/DescribeClass.h>
using namespace Herwig;
DescribeClass<LightClusterDecayer,Interfaced>
describeLightClusterDecayer("Herwig::LightClusterDecayer","Herwig.so");
IBPtr LightClusterDecayer::clone() const {
return new_ptr(*this);
}
IBPtr LightClusterDecayer::fullclone() const {
return new_ptr(*this);
}
void LightClusterDecayer::persistentOutput(PersistentOStream & os) const {
os << _hadronSpectrum;
}
void LightClusterDecayer::persistentInput(PersistentIStream & is, int) {
is >> _hadronSpectrum;
}
void LightClusterDecayer::Init() {
static ClassDocumentation<LightClusterDecayer> documentation
("There is the class responsible for the one-hadron decay of light clusters");
static Reference<LightClusterDecayer,HadronSpectrum>
interfaceHadronSpectrum("HadronSpectrum",
"A reference to the HadronSpectrum object",
&Herwig::LightClusterDecayer::_hadronSpectrum,
false, false, true, false);
}
bool LightClusterDecayer::decay(ClusterVector & clusters, tPVector & finalhadrons) {
// Loop over all clusters, and for those that were not heavy enough
// to undergo to fission, check if they are below the threshold
// for normal two-hadron decays. If this is the case, then the cluster
// should be decayed into a single hadron: this can happen only if
// it is possible to reshuffle momenta between the cluster and
// another one; in the rare occasions in which such exchange of momenta
// is not possible (because all of the clusters are too light) then
// the event is skipped.
// Notice that, differently from what happens in Fortran Herwig,
// light (that is below the threshold for the production of the lightest
// pair of hadrons with the proper flavours) fission products, produced
// by the fission of heavy clusters in class ClusterFissioner
// have been already "decayed" into single hadron (the lightest one
// with proper flavour) by the same latter class, without requiring
// any reshuffling. Therefore the light clusters that are treated in
// this LightClusterDecayer class are produced directly
// (originally) by the class ClusterFinder.
// To preserve all of the information, the cluster partner with which
// the light cluster (that decays into a single hadron) exchanges
// momentum in the reshuffling procedure is redefined and inserted
// in the vector vecNewRedefinedCluPtr. Only at the end, when all
// light clusters have been examined, the elements this vector will be
// copied in collecCluPtr (the reason is that it is not allowed to
// modify a STL container while iterating over it. At the same time,
// this ensures that a cluster can be redefined only once, which seems
// sensible although not strictly necessary).
// Notice that the cluster reshuffling partner is normally redefined
// and inserted in the vector vecNewRedefinedCluPtr, but not always:
// in the case it is also light, then it is also decayed immediately
// into a single hadron, without redefining it (the reason being that,
// otherwise, the would-be redefined cluster could have undefined
// components).
vector<tClusterPtr> redefinedClusters;
for (ClusterVector::const_iterator it = clusters.begin();
it != clusters.end(); ++it) {
// Skip the clusters that are not available or that are
// heavy, intermediate, clusters that have undergone to fission,
if ( ! (*it)->isAvailable() || ! (*it)->isReadyToDecay() ){
continue;
}
// We need to require (at least at the moment, maybe in the future we
// could change it) that the cluster has exactly two components,
// because otherwise we don't know how to deal with the kinematics.
// If this is not the case, then send a warning because it is not suppose
// to happen, and then do nothing with (ignore) such cluster.
if ( (*it)->numComponents() != 2 ) {
generator()->logWarning( Exception("LightClusterDecayer::decay "
"***Still cluster with not exactly"
" 2 components*** ",
Exception::warning) );
continue;
}
if ( DiquarkMatcher::Check((*it)->particle(0)->dataPtr()->id()) && DiquarkMatcher::Check((*it)->particle(1)->dataPtr()->id())) {
- throw Exception() << "LightClusterDecayer::decay\n*** Diquark Cluster in LightClusterDecayer ***"
- << Exception::runerror;
+ // throw Exception() << "LightClusterDecayer::decay\n*** Diquark Cluster in LightClusterDecayer ***"
+ // << Exception::runerror;
+ continue;
}
// select the hadron for single hadron decay
tcPDPtr hadron = _hadronSpectrum->chooseSingleHadron((*it)->particle(0)->dataPtr(),
(*it)->particle(1)->dataPtr(),
(**it).mass());
// if not single decay continue
if(!hadron){
continue;
}
// We assume that the candidate reshuffling cluster partner,
// with whom the light cluster can exchange momenta,
// is chosen as the closest in space-time between the available
// clusters. Notice that an alternative, sensible approach
// could be to consider instead the "closeness" in the colour
// structure...
