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: EvtFlatte.cc
13 // Description: resonance-defining class
15 // Modification history:
17 // ponyisi 18 Feb 2008 created
19 //------------------------------------------------------------------------
21 #include "EvtGenBase/EvtPatches.hh"
23 #include "EvtGenBase/EvtVector4R.hh"
24 #include "EvtGenBase/EvtKine.hh"
25 #include "EvtGenBase/EvtComplex.hh"
26 #include "EvtGenBase/EvtFlatte.hh"
27 #include "EvtGenBase/EvtReport.hh"
28 #include "EvtGenBase/EvtConst.hh"
30 EvtFlatte::~EvtFlatte(){}
34 EvtFlatte& EvtFlatte::operator = ( const EvtFlatte &n)
36 if ( &n == this ) return *this;
55 EvtFlatte::EvtFlatte(const EvtVector4R& p4_p, const EvtVector4R& p4_d1,
56 const EvtVector4R& p4_d2, double ampl,
57 double theta, double mass,
58 vector<EvtFlatteParam>& params
59 // double m1a, double m1b, double g1,
60 // double m2a, double m2b, double g2
62 _p4_p(p4_p),_p4_d1(p4_d1), _p4_d2(p4_d2), _ampl(ampl), _theta(theta),
65 // _m1a(m1a), _m1b(m1b), _g1(g1),
66 // _m2a(m2a), _m2b(m2b), _g2(g2)
71 EvtComplex EvtFlatte::resAmpl() {
73 double pi180inv = 1.0/EvtConst::radToDegrees;
75 // EvtComplex ampl(cos(_theta*pi180inv), sin(_theta*pi180inv));
79 double mR = (_p4_d1+_p4_d2).mass();
83 for (vector<EvtFlatteParam>::const_iterator param = _params.begin();
84 param != _params.end();
87 double m1 = (*param).m1(); double m2 = (*param).m2();
88 double g = (*param).g();
90 *sqrtCplx((1-((m1-m2)*(m1-m2))/(mR*mR))*
91 (1-((m1+m2)*(m1+m2))/(mR*mR))));
92 // cout << m1 << " " << mR << " " << w << endl;
95 EvtComplex denom = _mass*_mass - mR*mR - EvtComplex(0,1)*w;
96 EvtComplex ampl = _ampl*EvtComplex(cos(_theta*pi180inv), sin(_theta*pi180inv))/denom;
97 // cout << abs(1/denom) << endl;