The Center-of-mass angular distribution of direct photons at $S^{(1/2)}$ = 1.8-TeV observed with the D0 detector [report]

Paul Michael Rubinov
1995 unpublished
The study of center-of-mass angular distribution of direct photons produced in pp collisions at ..jS = l.8Te V with the D0 detector is described. The photons are detected and identified using a liquid argon calorimeter, with charged particle rejection provided by tracking chambers. The photons are restricted to the central region (11 ~ 0.75), but center-of-mass system for the hard scattering is reconstructed using the information from reconstructed jets. A method for avoiding possible bias due
more » ... possible bias due to edges of the calorimeter is presented. The background, due mainly to rare fragmentations l1l of a jet into a leading neutral meson, are subtracted statistically using the expected variation in the longitudinal profile of the electromagnetic shower. The angular distribution in the range of 1( from 0 to 1.5 (cos(}* from 0 to 0.9) is compared to next-to-leading order QCD predictions, and found to be in good agreement. lV This dissertation is dedicated to my parents.
doi:10.2172/1423659 fatcat:jfpfqug3djfcxcfdxjd6m25whe