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ShowerVariables.h
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// -*- C++ -*-
#ifndef HERWIG_ShowerVariables_H
#define HERWIG_ShowerVariables_H
//
// This is the declaration of the ShowerVariables class.
//
#include "ThePEG/Interface/Interfaced.h"
#include "ShowerConfig.h"
#include "Herwig++/Utilities/GlobalParameters.h"
#include "ShowerIndex.h"
#include "ShowerVariables.fh"
namespace Herwig {
using namespace ThePEG;
/** \ingroup Shower
*
* This class is responsible for keeping all the constraint information
* on the shower evolution. In particular, it has the scale value at
* which to stop the shower. Here "scale" can be either the mass scale or the
* \f$\tilde{q}\f$ (ordering variable) scale:
* this class is also responsible for the
* conversion between these two different scale definitions.
*
* Furthermore, this class can also have a veto for emission above a certain
* \f$p_T\f$ scale, or a veto for emission below a certain \f$p_T\f$ scale,
* where \f$p_T\f$ is the "resolution" variable.
* This class has also two important switches: one for switching on/off
* the multi-scale showering; and one for switching on/off the decay
* of particles (mainly Susy ones) before showering. These two switches
* are set by default, in Herwig++, to:
* - multi-scale shower 1 (ON);
* - decay before shower 0 (OFF).
* However, if you want the same behaviour as in Fortran Herwig, then set:
* - multi-scale shower 0 (OFF);
* - decay before shower 1 (ON).
*
* In the case decay before shower is ON, the set of particles to be
* decayed before showering are contained in the initialize() method:
* you need to change this method if you want add/remove a particle.
* Finally, this class has also three parameters to set the low energy
* cutoff mass scales for respectively QCD, QED, EWK radiation.
* The class provides also set/access to the upper scale for all
* interaction types and events: it is supposed to be set, at
* initialization time, by some other class, to the center of mass
* energy of the beam-beam interaction, and used as upper scale value
* for the numerically evaluation of Sudakov form factors.
*
* Notice that:
* - to be more general, one should define an abstract class
* AbsShowerVariables, which has, exactly like the present
* ShowerVariables class, the definition of all methods,
* but only the following two, which are declared as pure virtual methods
* without implementation:
* -- virtual ... convertMassScaleToQScale() = 0;
* -- virtual ... convertQScaleToMassScale() = 0;
* because it is only here that specific choice must be made
* on which ordering variable we want to use. Then, the concrete class
* ShowerVariables inherits from AbsShowerVariables
* and provides a definition for those virtual methods.
* Therefore, if we wanted a different choice, we could define another class,
* AlternativeShowerVariables, which also inherits from
* AbsShowerVariables, but provides a different definition of those methods.
*
*
* @see ShowerIndex
*
* @see \ref ShowerVariablesInterfaces "The interfaces"
* defined for ShowerVariables.
*/
class ShowerVariables: public Interfaced {
public:
/** @name Standard constructors and destructors. */
//@{
/**
* The default constructor.
*/
inline ShowerVariables();
/**
* The copy constructor.
*/
inline ShowerVariables(const ShowerVariables &);
/**
* The destructor.
*/
virtual ~ShowerVariables();
//@}
public:
/**
* Access to the various switches
*/
//@{
/**
* Access the multi-scale showering mode switch: <em>0 (OFF), 1 (ON).</em>
* By choosing <em>0 (OFF)</em>, one gets a similar behaviour to
* Fortran Herwig, in which the showering is done in one go,
* from the starting scale to the cutoff.
* The default for Herwig++ is <em>1 (ON)</em>: multi-scale showering.
*/
inline int isMultiScaleShowerON() const;
/**
* Access the decay before shower mode switch: <em>0 (OFF), 1 (ON).</em>
* By choosing <em>1 (ON)</em>, one gets a similar behaviour like in
* the Fortran Herwig, in which some particles (mainly Susy
* particles like gluinos, squarks,...) decay before showering.
* The default for Herwig++ is <em>0 (OFF)</em>: decay and shower intermixed.
*/
inline int isDecayBeforeShowerON() const;
/**
* It returns true if the particle with the specified id
* is in the list of those that should be decayed before
* showering. This method should be invoked only when the
* decay before shower mode is <em>1 (ON)</em>.
