CGEM BOSS 6.6.5.i
BESIII Offline Software System
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Public Member Functions | List of all members
EvtResonance2 Class Reference

#include <EvtResonance2.hh>

Public Member Functions

EvtResonance2 & operator= (const EvtResonance2 &)
 
 EvtResonance2 (const EvtVector4R &p4_p, const EvtVector4R &p4_d1, const EvtVector4R &p4_d2, double ampl=0.0, double theta=0.0, double gamma=0.0, double bwm=0.0, int spin=0, bool invmass_angdenom=false)
 
virtual ~EvtResonance2 ()
 
const EvtVector4R & p4_p ()
 
const EvtVector4R & p4_d1 ()
 
const EvtVector4R & p4_d2 ()
 
double amplitude ()
 
double theta ()
 
double gamma ()
 
double bwm ()
 
int spin ()
 
EvtComplex resAmpl ()
 

Detailed Description

Definition at line 31 of file EvtResonance2.hh.

Constructor & Destructor Documentation

◆ EvtResonance2()

EvtResonance2::EvtResonance2 ( const EvtVector4R & p4_p,
const EvtVector4R & p4_d1,
const EvtVector4R & p4_d2,
double ampl = 0.0,
double theta = 0.0,
double gamma = 0.0,
double bwm = 0.0,
int spin = 0,
bool invmass_angdenom = false )

Definition at line 51 of file EvtResonance2.cc.

54 : ////////////////////////////////////////////////////
55 _p4_p(p4_p),_p4_d1(p4_d1), _p4_d2(p4_d2),_ampl(ampl), _theta(theta),
56 _gamma(gamma), _bwm(bwm), _spin(spin), _invmass_angdenom(invmass_angdenom) {}///////////////////////////////////////////////////////////////////
EvtResonance2::p4_d2
const EvtVector4R & p4_d2()
Definition EvtResonance2.hh:50
EvtResonance2::p4_p
const EvtVector4R & p4_p()
Definition EvtResonance2.hh:48
EvtResonance2::p4_d1
const EvtVector4R & p4_d1()
Definition EvtResonance2.hh:49

◆ ~EvtResonance2()

EvtResonance2::~EvtResonance2 ( )
virtual

Definition at line 30 of file EvtResonance2.cc.

30{}

Member Function Documentation

◆ amplitude()

double EvtResonance2::amplitude ( )
inline

Definition at line 54 of file EvtResonance2.hh.

54{ return _ampl; }

◆ bwm()

double EvtResonance2::bwm ( )
inline

Definition at line 63 of file EvtResonance2.hh.

63{ return _bwm; }

◆ gamma()

double EvtResonance2::gamma ( )
inline

Definition at line 60 of file EvtResonance2.hh.

60{ return _gamma; }

◆ operator=()

EvtResonance2 & EvtResonance2::operator= ( const EvtResonance2 & n)

Definition at line 34 of file EvtResonance2.cc.

35{
36 if ( &n == this ) return *this;
37 _p4_p = n._p4_p;
38 _p4_d1 = n._p4_d1;
39 _p4_d2 = n._p4_d2;
40 _ampl = n._ampl;
41 _theta = n._theta;
42 _gamma = n._gamma;
43 _spin = n._spin;
44 _bwm = n._bwm;
45 _invmass_angdenom = n._invmass_angdenom;
46 return *this;
47}
n
const Int_t n
Definition DataBase/tau_mode.c:65

◆ p4_d1()

const EvtVector4R & EvtResonance2::p4_d1 ( )
inline

Definition at line 49 of file EvtResonance2.hh.

49{ return _p4_d1; }

◆ p4_d2()

const EvtVector4R & EvtResonance2::p4_d2 ( )
inline

Definition at line 50 of file EvtResonance2.hh.

50{ return _p4_d2; }

◆ p4_p()

const EvtVector4R & EvtResonance2::p4_p ( )
inline

Definition at line 48 of file EvtResonance2.hh.

48{ return _p4_p; }

◆ resAmpl()

EvtComplex EvtResonance2::resAmpl ( )

Definition at line 60 of file EvtResonance2.cc.

