Measurement of Hadronically Produced $^3P$ State Charmonium at $\sqrt{s}$ = 23.7-GeV

Abstract

Fermilab experiment E705 measured the inclusive production ratio for the two higher mass 1 3 P 1 charmonium states, uxif ux 2 , for 300 GeV /c proton a.nd ,r± beams interacting with a lithium target. Our measu~ed ratios of o.os::g:i~ a.nd 0.52::g:~~ for proton a.nd pion induced reactions, respectively, show good agreement with previous experiments. The production ratio for proton data is consista.nt with a gluon fusion model for p-wave charmonium, while the pion ratio could be represented by a strict color evaporation model or an admixture of different mechanisms. Total production cross sections were measured for the individual chi states using both beam types. Differential cross sections in transverse momentum and Feynman x were also measured for the combined x 1 + x 2 signal. The differential cross sections a.re qualititatively similar to those for the J /psi a.nd show a transverse momentum dependence of eaPr with a sharper fall off for proton beam, a=-1.47 ± 0.25 (GeV /ct 1 , compared with that for pion beams, a=-1.39 ± 0.14 (GeV /c)-1. Angular distributions of the decay photon a.nd positive muon were a.lso measured for reactions induced by all beam types but are consistant with the predictions of all production mechanism hypotheses. There were many people who helped either directly or indirectly and deserve some credit for the preparation of this dissertation. First and formost my gratitude is extended to my advisor and mentor, Lloyd Fortney. He was always available with an intuitive explanation whenever I had a question. He was also instrumental in keeping this work to a single volume. There are also the many people who shared the "E705 challenge" and helped to make the experiment an unforgettable experience and keeping a perspective amid the chaos of alarms, exploding targets and heated group meetings. Steve Delchamps, Ting Yang Chen, and Marzia Rosati helped me in various aspects of the analysis and provided a testbed for some of my ideas. The other members of the Duke contingent, Shen Qifeng and Tim Turkington are included here for thier contributions to the analysis code. Much of my mental stability I owe to my fellow graduate students and the faculty and staff in the high energy physics group: