Pmunu Class Reference

A class for \( \pi \to \lepton \nu \). More...

#include <Pmunu.h>

Inheritance diagram for Pmunu:

Detailed Description

A class for \( \pi \to \lepton \nu \).

Author

HEPfit Collaboration

Copyright

GNU General Public License

This class is used to compute the theoretical value of the width of \( \pi \to \lepton \nu \).

Definition at line 30 of file Pmunu.h.

Public Member Functions
double	computeThValue ()
	arXiv:1605.07114 More...
	Pmunu (const StandardModel &SM_i)
	Constructor. More...
Public Member Functions inherited from ThObservable
double	getBinMax ()
	A get method to get the maximum value of the bin. More...
double	getBinMin ()
	A get method to get the minimum value of the bin. More...
const StandardModel &	getModel ()
	A get method to get the model. More...
const std::vector< std::string >	getParametersForObservable ()
	A get method to get the parameters for the specific observable. More...
void	setBinMax (double max)
	A set method to set the maximum value of the bin. More...
void	setBinMin (double min)
	A set method to set the minimum value of the bin. More...
void	setParametersForObservable (std::vector< std::string > parametersForObservable_i)
	A set method to get the parameters for the specific observable. More...
	ThObservable (const StandardModel &SM_i)
	Constructor. More...
	ThObservable (const ThObservable &orig)
	The copy constructor. More...
virtual	~ThObservable ()
	The default destructor. More...

Additional Inherited Members
Protected Attributes inherited from ThObservable
double	max
	the bin maximum. More...
double	min
	The bin minimum. More...
std::vector< std::string >	parametersForObservable
	a vector of parameter namesfor the specific observable More...
const StandardModel &	SM
	A reference to an object of StandardMode class. More...

Constructor & Destructor Documentation

Pmunu()

Pmunu::Pmunu

(

const StandardModel &

SM_i

)

Constructor.

Parameters

[in]

SM_i

a reference to an object of type StandardModel

Definition at line 16 of file Pmunu.cpp.

: ThObservable(SM_i)
{
    
 
    setParametersForObservable(make_vector<std::string>() << "fK" << "delPl2em" << "fKofP");
    SM.initializeMeson(QCD::P_P);
    
};

Member Function Documentation

computeThValue()

double Pmunu::computeThValue ( )

virtual

arXiv:1605.07114

Returns

theoretical value of | \( \Gamma(\pi \rightarrow \lepton \nu) \)|

Implements ThObservable.

Definition at line 27 of file Pmunu.cpp.

{
    //The WC are written in the LEFT basis of arxiv:1709.04486 the expressions can be found in arxiv:1706.00410 and arxiv:1605.07114
    gslpp::vector<gslpp::complex> ** allcoeff_P_mu_nu = SM.getFlavour().ComputeCoeffdiujlknu(0,0,1,SM.getQuarks(QCD::UP).getMass_scale());
 
    double mP = SM.getMesons(QCD::P_P).getMass();
    
    double mu = SM.getQuarks(QCD::UP).getMass();
    double md = SM.getQuarks(QCD::DOWN).getMass();
    double mmu = SM.getLeptons(StandardModel::MU).getMass();
    
    double fP = SM.getOptionalParameter("fK") / SM.getOptionalParameter("fKofP"); // this is the pion decay constant in the SU(2)-symmetric limit 
    double delPl2em = SM.getOptionalParameter("delPl2em"); //this is the non-perturbative EM + strong isospin violation correction to the decay rate
    
    double amp2 = ((*(allcoeff_P_mu_nu[LO]))(0) -(*(allcoeff_P_mu_nu[LO]))(1) + mP * mP / (md+mu) / mmu * ((*(allcoeff_P_mu_nu[LO]))(2) - (*(allcoeff_P_mu_nu[LO]))(3))).abs2();
    
    //double WCnum = 1.0;
    //double WCden = 1.0;
   
    //return 1.;
    return 1. / (64. * M_PI) * mmu * mmu * mP * (1-mmu*mmu/mP/mP) * (1-mmu*mmu/mP/mP) * fP * fP * (1+delPl2em) * amp2 / HCUT;
 
}

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

• Pmunu.h
• Pmunu.cpp