Microscopic structure of charge-exchange spin-isospin modes through decay measurements

The study of particle decay of charge-exchange giant resonances (CEGR) furnishes information on their microscopic structure. Furthermore, gamma decay of CEGR call help to unravel their structure. For example, the gamma-decay of the Gamow-Teller (GT) resonance to the isobaric analogue state (IAS) points to a possible method to study quenching of GT strength. The study of gamma-decay of the spin-flip dipole resonance (SDR) to GT and low-lying states will possibly allow to disentangle the different spin components. These aspects will be discussed in the light of recent (He-3,t) experiments at E(He-3) = 450 MeV and theta = 0 degrees performed to study the proton decay of CEGR in Bi-208 and N-12 and the gamma decay of the GT resonance, IAS and SDR in Nb-90.</p

Microscopic structure of charge-exchange spin-isospin modes through decay measurements

The study of particle decay of charge-exchange giant resonances (CEGR) furnishes information on their microscopic structure. Furthermore, gamma decay of CEGR call help to unravel their structure. For example, the gamma-decay of the Gamow-Teller (GT) resonance to the isobaric analogue state (IAS) points to a possible method to study quenching of GT strength. The study of gamma-decay of the spin-flip dipole resonance (SDR) to GT and low-lying states will possibly allow to disentangle the different spin components. These aspects will be discussed in the light of recent (He-3,t) experiments at E(He-3) = 450 MeV and theta = 0 degrees performed to study the proton decay of CEGR in Bi-208 and N-12 and the gamma decay of the GT resonance, IAS and SDR in Nb-90

Microscopic structure of charge-exchange spin-isospin modes through decay measurements

The study of particle decay of charge-exchange giant resonances (CEGR) furnishes information on their microscopic structure. Furthermore, gamma decay of CEGR call help to unravel their structure. For example, the gamma-decay of the Gamow-Teller (GT) resonance to the isobaric analogue state (IAS) points to a possible method to study quenching of GT strength. The study of gamma-decay of the spin-flip dipole resonance (SDR) to GT and low-lying states will possibly allow to disentangle the different spin components. These aspects will be discussed in the light of recent (He-3,t) experiments at E(He-3) = 450 MeV and theta = 0 degrees performed to study the proton decay of CEGR in Bi-208 and N-12 and the gamma decay of the GT resonance, IAS and SDR in Nb-90

Isoscalar dipole strength in ^{208}_{82}Pb_{126}: the spurious mode and the strength in the continuum

Isoscalar dipole (compression) mode is studied first using schematic harmonic-oscillator model and, then, the self-consistent Hartree-Fock (HF) and random phase approximation (RPA) solved in coordinate space. Taking ^{208}Pb and the SkM* interaction as a numerical example, the spurious component and the strength in the continuum are carefully examined using the sum rules. It is pointed out that in the continuum calculation one has to use an extremely fine radial mesh in HF and RPA in order to separate, with good accuracy, the spurious component from intrinsic excitations.Comment: 19 pages, 2 figure

A Study of the (3-He,t) Charge-Exchange Reaction at E(3-He) = 200 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Atomic Charge Exchange Between Fast Singly- and Doubly-Ionized Helium Ions in Targets from Carbon to Bismuth at β = 0.36

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Viscosity and fission time scale of^{156}Dy

In the fusion-fission reaction Ar-40+Cd-116-->Dy-156-->fission, performed at beam energies E(b) = 216 MeV and 238 MeV, gamma rays were measured in coincidence with fission fragments. The gamma-ray spectra are interpreted using a modified version of the statistical-model code CASCADE. From a comparison of the experimental and calculated spectra it is deduced that the nuclear viscosity is in the range 0.01 <gamma <4. The extracted fission time scale is of the order of 10(-19) s