120192622
An imaginary potential with universal normalization for dissipative processes in heavy-ion reactions
Abstract In this work we present new coupled channel calculations with the Sao Paulo potential (SPP) as the bare interaction, and an imaginary potential with system and energy independent normalization that has been developed to take into account dissipative processes in heavy-ion reactions. This imaginary potential is based on high-energy nucleon interaction in nuclear medium. Our theoretical predictions for energies up to ≈ 100 MeV / nucleon agree very well with the experimental data for the p , n + nucleus , 16O + 27Al, 16O + 60Ni, 58Ni + 124Sn, and weakly bound projectile 7Li + 120Sn systems.
1175616
Multiple dipole bands at prolate shapes in 136Nd and their description through the projected shell model.
Five bands dominated by strong {ital M}1 transitions have been observed in the {sup 136}Nd nucleus. Two of them consist of only dipole transitions, whereas the other three show also weak crossover transitions. The bands have been firmly connected to lower-spin states. Theoretical calculations using the projected shell model suggest quasiparticle configurations involving two protons and two neutrons for the four lowest-lying bands. {copyright} {ital 1996 The American Physical Society.}
118964632
ONSET OF COLLECTIVITY IN NEUTRON-DEFICIENT PO-196,PO-198
We have studied via in-beam gamma-ray spectroscopy Po-196 and Po-198, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The ratios of yrast state energi ...
120421643
Observation of double electron-positron pair production by γ rays reexamined
An experiment was conducted to observe triple- and quadruple-escape peaks, at a photon energy equal to 6.128 MeV, in the spectra recorded with a high-purity Ge detector working in coincidence with six bismuth germanate detectors. The peak intensities may be explained having recourse to only the bremsstrahlung cascade process of consecutive electron-positron pair creation; i.e., the contribution of simultaneous double pair formation (and other cascade effects) is much smaller. The experimental peak areas are in reasonably good agreement with those predicted by Monte Carlo simulations done with the general-purpose radiation-transport code PENELOPE.
123191123
Nuclear rainbow in the 16O + 27AL system: The role of couplings at energies far above the barrier
Abstract High precision elastic and inelastic angular distributions have been measured for the 16 O +  27 Al system at a beam energy of 100 MeV. The data analysis confirms a rainbow formation as already predicted by parameter-free Coupled Channel calculations. It also helps to reveal the crucial role of inelastic couplings in the rainbow formation for heavier systems even at energies far above the Coulomb barrier. This feature, well known in atomic/molecular scattering, is experimentally studied for the first time in Nuclear Physics.
29454387
Lifetimes of the decay from superdeformed to normal deformed in 135Nd.
Lifetimes of low-spin members of the superdeformed band in [sup 135]Nd have been determined by the Doppler-shift recoil-distance method. We find a quadrupole moment of 7.2[sub [minus]1.5][sup +1.2] b for the 677 keV (37/2- 33) / 2 transition in the band, confirming the large deformation previously measured by the Doppler-shift attenuation method. However, the quadrupole moment for the 620 keV transition deexciting the 3.324 MeV (25/2) state at the bottom of the band is much smaller. We conclude that the superdeformed potential-energy minimum disappears or the band drastically changes character at this point which causes the sudden depopulation.
118686912
Stability analysis and area spectrum of three-dimensional Lifshitz black holes
In this work, we probe the stability of a $z=3$ three-dimensional Lifshitz black hole by using scalar and spinorial perturbations. We found an analytical expression for the quasinormal frequencies of the scalar probe field, which perfectly agree with the behavior of the quasinormal modes obtained numerically. The results for the numerical analysis of the spinorial perturbations reinforce the conclusion of the scalar analysis, i.e., the model is stable under scalar and spinor perturbations. As an application we found the area spectrum of the Lifshitz black hole, which turns out to be equally spaced.