Comparison of pion- and proton- production of charmonium

"Charmonium X 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/'+y. This experiment was carried out with the Chicago Cyclotron Magnet Spectrometer at Fermilab. The fraction of J/""s resulting from X decay is measured to be 0.33±O.07 for incident pions and 0.47±0.2l for incident protons. The X(35l0) and X(3555) are produced in roughly equal numbers for pions, but the X(3555) dominates for protons. Simple gluon fusion accounts for X production by protons. This is reasonable considering the lack of valence antiquarks in the proton-beryllium system. Other mechanisms are needed to explain X production by pions."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Graff, Thomas Leo

Contributors dc:contributor

• Koester, L.J.

• pion production
• proton production
• charmonium
• charmonium X states
• proton-beryllium interactions

Statement dc:rights

• 1984 Thomas Leo Graff

Language dc:language

en

Identifier

4786502

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25319