The spectral function of the rho meson in nuclear matter

✍ Scribed by W. Peters; M. Post; H. Lenske; S. Leupold; U. Mosel

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 918 KB
• Volume: 632
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(98)00803-3

✦ Synopsis

We calculate the modification of a rho meson in nuclear matter through its coupling to resonance-hole states. Starting from a recently proposed model, we include all four star resonances up to 1.9 GeV. In contrast to previous works, we include not only resonances that couple to the rho in a relative p-wave, but also those that couple to an s-wave state. In addition, we solve the equation for the rho spectral function self-consistently. We find that s-wave resonances affect the in medium spectral function of the rho strongly. In the transverse channel the rho meson is, especially at non-zero momentum, completely washed out and can in the presence of nuclear matter no longer be viewed as a resonant excitation of the vacuum. Instead, our model shows a continuum of possible excitations with the quantum numbers of a transversely polarized rho. in the longitudinal channel, however, the rho retains its resonant character in our calculation. As a consequence of the self-consistent treatment we also find a strong enhancement of the widths o| the included nucleon resonances in medium. (~ 1998 Elsevier Science B.V.