*/
inline bool hasToDecayBeforeShower(const long id) const;
/**
* It returns the low energy cutoff <em>mass </em> scale for the
* interaction type specified in input.
*/
Energy cutoffMassScale(const ShowerIndex::InteractionType interaction) const;
/**
* It returns the low energy cutoff \f$\tilde{q}\f$ scale for the
* interaction type specified in input.
*/
Energy cutoffQScale(const ShowerIndex::InteractionType interaction) const;
/**
* Specifies a kinematic cutoff used in the parton shower phase space.
*/
inline Energy kinScale() const;
//@}
/**
* It resets all the scales, and vetos.
*/
void reset();
/**
* Conversion begtween the scales.
*/
//@{
/**
* Conversion between <em>mass</em> and \f$\tilde{q}\f$ scale.
*/
inline Energy convertMassScaleToQScale(const Energy inputMassScale) const;
/**
* Conversion between \f$\tilde{q}\f$ and <em>mass</em> scale.
*/
inline Energy convertQScaleToMassScale(const Energy inputQScale) const;
//@}
/**
* Access/set the <em>mass</em> and \f$\tilde{q}\f$ scales
* at which to shower the showering.
*/
//@{
/**
* Get the <em>Mass</em> scale at which to stop the showering
*/
inline Energy stopShowerAtMassScale() const;
/**
* Set the <em>Mass</em> scale at which to stop the showering
* @param inputStopShowerAtMassScale scale at which to stop
*/
inline void stopShowerAtMassScale(const Energy inputStopShowerAtMassScale);
/**
* Get the \f$\tilde{q}\f$ scale at which to stop the showering
*/
inline Energy stopShowerAtQScale() const;
/**
* Set the \f$\tilde{q}\f$ scale at which to stop the showering
* @param inputStopShowerAtQScale scale at which to stop
*/
inline void stopShowerAtQScale(const Energy inputStopShowerAtQScale);
//@}
/**
* Access/set the Veto in \f$p_T\f$ (resolution) scale.
*/
//@{
/**
* Get \f$p_T\f$ scale above which to veto emissions.
*/
inline Energy vetoAbovePtScale() const;
/**
* Set \f$p_T\f$ scale above which to veto emissions.
* @param inputVetoAbovePtScale scale for the veto
*/
inline void vetoAbovePtScale(const Energy inputVetoAbovePtScale);
/**
* Get \f$p_T\f$ scale below which to veto emissions.
*/
inline Energy vetoBelowPtScale() const;
/**
* Set \f$p_T\f$ scale below which to veto emissions.
* @param inputVetoBelowPtScale scale for the veto
*/
inline void vetoBelowPtScale(const Energy inputVetoBelowPtScale);
//@}
/**
* Use to initialize some scales.
*/
static Energy HUGEMASS;
/**
* Access/set \f$p_T\f$ of hardest emission so far.
*/
//@{
/**
* Get the scale of hardest emission from the quark.
*/
inline Energy largestPtQ() const;
/**
* Set the scale of hardest emission from the quark.
* @param pt The scale
*/
inline void setLargestPtQ(const Energy pt);
/**
* Get the scale of hardest emission from the antiquark.
*/
inline Energy largestPtQbar() const;
/**
* Set the scale of hardest emission from the antiquark.
* @param pt The scale
*/
inline void setLargestPtQbar(const Energy pt);
//@}
/**
* Switches for matrix element corrections
*/
//@{
/**
* Any ME correction?
*/
inline bool MECOn() const;
/**
* Any hard ME correction?
*/
inline bool hardMEC() const;
/**
* Any soft ME correction?
*/
inline bool softMEC() const;
/**
* Assign asymmetric initial condition to parton shower, random or
* not? If not random, then quark gets larger initial scale.
*/
inline bool asyPS() const;
/**
* Asymmetric parton shower phase space, random choice for jet with
* large initial scale?
*/
inline bool rndPS() const;
//@}
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();
protected:
/** @name Clone Methods. */
//@{
/**
* Make a simple clone of this object.
* @return a pointer to the new object.
*/
inline virtual IBPtr clone() const;
/** Make a clone of this object, possibly modifying the cloned object
* to make it sane.
* @return a pointer to the new object.
