Valid QCD sum rules for vector mesons in nuclear matter.

QCD sum rules for vector mesons (ρ, ω, φ) in nuclear matter are reexamined with an emphasis on the reliability of various sum rules. Monitoring the continuum contribution and the convergence of the operator product expansion plays crucial role in determining the validity of a sum rule. The uncertainties arising from less than precise knowledge of the condensate values and other input parameters are analyzed via a Monte-Carlo error analysis. Our analysis leaves no doubt that vector-meson masses decrease with increasing density. This resolves the current debate over the behavior of the vector-meson masses and the sum rules to be used in extracting vector meson properties in nuclear matter. We find a ratio of ρ-meson masses of mρ∗/mρ = 0.78±0.08 at nuclear matter saturation density. E-mail: [email protected] • Telephone: (604) 222-1047 ext. 6446 • Fax: (604) 222-1074 Present address: Dept. of Physics, Box 351560, University of Washington, Seattle, WA 98195. E-mail: [email protected] • Telephone: (206) 616–1447 • Fax: (206) 685–0635 WWW: http://www.phys.washington.edu/∼derek/Welcome.html