The Delta(1232) at RHIC

Abstract

We investigate properties of the Delta(1232) and nucleon spectral functions at finite temperature and baryon density within a hadronic model. The medium modifications of the Delta consist of a renormalization of its pion-nucleon cloud and resonant pi-Delta scattering. Underlying coupling constants and form factors are determined by the elastic π-N scattering phase shift in the isobar channel, as well as empirical partial decay widths of excited baryon resonances. For cold nuclear matter the model provides reasonable agreement with photoabsorption data on nuclei in the Delta-resonance region. In hot hadronic matter typical for late stages of central Au-Au collisions at RHIC we find the Delta-spectral function to be broadened by $\sim$65 MeV together with a slight upward mass shift of 5-10 MeV, in qualitative agreement with preliminary data from the STAR collaboration.

7 pages, 4 figures, Talk given at the Hot Quarks 2004 Workshop, Taos,NM, July 18-24 2004, v3: typos corrected

References in corpus (14)

• Low-mass e+e- pair production in 158 A GeV Pb-Au collisions at the CERN SPS, its dependence on multiplicity and transverse momentum
• Enhanced Production of Low-Mass Electron Pairs in 40 AGeV Pb-Au Collisions at the CERN SPS
• Renormalization of Self-consistent Approximation schemes Finite Temperature II: Applications to the Sunset Diagram
• Thermodynamics of Delta resonances
• Modifications of the Rho Meson from the Virtual Pion Cloud in Hot and Dense Matter
• Interferometry of Direct Photons in Central 280Pb+208Pb Collisions at 158A GeV
• A Microscopic Calculation of Photoabsorption Cross Sections on Protons and Nuclei
• The role of Delta(1700) excitation and rho production in double pion photoproduction
• Hadro-Chemistry and Evolution of (Anti-) Baryon Densities at RHIC
• Charged pions from Ni on Ni collisions between 1 and 2 AGeV
• Resonance Production
• Thermal Properties of a Hot Pion Gas beyond the Quasiparticle Approximation
• Self consistent and covariant propagation of pions, nucleon and isobar resonances in cold nuclear matter
• Thermal Photons in Strong Interactions

Cited by in corpus (3)

• What do we learn from Resonance Production in Heavy Ion Collisions?
• The Vector Probe in Heavy-Ion Reactions
• A study of the elastic $\pi N$ scattering at finite baryon density