// Notice that nor a light cluster (which decays into a single hadron)
// neither its cluster reshuffling partner (which either has a
// redefined cluster or also decays into a single hadron) can be
// a reshuffling partner of another light cluster.
// This because we are requiring that the considered candidate cluster
// reshuffling partner has the status "isAvailable && isReadyToDecay" true;
// furthermore, the new redefined clusters are not added to the collection
// of cluster before the end of the entire reshuffling procedure, avoiding
// in this way that the redefined cluster of a cluster reshuffling partner
// is used again later. Needless to say, this is just an assumption,
// although reasonable, but nothing more than that!
// Build a multimap of available reshuffling cluster partners,
// with key given by the module of the invariant space-time distance
// w.r.t. the light cluster, so that this new collection is automatically
// ordered in increasing distance values.
// We use a multimap, rather than a map, just for precaution against not properly
// defined cluster positions which could produce all identical (null) distances.
multimap<Length,tClusterPtr> candidates;
for ( ClusterVector::iterator jt = clusters.begin();
jt != clusters.end(); ++jt ) {
+ if ( (*jt)->numComponents() != 2 )
+ continue;
+ // if (DiquarkMatcher::Check(*(*jt)->particle(0)->dataPtr())
+ // && DiquarkMatcher::Check(*(*jt)->particle(1)->dataPtr()))
+ // continue;
+ // if ( DiquarkMatcher::Check(*(*jt)->particle(0)->dataPtr())
+ // && DiquarkMatcher::Check(*(*jt)->particle(1)->dataPtr()))
+ // continue;
if ((*jt)->isAvailable() && (*jt)->isReadyToDecay() && jt != it) {
Length distance = abs (((*it)->vertex() - (*jt)->vertex()).m());
candidates.insert(pair<Length,tClusterPtr>(distance,*jt));
}
}
// Loop sequentially the multimap.
multimap<Length,tClusterPtr>::const_iterator mmapIt = candidates.begin();
bool found = false;
while (!found && mmapIt != candidates.end()) {
found = reshuffling(hadron, *it, (*mmapIt).second, redefinedClusters, finalhadrons);
if (!found) ++mmapIt;
}
if (!found) return partonicReshuffle(hadron,*it,finalhadrons);
} // end loop over collecCluPtr
// Add to collecCluPtr all of the redefined new clusters (indeed the
// pointers to them are added) contained in vecNewRedefinedCluPtr.
for (tClusterVector::const_iterator it = redefinedClusters.begin();
it != redefinedClusters.end(); ++it) {
clusters.push_back(*it);
}
return true;
}
bool LightClusterDecayer::reshuffling(const tcPDPtr pdata1,
tClusterPtr cluPtr1,
tClusterPtr cluPtr2,
tClusterVector & redefinedClusters,
tPVector & finalhadrons)
{
// don't reshuffle with beam clusters
if(cluPtr2->isBeamCluster()) return false;
+
// This method does the reshuffling of momenta between the cluster "1",
// that must decay into a single hadron (with id equal to idhad1), and
// the candidate cluster "2". It returns true if the reshuffling succeed,
// false otherwise.
PPtr ptrhad1 = pdata1->produceParticle();
if ( ! ptrhad1 ) {
generator()->logWarning( Exception("LightClusterDecayer::reshuffling"
"***Cannot create a particle with specified id***",
Exception::warning) );
return false;
}
Energy mhad1 = ptrhad1->mass();
// Let's call "3" and "4" the two constituents of the second cluster
tPPtr part3 = cluPtr2->particle(0);
tPPtr part4 = cluPtr2->particle(1);
// Check if the system of the two clusters can kinematically be replaced by
// an hadron of mass mhad1 (which is the lightest single hadron with the
// same flavour numbers as the first cluster) and the second cluster.
// If not, then try to replace the second cluster with the lightest hadron
// with the same flavour numbers; if it still fails, then give up!
