[u/mrichter/AliRoot.git] / TEvtGen / EvtGenModels / EvtHQET2FF.cxx

//--------------------------------------------------------------------------
//
// Module: EvtHQET2FF.cc
//
// Description: form factors for B->D*lnu & B->Dlnu according to HQET 
//              with dispersive FF
//
// Modification history:
//
//    Marco Bomben     March 10, 2003        Module created
//
//------------------------------------------------------------------------
// 
#include "EvtGenBase/EvtPatches.hh"
#include "EvtGenBase/EvtPatches.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenModels/EvtHQET2FF.hh"
#include "EvtGenBase/EvtId.hh"
#include <string>
#include "EvtGenBase/EvtPDL.hh"
#include <math.h>
#include <stdlib.h>


EvtHQET2FF::EvtHQET2FF(double hqetrho2, double hqetha1_1 , double hqetr1_1, double hqetr2_1) {

  rho2 = hqetrho2;
  r1_1 = hqetr1_1;
  r2_1 = hqetr2_1;
  ha1_1 = hqetha1_1;

  return;
}

EvtHQET2FF::EvtHQET2FF(double hqetrho2, double hqetv1_1) {

  rho2 = hqetrho2;
  v1_1 = hqetv1_1;

  return;
}


void EvtHQET2FF::getscalarff(EvtId parent,EvtId,
			    double t, double mass, double *f0p, double *f0m) {


  double mb=EvtPDL::getMeanMass(parent);
  double w = ((mb*mb)+(mass*mass)-t)/(2.0*mb*mass);

// Form factors have a general form, with parameters passed in
// from the arguements.

  // Use disparsion relation parametrization from 
  // I.Caprini, L.Lelluch, M.Neubert, Nucl. Phys. B 530,153(1998)
  const double z = (sqrt(w+1)-sqrt(2.))/(sqrt(w+1)+sqrt(2.));
  double v1 = v1_1*(1.- 8.*rho2*z + (51.*rho2-10.)*z*z - (252.*rho2-84.)*z*z*z)
;

  *f0p=v1;
  *f0m = 0.0;

  return;
 }

void EvtHQET2FF::getvectorff(EvtId parent,EvtId,
			    double t, double mass, double *a1f,
			    double *a2f, double *vf, double *a0f ){


  double mb=EvtPDL::getMeanMass(parent);
  double w = ((mb*mb)+(mass*mass)-t)/(2.0*mb*mass);

// Form factors have a general form, with parameters passed in
// from the arguements.

  double rstar = ( 2.0*sqrt(mb*mass))/(mb+mass);

  // Use disparsion relation parametrization from 
  // I.Caprini, L.Lelluch, M.Neubert, Nucl. Phys. B 530,153(1998)
  const double z = (sqrt(w+1)-sqrt(2.))/(sqrt(w+1)+sqrt(2.));
  double ha1 =ha1_1*(1.- 8.*rho2*z + (53.*rho2-15.)*z*z - (231.*rho2-91.)*z*z*z);
  double r1 = r1_1-0.12*(w-1)+0.05*(w-1)*(w-1);
  double r2 = r2_1+0.11*(w-1)-0.06*(w-1)*(w-1);
;

  *a1f = (1.0 - (t/((mb+mass)*(mb+mass))))*ha1;
  *a1f = (*a1f)/rstar;
  *a2f = (r2/rstar)*ha1;
  *vf = (r1/rstar)*ha1;
  *a0f = 0.0;

  return;
 }

void EvtHQET2FF::gettensorff(EvtId, EvtId, double, double, double*, 
			       double*, double*, double*){
  
  report(ERROR,"EvtGen") << "Not implemented :gettensorff in EvtHQET2FF.\n";  
  ::abort();

}


void EvtHQET2FF::getbaryonff(EvtId, EvtId, double, double, double*, 
			       double*, double*, double*){
  
  report(ERROR,"EvtGen") << "Not implemented :getbaryonff in EvtHQET2FF.\n";  
  ::abort();

