TPC Hit Errors (2008)


NOTE: this was for 2008

 These are the TPC hit errors as parameterized by Victor Perevoztchikov in order to normalize pulls (and thus chi squares) of ITTF tracks versus z, dip angle, and crossing angles:

error_xy = sqrt([0]+[1]*((200.-y)/100.)/(cos(x)*cos(x))+[2]*tan(x)*tan(x))
error_z  = sqrt([0]+[1]*((200.-y)/100.)*(1.+tan(x)*tan(x))+[2]*tan(x)*tan(x))

where y in the equations is the z coordinate in the TPC, and x in the equations is the crossing angle for error_xy, and the dip angle for error_z. The parameters are:

Inner TPC:

error_z ->SetParameters(0.00093415,0.0051781,0.014985);

Outer TPC:

error_z ->SetParameters(0.0026171,0.0045678,0.052361);

Plotting these as a function of z and crossing/dip angles gives:

Inner TPC:

Outer TPC:

EPS versions of these images are attached.