Lorentz5Momentum pSystem = cluPtr1->momentum() + cluPtr2->momentum();
pSystem.rescaleMass(); // set the mass as the invariant of the quadri-vector
Energy mSystem = pSystem.mass();
Energy mclu2 = cluPtr2->mass();
bool singleHadron = false;
+ bool isDiquarkCluster = DiquarkMatcher::Check(part3->dataPtr()->id()) && DiquarkMatcher::Check(part4->dataPtr()->id());
Energy mLHP2 = _hadronSpectrum->massLightestHadronPair(part3->dataPtr(),part4->dataPtr());
- Energy mLH2 = _hadronSpectrum->massLightestHadron(part3->dataPtr(),part4->dataPtr());
+ // avoid calling massLightestHadron for Diquark clusters and only allow kinematic reshuffling
+ // for diquark clusters (no singleHadron)
+ Energy mLH2 = isDiquarkCluster ? mSystem:_hadronSpectrum->massLightestHadron(part3->dataPtr(),part4->dataPtr());
if(mSystem > mhad1 + mclu2 && mclu2 > mLHP2) { singleHadron = false; }
else if(mSystem > mhad1 + mLH2) { singleHadron = true; mclu2 = mLH2; }
else return false;
// Let's call from now on "Sys" the system of the two clusters, and
// had1 (of mass mhad1) the lightest hadron in which the first
// cluster decays, and clu2 (of mass mclu2) either the second
// cluster or the lightest hadron in which it decays (depending
// which one is kinematically allowed, see above).
// The idea behind the reshuffling is to replace the system of the
// two clusters by the system of the hadron had1 and (cluster or hadron) clu2,
// but leaving the overall system unchanged. Furthermore, the motion
// of had1 and clu2 in the Sys frame is assumed to be parallel to, respectively,
// those of the original cluster1 and cluster2 in the same Sys frame.
// Calculate the unit three-vector, in the frame "Sys" along which the
// two initial clusters move.
Lorentz5Momentum u( cluPtr1->momentum() );
u.boost( - pSystem.boostVector() ); // boost from LAB to Sys
// Calculate the momenta of had1 and clu2 in the Sys frame first,
// and then boost back in the LAB frame.
Lorentz5Momentum phad1, pclu2;
if (pSystem.m() < mhad1 + mclu2 ) {
throw Exception() << "Impossible Kinematics in LightClusterDecayer::reshuffling()"
<< Exception::eventerror;
}
Kinematics::twoBodyDecay(pSystem, mhad1, mclu2, u.vect().unit(), phad1, pclu2);
ptrhad1->set5Momentum( phad1 ); // set momentum of first hadron.
ptrhad1->setVertex(cluPtr1->vertex()); // set hadron vertex position to the
// parent cluster position.
cluPtr1->addChild(ptrhad1);
finalhadrons.push_back(ptrhad1);
cluPtr1->flagAsReshuffled();
cluPtr2->flagAsReshuffled();
if(singleHadron) {
// In the case that also the cluster reshuffling partner is light
// it is decayed into a single hadron, *without* creating the
// redefined cluster (this choice is justified in order to avoid
// clusters that could have undefined components).
PPtr ptrhad2 = _hadronSpectrum->lightestHadron(part3->dataPtr(),part4->dataPtr())
->produceParticle();
ptrhad2->set5Momentum( pclu2 );
ptrhad2->setVertex( cluPtr2->vertex() ); // set hadron vertex position to the
// parent cluster position.
cluPtr2->addChild(ptrhad2);
finalhadrons.push_back(ptrhad2);
} else {
// Create the new cluster which is the redefinitions of the cluster
// partner (cluster "2") used in the reshuffling procedure of the
// light cluster (cluster "1").
// The rationale of this is to preserve completely all of the information.
