Seminarium: Attila Krasznahorkay, Institute for Nuclear Research (MTA-Atomki), Debrecen, Hungary
|Wanneer:||di 10-12-2013 om 11:00|
Titel: Neutron-skin thickness and symmetry-energy constraints from the study of the anti-analog giant dipole resonance
Abstract: The 208Pb(p,nγp)207Pb reaction at a beam energy of 30 MeV has been used to excite the anti-analog of the giant dipole resonance (AGDR) and to measure its γ-decay to the isobaric analog state in coincidence with proton decay of IAS. The energy of the transition has also been calculated with the self-consistent relativistic random-phase approximation (RRPA), and found to be linearly correlated to the predicted value of the neutron-skin thickness (Rpn). By comparing the theoretical results with the measured transition energy, the value of 0.190±0.028 fm has been determined for Rpn of 208Pb, in agreement with previous experimental results. The AGDR excitation energy has also been used to calculate the symmetry energy at saturation (J = 32.7±0.6 MeV) and the slope of the symmetry energy (L = 49.7±4.4 MeV), resulting in more stringent constraints than most of the previous studies.