1 //--------------------------------------------------------------------------
4 // This software is part of the EvtGen package developed jointly
5 // for the BaBar and CLEO collaborations. If you use all or part
6 // of it, please give an appropriate acknowledgement.
8 // Copyright Information: See EvtGen/COPYRIGHT
9 // Copyright (C) 1998 Caltech, UCSB
11 // Module: EvtGen/EvtResonance.hh
13 // Description:resonance-defining class
15 // Modification history:
17 // NK September 4, 1997 Module created
19 //------------------------------------------------------------------------
21 #ifndef EVTRESONANCE_HH
22 #define EVTRESONANCE_HH
24 #include "EvtGenBase/EvtVector4R.hh"
33 EvtResonance& operator = (const EvtResonance &);
35 //constructor with all information about the resonance
36 EvtResonance(const EvtVector4R& p4_p, const EvtVector4R& p4_d1,
37 const EvtVector4R& p4_d2,
38 double ampl = 0.0, double theta = 0.0, double gamma = 0.0,
39 double bwm = 0.0, int spin = 0);
42 virtual ~EvtResonance();
45 //return 4-momenta of the particles involved
46 inline const EvtVector4R& p4_p() { return _p4_p; }
47 inline const EvtVector4R& p4_d1() { return _p4_d1; }
48 inline const EvtVector4R& p4_d2() { return _p4_d2; }
52 inline double amplitude() { return _ampl; }
55 inline double theta() { return _theta; }
58 inline double gamma() { return _gamma; }
61 inline double bwm() { return _bwm; }
64 inline int spin() { return _spin; }
66 //calculate amplitude for this resonance
69 //calculate relativistic Breit-Wigner amplitude for P-decays of scalars
70 EvtComplex relBrWig(int i);
74 EvtVector4R _p4_p, _p4_d1, _p4_d2;
75 double _ampl, _theta, _gamma, _bwm;