Study of giant dipole resonance in hot rotating light mass nucleus P-31

Abstract

An exclusive systematic study of the giant dipole resonance (GDR) parameters has been performed in very light mass nucleus (31)Pin the temperature range of similar to 0.8-2.1 MeV and average angular momentum of similar to 11-16 (h) over bar. The high-energy gamma rays from the decay of the GDR, evaporated neutrons and gamma-ray multiplicities have been measured. The angular distribution of high-energy gamma rays has also been measured at E-beam= 42 MeV. The GDR parameters, nuclear level density parameter and nuclear temperature were precisely determined by simultaneous statistical model analysis of high-energy gamma ray and evaporated neutron spectra. It is observed that the measured width remains roughly constant up to a temperature of similar to 1.6 MeV. Moreover, the thermal pairing plays no role in describing the GDR width in this open-shell light nucleus at the above-mentioned temperatures and angular momenta. The present measurements provide an excellent platform to extend the applicability of the existing theoretical models down to the very light mass nuclei. Show more