EvtY3SToY1SpipiMoxhay.hh

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#ifndef EVTY3STOY1SPIPIMOXHAY_HH
#define EVTY3STOY1SPIPIMOXHAY_HH
 
#include "EvtGenBase/EvtDecayProb.hh"
 
class EvtParticle;
 
// Description: This model is based on the proposal by Tuan and Lipkin
//              (Phys.Lett.B206:349-353,1988) and the subsequent model
//              by Moxhay (Phys.Rev.D39:3497,1989) for the dipion spectrum
//              in Y(3S) -> pi+ pi- Y(1S). Please Note: in Moxhay's paper,
//              he wrote the fitted value of the parameter Im(B)/A as
//              -0.2983. However, using his quoted value leads to the wrong
//              spectrum. Changing the sign of his quoted Im(B)/A fixes the
//              shape and reproduces his result. Therefore, please pass
//              Im(B)/A = 0.2983 and Re(B)/A = 0.2196 to get the correct shape
//              based on his fit to the CLEO data.
//
// Example:
//
// Decay  Upsilon(3S)
//  1.0000    Upsilon  pi+  pi-     Y3STOY1SPIPIMOXHAY 0.2196 0.2983;
// Enddecay
//
//   --> the order of parameters is: Re(B)/A Im(B)/A
 
class EvtY3SToY1SpipiMoxhay : public EvtDecayProb {
  public:
    std::string getName() const override;
    EvtDecayBase* clone() const override;
 
    void decay( EvtParticle* p ) override;
    void init() override;
    void initProbMax() override;
};
 
#endif