StRoot  1
EvtDalitzPoint.hh
1 /*******************************************************************************
2  * Project: BaBar detector at the SLAC PEP-II B-factory
3  * Package: EvtGenBase
4  * File: \$Id: EvtDalitzPoint.hh,v 1.1 2016/09/23 18:37:30 jwebb Exp \$
5  * Author: Alexei Dvoretskii, dvoretsk@slac.stanford.edu, 2001-2002
6  *
7  * Copyright (C) 2002 Caltech
8  *******************************************************************************/
9
10 // This class describes the complete kinematics of the Dalitz decay.
11 // It holds all the six invariant momentum products, three daughter
12 // particle masses and three invariant masses of pairs of particles.
13 // This description is completely symmetric with respect to particle
14 // permutations.
15 //
16 // Another way to slice the six coordinate is to make a transformation
17 // to the mass of the decaying particle. The four masses make up a
18 // Dalitz plot. The other two are coordinates of a point in the plot.
19
20 #ifndef EVT_DALITZ_POINT_HH
21 #define EVT_DALITZ_POINT_HH
22
23 #include "EvtGenBase/EvtCyclic3.hh"
24 #include "EvtGenBase/EvtDalitzCoord.hh"
25 #include "EvtGenBase/EvtDalitzPlot.hh"
26
28
29 public:
30
32  EvtDalitzPoint(double mA, double mB, double mC,
33  double qAB, double qBC, double qCA);
34  EvtDalitzPoint(double mA, double mB, double mC,
35  EvtCyclic3::Pair i, double qres, double qhel, double qsum);
37  EvtDalitzPoint(const EvtDalitzPoint& other);
38  ~EvtDalitzPoint();
39
40  EvtDalitzCoord getDalitzPoint(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
41  EvtDalitzPlot getDalitzPlot() const;
42
43  double q(EvtCyclic3::Pair) const;
44  double bigM() const;
45  double m(EvtCyclic3::Index) const;
46
47  // Zemach variables
48
49  double qres(EvtCyclic3::Pair i) const;
50  double qhel(EvtCyclic3::Pair i) const;
51  double qsum() const;
52
53  // Kinematic quantities
54  //
55  // pp - 4 momentum product
56  // e,p,cosTh - energy/moementum in rest-frame of j
57
58
59  double qMin(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
60  double qMax(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
61  double pp(EvtCyclic3::Index i, EvtCyclic3::Index j) const;
62  double e(EvtCyclic3::Index i, EvtCyclic3::Pair j) const;
63  double p(EvtCyclic3::Index i, EvtCyclic3::Pair j) const;
64  double cosTh(EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes) const;
65
66  bool isValid() const;
67
68  void print() const;
69
70 private:
71
72  double _mA, _mB, _mC; // masses
73  double _qAB, _qBC, _qCA; // masses squared
74 };
75
76 #endif