Comparison of pion- and proton- production of charmonium
type: CreativeWork
description: "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."
abstract: "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."
author: Graff, Thomas Leo
language: en
keywords: pion production, proton production, charmonium, charmonium X states, proton-beryllium interactions
date published: 2011-06-07T15:28:19Z
date modified: 2026-07-22T22:25:24Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois - Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/25319