include/EvtGenModels/EvtY3SToY1SpipiMoxhay.hh

0001
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0020
0021 #ifndef EVTY3STOY1SPIPIMOXHAY_HH
0022 #define EVTY3STOY1SPIPIMOXHAY_HH
0023
0024 #include "EvtGenBase/EvtDecayProb.hh"
0025
0026 class EvtParticle;
0027
0028 // Description: This model is based on the proposal by Tuan and Lipkin
0029 //              (Phys.Lett.B206:349-353,1988) and the subsequent model
0030 //              by Moxhay (Phys.Rev.D39:3497,1989) for the dipion spectrum
0031 //              in Y(3S) -> pi+ pi- Y(1S). Please Note: in Moxhay's paper,
0032 //              he wrote the fitted value of the parameter Im(B)/A as
0033 //              -0.2983. However, using his quoted value leads to the wrong
0034 //              spectrum. Changing the sign of his quoted Im(B)/A fixes the
0035 //              shape and reproduces his result. Therefore, please pass
0036 //              Im(B)/A = 0.2983 and Re(B)/A = 0.2196 to get the correct shape
0037 //              based on his fit to the CLEO data.
0038 //
0039 // Example:
0040 //
0041 // Decay  Upsilon(3S)
0042 //  1.0000    Upsilon  pi+  pi-     Y3STOY1SPIPIMOXHAY 0.2196 0.2983;
0043 // Enddecay
0044 //
0045 //   --> the order of parameters is: Re(B)/A Im(B)/A
0046
0047 class EvtY3SToY1SpipiMoxhay : public EvtDecayProb {
0048   public:
0049     std::string getName() override;
0050     EvtDecayBase* clone() override;
0051
0052     void decay( EvtParticle* p ) override;
0053     void init() override;
0054     void initProbMax() override;
0055 };
0056
0057 #endif