include/EvtGenModels/EvtYmSToYnSpipiCLEO.hh

0001
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0020
0021 #ifndef EVTYMSTOYNSPIPICLEO_HH
0022 #define EVTYMSTOYNSPIPICLEO_HH
0023
0024 // #include "EvtGenBase/EvtDecayProb.hh"
0025 #include "EvtGenBase/EvtDecayAmp.hh"
0026
0027 class EvtParticle;
0028
0029 // Description: This model is based on matrix element method used by
0030 //              CLEO in Phys.Rev.D76:072001,2007 to model the dipion mass
0031 //              and helicity angle distribution in the decays Y(mS) -> pi pi Y(nS),
0032 //              where m,n are integers and m>n and m<4.
0033 //              This model has two parameters, Re(B/A) and Im(B/A), which
0034 //              are coefficients of the matrix element's terms determined by
0035 //              the CLEO fits.
0036 //
0037 // Example:
0038 //
0039 // Decay  Upsilon(3S)
0040 //  1.0000    Upsilon      pi+  pi-     YMSTOYNSPIPICLEO -2.523 1.189;
0041 // Enddecay
0042 // Decay  Upsilon(3S)
0043 //  1.0000    Upsilon(2S)  pi+  pi-     YMSTOYNSPIPICLEO -0.395 0.001;
0044 // Enddecay
0045 // Decay  Upsilon(2S)
0046 //  1.0000    Upsilon      pi+  pi-     YMSTOYNSPIPICLEO -0.753 0.000;
0047 // Enddecay
0048 //
0049 //   --> the order of parameters is: Re(B/A) Im(B/A)
0050
0051 class EvtYmSToYnSpipiCLEO : public EvtDecayAmp {
0052     //EvtDecayProb  {
0053
0054   public:
0055     std::string getName() override;
0056     EvtDecayBase* clone() override;
0057
0058     void decay( EvtParticle* p ) override;
0059     void init() override;
0060     void initProbMax() override;
0061 };
0062
0063 #endif