Belle2::EvtEtaPrimeDalitz Class Reference

Class for the simulation of the eta' -> pi+ pi- eta and pi0 pi0 eta decays. More...

#include <EvtEtaPrimeDalitz.h>

Inheritance diagram for Belle2::EvtEtaPrimeDalitz:

Collaboration diagram for Belle2::EvtEtaPrimeDalitz:

Public Member Functions
	EvtEtaPrimeDalitz ()
	Default constructor. More...
virtual	~EvtEtaPrimeDalitz ()
	Default destructor. More...
std::string	getName ()
	Returns the model name: ETAPRIME_DALITZ. More...
EvtDecayBase *	clone ()
	Returns a copy of the class object. More...
void	init ()
	Checks that the number of input parameters are correct: More...
void	initProbMax ()
	Sets the Maximum probability for the PHSP reweight. More...
void	decay (EvtParticle *p)
	Function that implements the energy-dependent Dalitz. More...

Detailed Description

Class for the simulation of the eta' -> pi+ pi- eta and pi0 pi0 eta decays.

Please not that the order of the daugther particles matters! The eta must be the last one.

Evolution of the former EvtEtaDalitz, that implements a simpler Dalitz description with hard-coded parameters. The general structure of the class, as well as several methods, are inherited from it.

The chosen pametrization is based on a power expansion of the decay amplitude squared with real cefficients (see PDG 2015):

|M|^2 = 1 + a*Y + b*Y^2 + c*X + d*X^2,

where the kinematic variable X and Y are both linear combinations of the pions' and eta kinetic energies in the eta' frame.

The model takes 4 parameters corresponing to the six coeafficients a,b,c,d; c!=0 is indication of CP violation in eta decay, and it is therefore usually set to 0. An implementation of the model with the parameters measure by BESIII collab, Phys.Rev. D92 (2015) 012014 is:

ETAPRIME_DALITZ -0.047 -0.069 0.0 0.073;

The same coeafficients are used for eta' -> eta pi0 pi0

Definition at line 48 of file EvtEtaPrimeDalitz.h.

Constructor & Destructor Documentation

EvtEtaPrimeDalitz()

Belle2::EvtEtaPrimeDalitz::EvtEtaPrimeDalitz ( )

inline

Default constructor.

Definition at line 53 of file EvtEtaPrimeDalitz.h.

{}

~EvtEtaPrimeDalitz()

virtual Belle2::EvtEtaPrimeDalitz::~EvtEtaPrimeDalitz ( )

virtual

Default destructor.

Member Function Documentation

clone()

EvtDecayBase* Belle2::EvtEtaPrimeDalitz::clone

(

)

Returns a copy of the class object.

decay()

void Belle2::EvtEtaPrimeDalitz::decay

(

EvtParticle *

p

)

Function that implements the energy-dependent Dalitz.

getName()

std::string Belle2::EvtEtaPrimeDalitz::getName

(

)

Returns the model name: ETAPRIME_DALITZ.

init()

void Belle2::EvtEtaPrimeDalitz::init

(

)

Checks that the number of input parameters are correct:

• 3 scalar particles (check on spin but not on charge)
• 4 real parameters (no check on the actual values)

initProbMax()

void Belle2::EvtEtaPrimeDalitz::initProbMax

(

)

Sets the Maximum probability for the PHSP reweight.

Maximum value is hardcoded and inherited from the EvtEtaDalitz class.

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

• EvtEtaPrimeDalitz.h