}
Commit	Line	Data
da0e9ce3	1	//--------------------------------------------------------------------------
	2	//
	3	// Module: EvtHQET2FF.cc
	4	//
	5	// Description: form factors for B->D*lnu & B->Dlnu according to HQET
	6	// with dispersive FF
	7	//
	8	// Modification history:
	9	//
	10	// Marco Bomben March 10, 2003 Module created
	11	//
	12	//------------------------------------------------------------------------
	13	//
	14	#include "EvtGenBase/EvtPatches.hh"
	15	#include "EvtGenBase/EvtPatches.hh"
	16	#include "EvtGenBase/EvtReport.hh"
	17	#include "EvtGenModels/EvtHQET2FF.hh"
	18	#include "EvtGenBase/EvtId.hh"
	19	#include <string>
	20	#include "EvtGenBase/EvtPDL.hh"
	21	#include <math.h>
	22	#include <stdlib.h>
	23
	24
	25	EvtHQET2FF::EvtHQET2FF(double hqetrho2, double hqetha1_1 , double hqetr1_1, double hqetr2_1) {
	26
	27	rho2 = hqetrho2;
	28	r1_1 = hqetr1_1;
	29	r2_1 = hqetr2_1;
	30	ha1_1 = hqetha1_1;
	31
	32	return;
	33	}
	34
	35	EvtHQET2FF::EvtHQET2FF(double hqetrho2, double hqetv1_1) {
	36
	37	rho2 = hqetrho2;
	38	v1_1 = hqetv1_1;
	39
	40	return;
	41	}
	42
	43
	44	void EvtHQET2FF::getscalarff(EvtId parent,EvtId,
	45	double t, double mass, double f0p, double f0m) {
	46
	47
	48	double mb=EvtPDL::getMeanMass(parent);
	49	double w = ((mbmb)+(massmass)-t)/(2.0mbmass);
	50
	51	// Form factors have a general form, with parameters passed in
	52	// from the arguements.
	53
	54	// Use disparsion relation parametrization from
	55	// I.Caprini, L.Lelluch, M.Neubert, Nucl. Phys. B 530,153(1998)
	56	const double z = (sqrt(w+1)-sqrt(2.))/(sqrt(w+1)+sqrt(2.));
	57	double v1 = v1_1(1.- 8.rho2z + (51.rho2-10.)zz - (252.rho2-84.)zzz)
	58	;
	59
	60	*f0p=v1;
	61	*f0m = 0.0;
	62
	63	return;
	64	}
65
66	void EvtHQET2FF::getvectorff(EvtId parent,EvtId,
67	double t, double mass, double *a1f,
68	double a2f, double vf, double *a0f ){
69
70
71	double mb=EvtPDL::getMeanMass(parent);
72	double w = ((mbmb)+(massmass)-t)/(2.0mbmass);
73
74	// Form factors have a general form, with parameters passed in
75	// from the arguements.
76
77	double rstar = ( 2.0sqrt(mbmass))/(mb+mass);
78
79	// Use disparsion relation parametrization from
80	// I.Caprini, L.Lelluch, M.Neubert, Nucl. Phys. B 530,153(1998)
81	const double z = (sqrt(w+1)-sqrt(2.))/(sqrt(w+1)+sqrt(2.));
82	double ha1 =ha1_1(1.- 8.rho2z + (53.rho2-15.)zz - (231.rho2-91.)zzz);
83	double r1 = r1_1-0.12(w-1)+0.05(w-1)*(w-1);
84	double r2 = r2_1+0.11(w-1)-0.06(w-1)*(w-1);
85	;
86
87	a1f = (1.0 - (t/((mb+mass)(mb+mass))))*ha1;
88	a1f = (a1f)/rstar;
89	a2f = (r2/rstar)ha1;
90	vf = (r1/rstar)ha1;
91	*a0f = 0.0;
92
93	return;
94	}
95
96	void EvtHQET2FF::gettensorff(EvtId, EvtId, double, double, double*,
97	double, double, double*){
98
99	report(ERROR,"EvtGen") << "Not implemented :gettensorff in EvtHQET2FF.\n";
100	::abort();
101
102	}
103
104
105
106	void EvtHQET2FF::getbaryonff(EvtId, EvtId, double, double, double*,
107	double, double, double*){
108
109	report(ERROR,"EvtGen") << "Not implemented :getbaryonff in EvtHQET2FF.\n";
110	::abort();
111
112	}