0000000000400256
AUTHOR
Rafael C. Carrasco
Coherent (γ, π0) photoproduction in a local approximation to the delta-hole model
Abstract We develop a local approximation to the Δh model for coherent π 0 photoproduction in nuclei which allows one to perform reliable calculations in heavy nuclei where the traditional Δh approach is technically unfeasible. We evaluate the cross section in different nuclei and compare our results with available data in 12 C.
Photon and Pion Nuclear Absorption Mechanisms
Using a microscopical many body approach to pion and photonuclear reactions we study the mechanisms of pion and photon absorptions with emphasis on the number of nucleons involved in the genuine absorption process.
Deeply bound pionic atoms with resonant Compton scattering
Abstract We study the contribution to ordinary Compton nuclear scattering of the resonant channel γ + A → (A′ π − ) → γ + A with the π − bound in the nucleus. We show that the interference of this resonant channel with background amplitudes produces significant peaks in the elastic backward differential cross section as a function of the incoming photon energy for light and medium-size nuclei. We also find that for light nuclei the signals in forward Compton scattering or in the total photonuclear cross section are big enough to be observed, provided there is a good resolution in the photon beam. The reaction is particularly suited to find deeply bound pionic states in medium-size nuclei, o…
Photonuclear reactions at intermediate energies
Starting from basic couplings of the photons to mesons, nucleons and isobars a microscopic manybody theory is developped which allows one to evaluate different photonuclear reactions at intermediate energies. The theory is applied to obtain the total photonuclear cross section and the separation between γ absorption and (γ, π) reaction channels.
Inclusive eta photoproduction in nuclei.
A local model for the nuclear medium modifications to the photoproduction of \ensuremath{\eta} mesons through the ${\mathit{N}}^{\mathrm{*}}$(1535) resonance is applied to the study of the inclusive reaction in medium and heavy nuclei. The use of effective Lagrangians and many body quantum theory allows one to incorporate the nuclear decay channels of the ${\mathit{N}}^{\mathrm{*}}$ involving a pair of nucleons and Fermi sea effects. Also the \ensuremath{\eta}N final state interaction is considered, taking into account the nuclear renormalization of the \ensuremath{\eta}N scattering cross section, and assuming a classical propagation between collisions. The results show a depletion and broa…