BesEvtGen-00-04-08/src/EvtGen/EvtGenModels/EvtbTosllAliFF.cc

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//--------------------------------------------------------------------------
//
// Environment:
//      This software is part of the EvtGen package developed jointly
//      for the BaBar and CLEO collaborations.  If you use all or part
//      of it, please give an appropriate acknowledgement.
//
// Copyright Information: See EvtGen/COPYRIGHT
//      Copyright (C) 2000      Caltech, UCSB
//
// Module: 
// Description: Form factors for b->sll according to Ali '02 et al.
//              PRD 66 34002
//
// Modification history:
//
//    Ryd     March 30, 2003         Module created
//
//------------------------------------------------------------------------
#include "EvtGenBase/EvtPatches.hh"
 
#include "EvtGenBase/EvtPatches.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenModels/EvtbTosllAliFF.hh"
#include <math.h>
 
EvtbTosllAliFF::EvtbTosllAliFF(){}
 
 
void EvtbTosllAliFF::getScalarFF(EvtId parent, EvtId daught,
                  double t, double mass, 
                  double& fp,double& f0,double& ft){
 
  double m=EvtPDL::getMeanMass(parent);
  //double md=EvtPDL::getMeanMass(daught);
  
  double shat=t/(m*m);
  double shat2=shat*shat;
  double shat3=shat2*shat;
 
  fp = 0.278*exp(1.568*shat+0.470*shat2+0.885*shat3);
  f0 = 0.278*exp(0.740*shat+0.080*shat2+0.425*shat3);
  ft = 0.300*exp(1.600*shat+0.501*shat2+0.796*shat3);
  
}
 
 
void EvtbTosllAliFF::getVectorFF(EvtId parent, EvtId daught,
                  double t, double mass, 
                  double& a1,double& a2,double& a0, double& v,
                  double& t1, double& t2, double& t3 ){
 
  
  double m=EvtPDL::getMeanMass(parent);
  //double md=EvtPDL::getMeanMass(daught);
  
  double shat=t/(m*m);
  double shat2=shat*shat;
 
  //this is Ali 'minimum allowed form factors'
  a1=0.294*exp(0.656*shat+0.456*shat2);
  a2=0.246*exp(1.237*shat+0.822*shat2);
  a0=0.412*exp(1.543*shat+0.954*shat2);
  v=0.399*exp(1.537*shat+1.123*shat2);
    
  t1=0.334*exp(1.575*shat+1.140*shat2);
  t2=0.334*exp(0.562*shat+0.481*shat2);
  t3=0.234*exp(1.230*shat+1.089*shat2);
 
}