*/
inline virtual IBPtr fullclone() const;
//@}
protected:
/** @name Standard Interfaced functions. */
//@{
/**
* Check sanity of the object during the setup phase.
*/
inline virtual void doupdate() throw(UpdateException);
/**
* Initialize this object after the setup phase before saving an
* EventGenerator to disk.
* @throws InitException if object could not be initialized properly.
*/
inline virtual void doinit() throw(InitException);
/**
* Initialize this object. Called in the run phase just before
* a run begins.
*/
inline virtual void doinitrun();
/**
* Finalize this object. Called in the run phase just after a
* run has ended. Used eg. to write out statistics.
*/
inline virtual void dofinish();
/**
* Rebind pointer to other Interfaced objects. Called in the setup phase
* after all objects used in an EventGenerator has been cloned so that
* the pointers will refer to the cloned objects afterwards.
* @param trans a TranslationMap relating the original objects to
* their respective clones.
* @throws RebindException if no cloned object was found for a given
* pointer.
*/
inline virtual void rebind(const TranslationMap & trans)
throw(RebindException);
/**
* Return a vector of all pointers to Interfaced objects used in this
* object.
* @return a vector of pointers.
*/
inline virtual IVector getReferences();
//@}
private:
/**
* Build the set of particles which should decay before shower
* (only when the decay before shower mode is 1 (ON) )
*/
void initialize();
private:
/**
* The static object used to initialize the description of this class.
* Indicates that this is a concrete class with persistent data.
*/
static ClassDescription<ShowerVariables> initShowerVariables;
/**
* The assignment operator is private and must never be called.
* In fact, it should not even be implemented.
*/
ShowerVariables & operator=(const ShowerVariables &);
private:
/**
* The switch for on/off multi-scale shower
*/
int _multiScaleShowerMode;
/**
* The switch for on/off decay before shower
*/
int _decayBeforeShowerMode;
/**
* Low-energy cutoff mass scale for QCD radiation
*/
Energy _cutoffQCDMassScale;
/**
* Low-energy cutoff mass scale for QED radiation
*/
Energy _cutoffQEDMassScale;
/**
* Low-energy cutoff mass scale for EWK radiation
*/
Energy _cutoffEWKMassScale;
/**
* Kinematic cutoff used in the parton shower phase space.
*/
Energy _kinCutoffScale;
/**
* Matrix element correction switch
*/
int _meCorrMode;
/**
* Initial conditions for the shower
*/
int _qqgPSMode;
/**
* Mass cut-off for the shower
*/
Energy _stopShowerAtMassScale;
/**
* Veto emissions above this \f$p_T\f$ scale.
*/
Energy _vetoAbovePtScale;
/**
* Veto emissions below this \f$p_T\f$ scale.
*/
Energy _vetoBelowPtScale;
/**
* \f$p_T\f$ scale of the hardest emission from the quark
*/
Energy _largestPtQ;
/**
* \f$p_T\f$ scale of the hardest emission from the antiquark
*/
Energy _largestPtQbar;
/**
* PDG codes of the particles which decay before showering
*/
set<long> _particlesDecayBeforeShower;
};
}
#include "ThePEG/Utilities/ClassTraits.h"
namespace ThePEG {
/** @cond TRAITSPECIALIZATIONS */
/** This template specialization informs ThePEG about the
* base classes of ShowerVariables. */
template <>
struct BaseClassTrait<Herwig::ShowerVariables,1> {
/** Typedef of the first base class of ShowerVariables. */
typedef Interfaced NthBase;
};
/** This template specialization informs ThePEG about the name of
* the ShowerVariables class and the shared object where it is defined. */
template <>
struct ClassTraits<Herwig::ShowerVariables>
: public ClassTraitsBase<Herwig::ShowerVariables> {
/** Return a platform-independent class name */
static string className() { return "Herwig++::ShowerVariables"; }
/** Return the name(s) of the shared library (or libraries) be loaded to get
* access to the ShowerVariables class and any other class on which it depends
* (except the base class). */
static string library() { return "HwShower.so"; }
};
/** @endcond */
}
#include "ShowerVariables.icc"
#ifndef ThePEG_TEMPLATES_IN_CC_FILE
// #include "ShowerVariables.tcc"
#endif
#endif /* HERWIG_ShowerVariables_H */

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