We will summarize the progress in understanding the changes in the vector meson spectral density in nuclear medium using the constraint equations obtained from the Borel transformed dispersion relation and QCD Operator Product Expansion. We will discuss the results for the scalar mass shift and dispersion effects (three momentum dependence) for the light quark system (ρ, ω), the strange quark system (φ) and the heavy quark system (J/ψ) in nuclear medium. For the light quark system, a nontrivial change in the mass and width is expected, while the dispersion effects are found to be small. Existing model calculations for the dispersion effects are compared to the constraint equation in detail. Very small, but accurate mass shifts are obtained for the heavy quark system.
Bibliographical noteFunding Information:
I would like to thank B. Friman, T. Hatsuda, H. Kim, S. Kim, F. Klingl, P. Morath and W. Weise for the collaboration, which this talk is based upon. This work was supported in part by KOSEF through grant no. 971-0204-017-2 and 976-0200-002-2 and the Korean Ministry of Education through grant no. 98-015-D00061.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics