Medium Modification of the Light Vector Mesons in Nuclei

Journal Article · Mon Oct 13 04:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3013045· OSTI ID:21251453

Nasseripour, R ^[1]; Djalali, C; Wood, M ^[2]; Weygand, D ^[3]

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1. George Washington University, Washington, DC 20052 (United States)
2. University of South Carolina, Columbia, SC 29208 (United States)
3. Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the {rho} vector mesons were investigated via their rare leptonic decay to e+e{sup -}. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The {rho} meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the rho meson in the nuclear medium rule out large medium effects. Transparency studies of the {omega} and {phi} vector mesons allows a determination of their widths in the medium.

• OSTI ID: 21251453
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1056; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CEBAF ACCELERATOR
CHIRAL SYMMETRY
ELECTRONS
FINAL-STATE INTERACTIONS
GEV RANGE 01-10
LEPTONIC DECAY
MASS DISTRIBUTION
MASS SPECTRA
NUCLEAR MATTER
OMEGA BARYONS
OMEGA-782 MESONS
PHI MESONS
PHOTONS
PHOTOPRODUCTION
QUANTUM CHROMODYNAMICS
RHO-770 MESONS
SPECTROMETERS
SYMMETRY BREAKING