60 {
61
62 double pi180inv = 1.0/EvtConst::radToDegrees;
63
64 EvtComplex ampl;
65 EvtVector4R p4_d3 = _p4_p-_p4_d1-_p4_d2;
66
67 //get cos of the angle between the daughters from their 4-momenta
68 //and the 4-momentum of the parent
69
70 //in general, EvtDecayAngle(parent, part1+part2, part1) gives the angle
71 //the missing particle (not listed in the arguments) makes
72 //with part2 in the rest frame of both
73 //listed particles (12)
74
75 //angle 3 makes with 2 in rest frame of 12 (CS3)
76 //double cos_phi_0 = EvtDecayAngle(_p4_p, _p4_d1+_p4_d2, _p4_d1);
77 //angle 3 makes with 1 in 12 is, of course, -cos_phi_0
78
79 //first compute several quantities...follow CLEO preprint 00-23
80
81 double mAB=(_p4_d1+_p4_d2).mass();
82 double mBC=(_p4_d2+p4_d3).mass();
83 double mAC=(_p4_d1+p4_d3).mass();
84 double mA=_p4_d1.mass();
85 double mB=_p4_d2.mass();
86 double mD=_p4_p.mass();
87 double mC=p4_d3.mass();
88
89 double mR=_bwm;
90 double gammaR=_gamma;
91 double mdenom = _invmass_angdenom ? mAB : mR;/////////////////////////////////////////////////////////
92 double pAB=sqrt( (((mAB*mAB-mA*mA-mB*mB)*(mAB*mAB-mA*mA-mB*mB)/4.0) -
93 mA*mA*mB*mB)/(mAB*mAB));
94 double pR=sqrt( (((mR*mR-mA*mA-mB*mB)*(mR*mR-mA*mA-mB*mB)/4.0) -
95 mA*mA*mB*mB)/(mR*mR));
96
97 double pD= (((mD*mD-mR*mR-mC*mC)*(mD*mD-mR*mR-mC*mC)/4.0) -
98 mR*mR*mC*mC)/(mD*mD);
99 if ( pD>0 ) { pD=sqrt(pD); } else {pD=0;}
100 double pDAB=sqrt( (((mD*mD-mAB*mAB-mC*mC)*(mD*mD-mAB*mAB-mC*mC)/4.0) -
101 mAB*mAB*mC*mC)/(mD*mD));
102
103
104 // report(INFO,"EvtGen") << mAB<<" "<< mBC<<" "<< mAC<<" "<< mA<<" "<< mB<<" "<< mC<<" "
105 // << mD<<" "<< mR<<" "<< gammaR<<" "<< pAB<<" "<< pR<<" "<< pD<<" "<<pDAB<<endl;
106
107 double fR=1;
108 double fD=1;
109 int power=0;
110 switch (_spin) {
111 case 0:
112 fR=1.0;
113 fD=1.0;
114 power=1;
115 //report(INFO,"EvtGen") << "fR="<<fR<<" fD="<<fD<<endl;
116 break;
117 case 1:
118 fR=sqrt(1.0+1.5*1.5*pR*pR)/sqrt(1.0+1.5*1.5*pAB*pAB);
119 fD=sqrt(1.0+5.0*5.0*pD*pD)/sqrt(1.0+5.0*5.0*pDAB*pDAB);
120 //report(INFO,"EvtGen") << "fR="<<fR<<" fD="<<fD<<endl;
121 power=3;
122 break;
123 case 2:///////////////////////////////////////////////////////////
124 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)) );//////////////////////////////////////////////////////////
125 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)) );//////////////////////////////////////////////////
126 power=5;///////////////////////////////////////////////////
127 break;///////////////////////////////////////////////////////////
128 default:
129 report(INFO,"EvtGen") << "Incorrect spin in EvtResonance22.cc\n";
130 }
131
132 double gammaAB= gammaR*pow(pAB/pR,power)*(mR/mAB)*fR*fR;
133 //report(INFO,"EvtGen") << gammaAB<<endl;
134 switch (_spin) {
135 case 0:
136 ampl=_ampl*EvtComplex(cos(_theta*pi180inv),sin(_theta*pi180inv))*
137 fR*fD/(mR*mR-mAB*mAB-EvtComplex(0.0,mR*gammaAB));
138 break;
139 case 1:
140 ampl=_ampl*EvtComplex(cos(_theta*pi180inv),sin(_theta*pi180inv))*
141 (fR*fD*(mAC*mAC-mBC*mBC+((mD*mD-mC*mC)*(mB*mB-mA*mA)/(mdenom*mdenom)))/ //////////////////////////////////////////////////////////////////
142 //(fR*fD*(mAC*mAC-mBC*mBC+((mD*mD-mC*mC)*(mB*mB-mA*mA)/(mR*mR)))/
143 (mR*mR-mAB*mAB-EvtComplex(0.0,mR*gammaAB)));
144 break;
145 case 2:
146 ampl=_ampl*EvtComplex(cos(_theta*pi180inv),sin(_theta*pi180inv))*
147 fR*fD/(mR*mR-mAB*mAB-EvtComplex(0.0,mR*gammaAB))*
148 (pow((mBC*mBC-mAC*mAC+(mD*mD-mC*mC)*(mA*mA-mB*mB)/(mdenom*mdenom)),2)-
149 (1.0/3.0)*(mAB*mAB-2*mD*mD-2*mC*mC+pow((mD*mD- mC*mC)/mdenom, 2))*
150 (mAB*mAB-2*mA*mA-2*mB*mB+pow((mA*mA-mB*mB)/mdenom,2)));
151 break;
152
153 default:
154 report(INFO,"EvtGen") << "Incorrect spin in EvtResonance22.cc\n";
155 }
156
157 //report(INFO,"EvtGen") <<"The amplitude is "<<ampl<<endl;
158 return ampl;
159}
sin
double sin(const BesAngle a)
Definition BesAngle.h:210
cos
double cos(const BesAngle a)
Definition BesAngle.h:213
mass
double mass
Definition CosmicGenerator.cxx:138
report
ostream & report(Severity severity, const char *facility)
Definition EvtReport.cc:36
INFO
@ INFO
Definition EvtReport.hh:52
EvtConst::radToDegrees
static const double radToDegrees
Definition EvtConst.hh:30
EvtVector4R::mass
double mass() const
Definition EvtVector4R.cc:39

Referenced by EvtDDalitz::decay().

◆ spin()

int EvtResonance2::spin ( )
inline

Definition at line 66 of file EvtResonance2.hh.

66{ return _spin; }

◆ theta()

double EvtResonance2::theta ( )
inline

Definition at line 57 of file EvtResonance2.hh.

57{ return _theta; }
The documentation for this class was generated from the following files: