[G12] p pi+ pi- exclusive Cross Section study

[Mukesh Saini]

Hello All,

For the plots and information from the study of p pi+ pi- exclusive Cross Section Follow the link at:

http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Omega_Cross-Section_Check#Apr_04

or 

http://www.jlab.org/~mukesh/Strangeonia/Analysis/yield_study_ppippim.pdf

The error bars are drawn on the plots 2 and 3 but they are almost invisible to the eye. The errors calculated were statistical : SQRT(Number of exclusive Events) and propogated through the calculations. Errors on gflux numbers were ignored (N_Photons >>> N_Events). 

Cut for the exclusive events are: 

Event with p pi+ pi- Detected &&
Event Within vertex &&  
TCut pppexc = "abs(mm_sq) <= 0.010 && abs(mm_pz) <= 0.100 && abs(mm_pt) <= 0.100";
 
No other Cuts are employed. 

Cross Section is calculated using the Formulae:

Cross Section = N_Events / N_Photons * (2.016 / 2) / (0.0717 * 40 * 6.022 * 10e+22 * Acceptance);

Cross Section = (Events/Beam Photons) * (Molar Weight of H2 / Number of H atoms) / (LH2 Density * Target Length * Avogadros Number * Acceptance)

I would like everyone to confirm that this is the way Cross Section is Calculated and all the Numbers in here are Correct. Else I have been obviously giving you guys all the wrong numbers.

Mukesh,
Graduate Student,
Florida State University.