CDF dE/dx Parameterization Studies

Presentations

May 28, 2004 dedx_status.pdf dedx_status.ppt
May 12, 2004 evenmore_dedx.pdf evenmore_dedx.ppt
May 4, 2004 more_dedx.pdf more_dedx.ppt
April 20, 2004 lowpt_dedx.pdf lowpt_dedx.ppt

Universal curve parameterizations, version 2.0

The following parameters were generated using TOF+dE/dx data and delta cot(theta)+dE/dx from conversions. Energy loss corrections were applied using the 2/25/2004 version of CT_DedxAnalysis with an additional momentum-dependent correction provided by Stefano and Vivek. The universal curve is still parameterized by the function: 
double uc(double *y,double *par) {
  double c0 = par[0];
  double c1 = par[1];
  double b = par[2];
  double a1 = par[3];
  double a2 = par[4];
  double c = par[5];
  double mass = par[6];             //  Particle mass hypothesis
  double x = y[0]/mass;             //  y[0] is momentum, x is beta*gamma
  double t = x/sqrt(1+x*x);         //  t is beta
  return (c1*log(x/(x+b)) + c0)/(t*t) + a1*(t-1) + a2*(t-1)*(t-1) + c;
}
and the resolution on the quantity Z=log[dEdx(measured)/dEdx(predicted)] is still parameterized by: 
double res(double *y,double *par) {
  double n0 = par[0];
  double sigma = par[1];
  double b = par[2];
  double c = par[3];
  double n = y[0];           //  Number of dE/dx hits
  double uc = y[1];          //  Predicted dE/dx
  return (sigma+c*(uc-15.0))*pow(n/n0,b);
}
There are separate sets of parameters for positive and negative tracks.

Universal curve parameterizations, version 1.0

The following parameters were generated using TOF+dE/dx data and delta cot(theta)+dE/dx from conversions. Energy loss corrections were applied using the 2/25/2004 version of CT_DedxAnalysis. The universal curve is parameterized by the function: 
double uc(double *y,double *par) {
  double c0 = par[0];
  double c1 = par[1];
  double b = par[2];
  double a1 = par[3];
  double a2 = par[4];
  double c = par[5];
  double mass = par[6];             //  Particle mass hypothesis
  double x = y[0]/mass;             //  y[0] is momentum, x is beta*gamma
  double t = x/sqrt(1+x*x);         //  t is beta
  return (c1*log(x/(x+b)) + c0)/(t*t) + a1*(t-1) + a2*(t-1)*(t-1) + c;
}
and the resolution on the quantity Z=log[dEdx(measured)/dEdx(predicted)] is parameterized by: 
double res(double *y,double *par) {
  double n0 = par[0];
  double sigma = par[1];
  double b = par[2];
  double c = par[3];
  double n = y[0];           //  Number of dE/dx hits
  double uc = y[1];          //  Predicted dE/dx
  return (sigma+c*(uc-15.0))*pow(n/n0,b);
}
There are separate sets of parameters for positive and negative tracks.