54770513
O18+Pd110: Measurements and realistic coupled-channel analysis in a transitional region
The inelastic, two-neutron and \ensuremath{\alpha} transfer and quasielastic cross sections for the $^{18}\mathrm{O}+^{110}\mathrm{Pd}$ system have been measured in the near barrier region (40 MeV $\ensuremath{\leqslant}{E}_{\mathrm{lab}}\ensuremath{\leqslant}58$ MeV). The experiments were performed in the S\~ao Paulo Pelletron laboratory. Coupled-channel analysis of the experimental data was performed using the S\~ao Paulo potential as a microscopic bare interaction. In the calculations, low-lying inelastic excitations, one- and two-neutron and \ensuremath{\alpha} transfers to the target were considered as the main couplings, with no extra surface absorption. The agreement between the theoretical results and the experimental data is good. The role played by the coupled channels is very different in comparison with similar data analyses for the closed-shell region around $^{58}\mathrm{Ni}$.
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.}
120551728
Magnetic dipole and electric quadrupole rotational structures and chirality in Rh-105
The $^{105}\mathrm{Rh}$ nucleus has been studied with the $^{100}\mathrm{Mo}(^{11}\mathrm{B},\ensuremath{\alpha}2n\ensuremath{\gamma})$ reaction at $43\phantom{\rule{0.3em}{0ex}}\text{MeV}$ incident energy. A rich variety of structures was observed at high and low spins, using $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}\text{\ensuremath{-}}t$ and $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}\text{\ensuremath{-}}\mathit{particle}$ coincidences and directional correlation ratios. A $\ensuremath{\gamma}$-vibrational band was observed for the first time in this nucleus. A new structure based on the intruder $1∕{2}^{+}$[431] proton orbital was identified. Four magnetic dipole bands have also been observed at high spin, three of which have negative parity and have similar characteristics: they are very regular in energy spacing, presenting nearly constant alignments and large values of $B(M1)∕B(E2)$ ratios. Two of them are nearly degenerate in excitation energy and could be chiral partners. The $\ensuremath{\pi}{g}_{9∕2}\ensuremath{\bigotimes}\ensuremath{\nu}{h}_{11∕2}({g}_{7∕2},{d}_{5∕2})$ configuration is tentatively assigned for these bands, with the angular momenta of the proton and neutron intruders and the collective angular momentum aligning along the three perpendicular axes of the triaxial core, as predicted by tilted axis cranking calculations.
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.
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.
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.
125114851
Vaccum polarization effects on quasinormal modes in electrically charged black hole spacetimes