AliDecayer realisation for the EvtGen code and EvtGen itself.

[u/mrichter/AliRoot.git] / TEvtGen / EvtGenBase / EvtDalitzPoint.hh

diff --git a/TEvtGen/EvtGenBase/EvtDalitzPoint.hh b/TEvtGen/EvtGenBase/EvtDalitzPoint.hh
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+++ b/TEvtGen/EvtGenBase/EvtDalitzPoint.hh
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+/*******************************************************************************
+ * Project: BaBar detector at the SLAC PEP-II B-factory
+ * Package: EvtGenBase
+ *    File: $Id: EvtDalitzPoint.hh,v 1.10 2003/06/19 02:17:11 dvoretsk Exp $
+ *  Author: Alexei Dvoretskii, dvoretsk@slac.stanford.edu, 2001-2002
+ *
+ * Copyright (C) 2002 Caltech
+ *******************************************************************************/
+
+// This class describes the complete kinematics of the Dalitz decay.
+// It holds all the six invariant momentum products, three daughter
+// particle masses and three invariant masses of pairs of particles.
+// This description is completely symmetric with respect to particle 
+// permutations.
+//
+// Another way to slice the six coordinate is to make a transformation 
+// to the mass of the decaying particle. The four masses make up a 
+// Dalitz plot. The other two are coordinates of a point in the plot.
+
+#ifndef EVT_DALITZ_POINT_HH
+#define EVT_DALITZ_POINT_HH
+
+#include "EvtGenBase/EvtCyclic3.hh"
+#include "EvtGenBase/EvtDalitzCoord.hh"
+#include "EvtGenBase/EvtDalitzPlot.hh"
+
+class EvtDalitzPoint {
+
+public:
+
+  EvtDalitzPoint();
+  EvtDalitzPoint(double mA, double mB, double mC, 
+                double qAB, double qBC, double qCA);
+  EvtDalitzPoint(double mA, double mB, double mC, 
+                EvtCyclic3::Pair i, double qres, double qhel, double qsum);
+  EvtDalitzPoint(const EvtDalitzPlot&, const EvtDalitzCoord&);
+  EvtDalitzPoint(const EvtDalitzPoint& other);
+  ~EvtDalitzPoint();
+
+  EvtDalitzCoord getDalitzPoint(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
+  EvtDalitzPlot  getDalitzPlot() const;
+
+  double q(EvtCyclic3::Pair) const;
+  double bigM() const;
+  double m(EvtCyclic3::Index) const;
+
+  // Zemach variables
+
+  double qres(EvtCyclic3::Pair i) const;
+  double qhel(EvtCyclic3::Pair i) const;
+  double qsum() const;
+
+  // Kinematic quantities
+  //
+  // pp  - 4 momentum product
+  // e,p,cosTh - energy/moementum in rest-frame of j
+
+
+  double qMin(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
+  double qMax(EvtCyclic3::Pair i, EvtCyclic3::Pair j) const;
+  double pp(EvtCyclic3::Index i, EvtCyclic3::Index j) const; 
+  double e(EvtCyclic3::Index i, EvtCyclic3::Pair j) const;
+  double p(EvtCyclic3::Index i, EvtCyclic3::Pair j) const;
+  double cosTh(EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes) const;
+
+  bool isValid() const;
+
+  void print() const;
+
+private:
+
+  double _mA, _mB, _mC;     // masses
+  double _qAB, _qBC, _qCA;  // masses squared
+};
+
+#endif