Off-shell pions in the BUU transport theory
نویسندگان
چکیده
Due to the large resonance πN scattering cross section a pion with momentum ∼ 0.3 GeV/c acquires a width in nuclear matter. The pion spectral function in nuclear matter is, therefore, different from the vacuum one. The present work is the first attempt to include the pion spectral function into the BUU transport theory. We have calculated the pion polarization function Πc(k) in isospin symmetric nuclear matter applying the ∆-hole model (c.f. [1, 2]) with the relativistic nucleon and delta propagators [3]. The pion spectral function is defined as follows: Aπ(k) ≡ − 1 π ImG(k) , (1)
منابع مشابه
Low-energy pions in nuclear matter and ππ photoproduction within a BUU transport model
In the present paper we investigate a method to describe lowenergy scattering events of pions and nuclei within a Boltzmann-UehlingUhlenbeck (BUU) transport model. Implementing different scenarios of medium modifications, we studied the mean free path of pions in nuclear matter at low momenta and compared pion absorption simulations to data. Pursuing these studies we have shown, that also in a ...
متن کامل- th / 0 60 30 03 v 2 1 S ep 2 00 6 Low - energy pions in nuclear matter and ππ photoproduction within a BUU transport model
A description of low-energy scattering of pions and nuclei within a BUU transport model is presented. Implementing different scenarios of medium modifications, the mean free path of pions in nuclear matter at low momenta and pion absorption reactions on nuclei have been studied and compared to data and to results obtained via quantum mechanical scattering theory. We show that even in a regime o...
متن کاملOff - shell effects on particle production ∗
We investigate the observable effects of off-shell propagation of nucleons in heavy-ion collisions at SIS energies. Within a semi-classical BUU transport model we find a strong enhancement of subthreshold particle production when off-shell nucleons are propagated. During the past 15 years semi-classical transport models have extensively and quite successfully been applied to the description of ...
متن کاملOff-shell electromagnetic form factors of pions and kaons in chiral perturbation theory.
The off–shell electromagnetic vertex of a (pseudo–) scalar particle contains, in general, two form factors F and G which depend, in addition to the squared momentum transfer, on the invariant masses associated with the initial and final legs of the vertex. Chiral perturbation theory to one loop is used to calculate the off–shell form factors of pions and kaons. The formalism of Gasser and Leutw...
متن کاملElectroproduction of hadrons on nuclei at GeV energies
We investigate coherence length effects and hadron attenuation in lepton scattering off nuclei in the kinematic regime of the HERMES experiment. The elementary electron-nucleon interaction is described within the event generator PYTHIA while a full coupled-channel treatment of the final state interactions is included by means of a BUU transport model. The results of our calculations are in good...
متن کامل