61 {
62
64
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82 double mAB=(_p4_d1+_p4_d2).
mass();
83 double mBC=(_p4_d2+p4_d3).
mass();
84 double mAC=(_p4_d1+p4_d3).
mass();
85 double mA=_p4_d1.
mass();
86 double mB=_p4_d2.mass();
87 double mD=_p4_p.
mass();
88 double mC=p4_d3.
mass();
89
90 double mR=_bwm;
91 double gammaR=_gamma;
92 double mdenom = _invmass_angdenom ? mAB : mR;
93 double pAB=sqrt( (((mAB*mAB-mA*mA-mB*mB)*(mAB*mAB-mA*mA-mB*mB)/4.0) -
94 mA*mA*mB*mB)/(mAB*mAB));
95 double pR=sqrt( (((mR*mR-mA*mA-mB*mB)*(mR*mR-mA*mA-mB*mB)/4.0) -
96 mA*mA*mB*mB)/(mR*mR));
97
98 double md = _use_mD?mD:mR;
99 double pD= (((mD*mD-mR*mR-mC*mC)*(mD*mD-mR*mR-mC*mC)/4.0) -
100 mR*mR*mC*mC)/(md*md);
101 if ( pD>0 ) { pD=sqrt(pD); } else {pD=0;}
102 md = _use_mD?mD:mAB;
103 double pDAB=sqrt( (((mD*mD-mAB*mAB-mC*mC)*(mD*mD-mAB*mAB-mC*mC)/4.0) -
104 mAB*mAB*mC*mC)/(md*md));
105
106
107
108
109
110 double fR=1;
111 double fD=1;
112 int power=0;
113 switch (_spin) {
114 case 0:
115 fR=1.0;
116 fD=1.0;
117 power=1;
118
119 break;
120 case 1:
121 fR=sqrt(1.0+1.5*1.5*pR*pR)/sqrt(1.0+1.5*1.5*pAB*pAB);
122 fD=sqrt(1.0+5.0*5.0*pD*pD)/sqrt(1.0+5.0*5.0*pDAB*pDAB);
123
124 power=3;
125 break;
126 case 2:
127 fR = sqrt( (9+3*pow((1.5*pR),2)+pow((1.5*pR),4))/(9+3*pow((1.5*pAB),2)+pow((1.5*pAB),4)) );
128 fD = sqrt( (9+3*pow((5.0*pD),2)+pow((5.0*pD),4))/(9+3*pow((5.0*pDAB),2)+pow((5.0*pDAB),4)) );
129 power=5;
130 break;
131 default:
132 report(
INFO,
"EvtGen") <<
"Incorrect spin in EvtResonance22.cc\n";
133 }
134
135 double gammaAB= gammaR*pow(pAB/pR,power)*(mR/mAB)*fR*fR;
136
137 switch (_spin) {
138 case 0:
140 fR*fD/(mR*mR-mAB*mAB-
EvtComplex(0.0,mR*gammaAB));
141 break;
142 case 1:
144 (fR*fD*(mAC*mAC-mBC*mBC+((mD*mD-mC*mC)*(mB*mB-mA*mA)/(mdenom*mdenom)))/
145
147 break;
148 case 2:
150 fR*fD/(mR*mR-mAB*mAB-
EvtComplex(0.0,mR*gammaAB))*
151 (pow((mBC*mBC-mAC*mAC+(mD*mD-mC*mC)*(mA*mA-mB*mB)/(mdenom*mdenom)),2)-
152 (1.0/3.0)*(mAB*mAB-2*mD*mD-2*mC*mC+pow((mD*mD- mC*mC)/mdenom, 2))*
153 (mAB*mAB-2*mA*mA-2*mB*mB+pow((mA*mA-mB*mB)/mdenom,2)));
154 break;
155
156 default:
157 report(
INFO,
"EvtGen") <<
"Incorrect spin in EvtResonance22.cc\n";
158 }
159
160
161 return ampl;
162}
double sin(const BesAngle a)
double cos(const BesAngle a)
ostream & report(Severity severity, const char *facility)
static const double radToDegrees