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/EvtPDL.hh"
#include "../EvtGenBase/EvtPatches.hh"
#include "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 );
}