Mass and width of the ρ-meson in a nuclear medium from Brown-Rho scaling and QCD sum rules
Abstract
We explore the range of values of the in-medium width of a ρ-meson at rest which is compatibale with the QCD sum rule approach in a nuclear medium assuming vector meson dominance and a Brown-Rho scaling law of the ρ-meson mass with the chiral condensate. The lower and upper bounds for the in-medium width are found to be strongly increasing with the decreasing mass of the ρ-meson (increasing nuclear density). We also study the bounds for the in-medium width in models not satisfying the Brown-Rho scaling law. It is shown that the in-medium width depends on how rapidly the mass decreases in comparison to the change of the quark condensate. The bounds for the in-medium width increase with density only if the relative change of the quark condensate is stronger than the relative decrease in mass. This is important for experimental tests of the Brown-Rho scaling paradigm and other dropping ρ-mass scenarios.
- Publication:
-
Physical Review C
- Pub Date:
- March 2006
- DOI:
- 10.1103/PhysRevC.73.034907
- arXiv:
- arXiv:hep-ph/0509134
- Bibcode:
- 2006PhRvC..73c4907R
- Keywords:
-
- 25.75.-q;
- Relativistic heavy-ion collisions;
- High Energy Physics - Phenomenology
- E-Print:
- Revised and extended version. In this version we also study the in-medium width for decreasing $\rho$-masses in models that do not satisfy the Brown-Rho scalin law