Self consistent and covariant propagation of pions, nucleon and isobar resonances in cold nuclear matter

✍ Scribed by C.L. Korpa; M.F.M. Lutz

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 607 KB
• Volume: 742
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2004.06.031

✦ Synopsis

We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the pion-nucleon scattering phase shifts and a set of Migdal parameters describing important short range correlation effects. We do not observe significant softening of pion modes if we insist on reasonable isobar resonance properties but predict a considerable broadening of the N(1440) and N(1520) resonances in nuclear matter. Contrasted results are obtained for the s-wave N(1535) and N(1650) resonances which are affected by a nuclear environment very little. The properties of slowly moving isobar's in nuclear matter are found to depend very sensitively on a soft form factor in the πNN vertex, which is not controlled by the πN scattering data.