ClusterPtr cluPtr2new = ClusterPtr();
if(part3 && part4) cluPtr2new = new_ptr(Cluster(part3,part4));
cluPtr2new->set5Momentum( pclu2 );
cluPtr2new->setVertex( cluPtr2->vertex() );
cluPtr2->addChild( cluPtr2new );
redefinedClusters.push_back( cluPtr2new );
// Set consistently the momenta of the two components of the second cluster
// after the reshuffling. To do that we first calculate the momenta of the
// constituents in the initial cluster rest frame; then we boost them back
// in the lab but using this time the new cluster rest frame. Finally we store
// these information in the new cluster. Notice that we do *not* set
// consistently also the momenta of the (eventual) particles pointed by the
// two components: that's because we do not need to do so, being the momentum
// an explicit private member of the class Component (which is set equal
// to the momentum of the eventual particle pointed only in the constructor,
// but then later should not necessary be the same), and furthermore it allows
// us not to loose any information, in the sense that we can always, later on,
// to find the original momenta of the two components before the reshuffling.
Lorentz5Momentum p3 = part3->momentum(); //p3new->momentum();
p3.boost( - (cluPtr2->momentum()).boostVector() ); // from LAB to clu2 (old) frame
p3.boost( pclu2.boostVector() ); // from clu2 (new) to LAB frame
Lorentz5Momentum p4 = part4->momentum(); //p4new->momentum();
p4.boost( - (cluPtr2->momentum()).boostVector() ); // from LAB to clu2 (old) frame
p4.boost( pclu2.boostVector() ); // from clu2 (new) to LAB frame
cluPtr2new->particle(0)->set5Momentum(p3);
cluPtr2new->particle(1)->set5Momentum(p4);
} // end of if (singleHadron)
return true;
}
bool LightClusterDecayer::partonicReshuffle(const tcPDPtr had,
const PPtr cluster,
tPVector & finalhadrons) {
tPPtr meson(cluster);
if(!meson->parents().empty()) meson=meson->parents()[0];
if(!meson->parents().empty()) meson=meson->parents()[0];
// check b/c hadron decay
int ptype(abs(meson->id())%10000);
bool heavy = (ptype/1000 == 5 || ptype/1000 ==4 );
heavy |= (ptype/100 == 5 || ptype/100 ==4 );
heavy |= (ptype/10 == 5 || ptype/10 ==4 );
if(!heavy) return false;
// find the leptons
tPVector leptons;
for(unsigned int ix=0;ix<meson->children().size();++ix) {
if(!(meson->children()[ix]->dataPtr()->coloured())) {
leptons.push_back(meson->children()[ix]);
}
}
if(leptons.size()==1) {
tPPtr w=leptons[0];
leptons.pop_back();
for(unsigned int ix=0;ix<w->children().size();++ix) {
if(!w->children()[ix]->dataPtr()->coloured()) {
leptons.push_back(w->children()[ix]);
}
}
}
if(leptons.size()!=2) return false;
// get momentum of leptonic system and the its minimum possible mass
Energy mmin(ZERO);
Lorentz5Momentum pw;
for(unsigned int ix=0;ix<leptons.size();++ix) {
pw+=leptons[ix]->momentum();
mmin+=leptons[ix]->mass();
}
pw.rescaleMass();
// check we can do the reshuffling
PPtr ptrhad = had->produceParticle();
// total momentum fo the system
Lorentz5Momentum pSystem = pw + cluster->momentum();
pSystem.rescaleMass();
// normal case get additional energy by rescaling momentum in rest frame of
// system
if(pSystem.mass()>ptrhad->mass()+pw.mass()&&pw.mass()>mmin) {
// Calculate the unit three-vector, in the frame "Sys" along which the
// two initial clusters move.
Lorentz5Momentum u(cluster->momentum());
u.boost( - pSystem.boostVector() );
// Calculate the momenta of had1 and clu2 in the Sys frame first,
// and then boost back in the LAB frame.
Lorentz5Momentum phad1, pclu2;
Kinematics::twoBodyDecay(pSystem, ptrhad->mass(), pw.mass(),
u.vect().unit(), phad1, pclu2);
// set momentum of first hadron.
ptrhad->set5Momentum( phad1 );
// set hadron vertex position to the parent cluster position.
ptrhad->setLabVertex(cluster->vertex());
// add hadron
cluster->addChild(ptrhad);
finalhadrons.push_back(ptrhad);
// reshuffle the leptons
// boost the leptons to the rest frame of the system
Boost boost1(-pw.boostVector());
Boost boost2( pclu2.boostVector());
for(unsigned int ix=0;ix<leptons.size();++ix) {
leptons[ix]->deepBoost(boost1);
leptons[ix]->deepBoost(boost2);
}
return true;
}
else {
return false;
}
}