Comparison of Pion- and Proton-Production of Charmonium

Charmonium (chi) states produced in (pi)-beryllium interactions at 190 Gev/c and in proton-beryllium interactions at 200 Gev/c and 250 Gev/c have been observed via their decay into J/(PSI)+(gamma). This experiment was carried out with the Chicago Cyclotron Magnet Spectrometer at Fermilab. The fraction of J/(PSI)'s resulting from (chi) decay is measured to be 0.33 (+OR-) 0.07 for incident pions and 0.47 (+OR-) 0.21 for incident protons. The (chi)(3510) and (chi)(3555) are produced in roughly equal numbers for pions, but the (chi)(3555) dominates for protons. Simple gluon fusion accounts for (chi) production by protons. This is reasonable considering the lack of valence antiquarks in the proton-beryllium system. Other mechanisms are needed to explain (chi) production by pions.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Graff, Thomas Leo

• Physics, Elementary Particles and High Energy

Language dc:language

eng

Identifier

(UMI)AAI8502156

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/77372