STUDY OF CHARMONIUM CHI STATES PRODUCED IN PROTON AND NEGATIVE PION INTERACTIONS WITH A BERYLLIUM TARGET (J/PSI, SINGLET, EVAPORATION, E673)
Abstract
We have observed the production of charmonium in (pi)('-)-Be interactions at 190 GeV and p-Be interactions at 200 and 250 GeV. We detected the states (chi)(3510) and (chi)(3555) ((chi)(,1) and (chi)(,2)) through their decay to J/(psi) + (gamma). For (pi)('-) production we measured (sigma)((chi)(,1))/(sigma)((chi)(,2)) = 1.2 (+OR-) .8 and found the fraction of J/(psi)s coming from (chi) decay (F(,(psi)(chi))) to be .35 (+OR-) .13. We see no clear (chi)(,1) signal in the proton sample, so we quote a 90% confidence level upper limit of (sigma)((chi)(,1))/(sigma)((chi)(,2)) < .72. We measure F(,(psi)(chi)) = .54 (+OR-) .25 for production by a proton beam. The J/(psi) samples for each beam were divided in half based on the x(,F) of the J/(psi). In the (pi)('-) sample of J/(psi)s with x(,F) (GREATERTHEQ) .43 we found (sigma)((chi)(,1))(sigma)((chi)(,2)) = .70 (+OR-) .44 and F(,(psi)(chi)) = .41 (+OR-) .16; for the (pi)('-) sample with x(,F) < .43, F(,(psi)(chi)) = .27 (+OR-) .11. In the proton sample of J/(psi)s with x(,F) (GREATERTHEQ) .31 we found F(,(psi)(chi)) = .77 (+OR-) .42 and for J/(psi)s with x(,F) < .31 we found F(,(psi)(chi)) = .24 (+OR-) .38. The differences in charmonium production for different beam particles and x(,F) regions disagree with the predictions of the color nonsinglet model. It may be possible to account for these differences using color singlet processes only.
Degree
Ph.D.
Subject Area
Particle physics
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