File: DecayMode.h

This file may become a part of CLHEP - a Class Library for High Energy Physics.

This is the definition of the HepDecayMode class.

The HepDecayMode class defines one possible decay of a particle. It is designed to be able to handle most of the measured decay channels published by the ParticleData Group and the specification of different decay products is therefore fairly complex.

An object of the HepDecayMode class contains the following

• a const pointer to a HepParticleData object corresponding to the decaying particle.
• a measured branching ratio with errors.
• a std::multiset of const pointers to HepParticleData objects corresponding to uniquely identified decay products.
• a std::multiset of const pointers to HepDecayMode objects corresponding to a subsequent decay of a uniquely identified resonant decay product (which is then not listed in the set of HepParticleData objects above).
• a std::set of HepParticleData objects corresponding to resonances which are excluded as intermediate decay products.
• a std::multiset of const pointers to HepParticleMatcher objects, each corresponding to one decay product identified to be one of the particles matched.
• a const pointer to a HepParticleMatcher object corresponding to an arbitrary number of decay products, all identified to be among the matched particles.

Since there may be some overlap between different decay modes for a given particle, the HepDecayMode object also includes a list of other decay modes which are included as a special case of the current one.

The object also contains an std::string tag which uniquely defines the decay mode. This string is made up from the name of the decaying particle, followed by a colon, followed by a comma-separaterd list of decay products specifiers ended by a semi-colon. The tag must not contain any white-space characters. The decay mode specifiers should be given in the following order:

• The names of the uniquely identified decay products in the order of their STDHEP numbers.
• The tags of the decay modes corresponding to subsequent decays of uniquely identified resonant decay products, enclosed in square brackets and ordered lexicographically.
• The names of the HepParticleMatcher objects which each correspond to one decay product, preceeded by a '?' in lexicographical order.
• The name of the HepParticleMatcher object corresponding to an unknown number of decay products preceeded by a '*'.
• The names of the excluded intermediate resonances preceeded by a '!' in the order of their STDHEP numbers.

Finally, a HepDecayMode object contains a std::map associating HepPackageHandle numbers with pointers to HepDecayer objects paired with a branching ratio.

PDT.h PDTable.h ParticleData.h ParticleMatcher.h PackageHandler.h

Leif Lönnblad

typedef map<HepPkg, pair<HepDecayModel *, HepDouble>,
  less<HepPkg> > ModelMap;
typedef multiset<const HepParticleData *,
  less<const HepParticleData *> > ParticleSet;
typedef multiset<const HepParticleMatcher *,
  less <const HepParticleMatcher *> > MatcherSet;
typedef multiset<const HepDecayMode *,
  less<const HepDecayMode *> > ModeSet;
Convenient typedefs.

class HepDecayTable;
class HepPDTable;

inline HepDecayMode();
The constructor.

inline ~HepDecayMode();
The destructor.

inline const HepString & tag() const;
Return the tag for this decay mode.

inline const HepString & tag(const HepString &);
Return the tag for this decay mode.

inline void addProduct(const HepParticleData &);
Add identified decay products.

inline void addCascadeProduct(const HepDecayMode &);
Add identified resonant product with specified decay mode.

inline void addProductMatcher(const HepParticleMatcher &);
Add a mathcer corresponding to one decay product.

inline void setWildMatcher(const HepParticleMatcher &);
Add a matcher corresponding to any number of decay products.

inline void addExcluded(const HepParticleData &);
Add a particle corresponding to an excluded intermediate resonance.

inline void parent(const HepParticleData &);
inline const HepParticleData * parent() const;
Set/get a pointer to the particle data object corresponding to the decaying particle.

inline const ParticleSet & products() const;
The set of identified decay products.

inline const ModeSet & cascadeProducts() const;
The set of identified resonant products with specified decay modes

inline const MatcherSet & productMatchers() const;
The set of matchers each corresponding to one decay product.

inline const HepParticleMatcher * wildProductMatcher() const;
The pointer to a matcher corresponding to any number of decay products

inline const ParticleSet & excluded() const;
The set particles corresponding to excluded intermediate resonances.

inline HepDouble bRatio(HepDouble, HepDouble = 0.0,
  HepDouble = -1.0);
inline HepDouble bRatio() const;
inline HepDouble bRatioErrPos() const;
inline HepDouble bRatioErrNeg() const;
Set/return the measured branching ratio. Arguments for the set method are the branching ratio, the positive and negative error. If the negative error is left out, it is set to the positive error.

inline HepDouble bRatio(HepPkg, HepDouble);
inline HepDouble bRatio(HepPkg) const;
Set/return the bRatio branching ratio to be used for by a given package number.

inline void switchOn(HepPkg = HepPkgDefault);
inline void switchOff(HepPkg = HepPkgDefault);
Switch on/off this decay mode for a given package number.

HepBoolean includes(const HepDecayMode &) const;
Check if another decay mode is included in this one.

inline HepBoolean operator == (const HepDecayMode &) const;
Check if another decay mode has the same final state as this one.

inline const vector<const HepDecayMode *> & overlap() const;
Return the list of overlapping decay modes.

inline void addModel(HepPkg, HepDecayModel &,
  HepDouble = -1.0);
inline HepDecayModel * model(HepPkg = HepPkgDefault) const;
Add/return a pointer to an object corresponding to given package number capable of performing the decay. Optionally also set the branching ratio to be used by this package.

inline void setDefaultModel(HepPkg);
inline HepPkg defaultModel() const;
Set/get the default decay model.

HepBoolean addOverlap(const HepDecayMode &);
Add a decay mode to the list of overlapping modes if included.

inline void resetOverlap();
Remove all decay modes from the list of overlapping modes.

HepString nameTag;
The tag.

const HepParticleData * decayingParticle;
Pointer to a particle data object corresponding to the decaying particle.

HepDouble brat;
HepDouble dbratp;
HepDouble dbratn;
The measured branching fraction for this decay mode.

ParticleSet decayProducts;
The set of specified decay particles.

ModeSet cascadeDecayProducts;
The set of matching decay channels corresponding to a specified particle with a specified subsequent decay mode.

MatcherSet decayProductMatchers;
The set of matching decay products. Each of the matchers correspond to one particle.

const HepParticleMatcher * wildDecayProductMatch;
A particle matcher which corresponds to zero or more particles.

ParticleSet excludedIntermediateProducts;
A set of particles which are not allowed as intermediate resonances.

vector<const HepDecayMode *> overlappingModes;
A list of decay modes which are included in this one.

ModelMap models;
A map relating package numbers (related to package names such as "G4" or "Jetset" in HepPDTable) to a pointer to an object which is able to perform the actual decay and the exclusive branching ratio used for the package.

HepPkg defmod;
The number of the default decay model.

CLASS DECLARATIONS

class HepDecayModel

DEFINED MACROS

HepDecayMode_H_INCLUDED
inline

INCLUDED FILES

CLHEP/PDT/ParticleMatcher.h
vector
multiset.h
CLHEP/PDT/DecayMode.icc