We analyze the role of meson exchange currents MECs in photon- and electron-induced one nucleon emission reactions in a fully relativistic model. The relativistic mean-field theory is used for the bound state and the Pauli reduction for the scattering state. Direct one-body and exchange two-body terms in the nuclear current are considered. Results for the 12C(g ,p) and 16O(g ,p) differential cross sections and photon asymmetries are displayed in an energy range between 60 and 196 MeV. The two-body seagull current affects the cross section less than in nonrelativistic analyses. In the case of the 16O(g ,n) differential cross section, MECeffects are large but not sufficient to reproduce the data. MECs have a small effect on (e,e'p) calculations.
Meson Exchange Currents in a Relativistic Model for Electromagnetic One Nucleon Emission
MEUCCI, ANDREA;GIUSTI, CARLOTTA;PACATI, FRANCODAVIDE
2002-01-01
Abstract
We analyze the role of meson exchange currents MECs in photon- and electron-induced one nucleon emission reactions in a fully relativistic model. The relativistic mean-field theory is used for the bound state and the Pauli reduction for the scattering state. Direct one-body and exchange two-body terms in the nuclear current are considered. Results for the 12C(g ,p) and 16O(g ,p) differential cross sections and photon asymmetries are displayed in an energy range between 60 and 196 MeV. The two-body seagull current affects the cross section less than in nonrelativistic analyses. In the case of the 16O(g ,n) differential cross section, MECeffects are large but not sufficient to reproduce the data. MECs have a small effect on (e,e'p) calculations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
