In-Medium rho^0 Spectral Function Study via the 2H, 3He, 12C(gamma,pi+pi-) Reaction

Abstract

We report a helicity analysis of sub-threshold rho^0 production on 2H, 3He and 12C at low photo-production energies. The results are indicative of a large longitudinal rho^0 polarization (l=1, m=0) and are consistent with a strong helicity-flip production mechanism. This signature is used to extract in-medium rho^0_L invariant mass distributions for all three nuclei in a manner which is less model-dependent than previous measurements. The results are compared to kinematic and phenomenological models of the rho^0 spectral function. The 2H and 3He data distributions support the role of N*(1520) excitation in shaping the in-medium rho^0_L invariant mass distribution, while the 12C distributions are consistent with quasi-free rho^0_L production. The data support an in-medium modification of the rho^0_L invariant mass distribution.

29 pages, 23 figures

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Cited by in corpus (21)

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• The Chiral Restoration Transition of QCD and Low Mass Dileptons
• Light Vector Mesons in the Nuclear Medium
• Nuclear mass number dependence of inclusive production of omega and phi mesons in 12 GeV p + A collisions
• Medium Effects in rho-Meson Photoproduction
• Density Dependent Parametrization Models: Formalism and Applications
• Medium Modifications of the Rho Meson in Nuclear Photoproduction
• Unambiguous Extraction of the Electromagnetic Form Factors for Spin-1 Particles on the Light-Front
• Rho-meson properties in medium
• The $\pi \rho$ Cloud Contribution to the $\omega$ Width in Nuclear Matter
• Broadening of $\rho (\to e^{+}{e}^{-})$ meson produced coherently in the photonuclear reaction
• Low energy ω(\to π^0 γ) meson photoproduction in the nucleus
• Light Vector Mesons
• Holographic vector mesons in a hot and dense medium
• Effect of in-medium parameters of rho meson in its photoproduction reactions on nuclei
• ${\pi }^0\gamma$ invariant mass distribution in the low energy $\gamma p\to \omega p$ reaction
• $\rho N$ resonance dynamics in the proton nucleus reaction
• Velocity dependence of the mass modifications of $\rho$ and $\omega$ mesons in 12 GeV $p+A$ reactions