include/EvtGenModels/EvtPFermi.hh

0001
0002 /***********************************************************************
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0020
0021 #ifndef EVTPFERMI_HH
0022 #define EVTPFERMI_HH
0023
0024 // Description:
0025 //   DFN model:
0026 //      F(k+) = N (1-x)^a exp((1+a)x) ,x=k+/(mB-mb)
0027 //      the fermi motion distribution according to
0028 //      hep-ph/9905351 v2
0029 //   BLNP model:
0030 //      F(what,Lambda,b) = pow(_b,_b)/(tgamma(_b)*_Lambda)*pow(what/_Lambda,_b-1)*
0031 //                           exp(-_b*what/Lambda);
0032 //      the leading order shape function (exp) (hep-ph/0504071)
0033
0034 class EvtPFermi final {
0035   public:
0036     // Constructors
0037
0038     EvtPFermi( const double& a, const double& mB, const double& mb );
0039     EvtPFermi( const double& Lambda, const double& b );
0040
0041     // Operators
0042
0043     // Selectors
0044
0045     // Modifiers
0046
0047     // Methods
0048
0049     double getFPFermi( const double& kplus );
0050     double getSFBLNP( const double& what );
0051
0052   protected:
0053     // Helper functions
0054
0055   private:
0056     // Friends
0057
0058     // Data members
0059
0060     double _a;
0061     double _mb;
0062     double _mB;
0063     double _Lambda;
0064     double _b;
0065 };
0066
0067 #endif    // EVTPFERMI_HH