Angular momentum misalignment in deep inelastic processes and angular distribution of sequentially emitted particles and gamma rays

Abstract

The angular momentum misalignment for fragments produced in deep inelastic scattering is discussed in terms of the thermal excitation of angular-momentum-bearing modes in the intermediate complex.Analytical expressions for the in-and out-of-plane angular distributions are ootained for sequentially emitted particles and fission fragments. The angular momentum dependence of the ratio between particle and neutron decay width is explicitly treated and found to be quite important. Similarly angular distributions are obtained both for dipole and quadrupole gamma decay. The theoretical results are compared with experimental angular distributions of sequential fission fragments, sequential alphas and gamma rays and a good agreement is found.

Particle and light fragment emission in peripheral heavy ion collisions at Fermi energies

“…However, the shape of the experimental distribution is not very sensitive to the spin value. In fact, as verified with Monte Carlo simulations, even in case of an initial strong alignment of the spin perpendicular to the reaction plane, the anisotropy of the experimental angular distribution is reduced -with respect to the theoretical one [31,32] -by the misalignment of the spin (caused by the particle evaporation) and by the fluctuations of the reconstructed reaction plane. Both effects increase with increasing number of particles emitted along the evaporation chain and hence with increasing TKEL.…”

Alpha-particle emission from the reaction 1354 MeVHo165+TaSobotka1, McDonald2, Wozniak3 et al. 1983Phys. Rev. C7020View full textAdd to dashboardCite

“…Perhaps the most important result from the present study is that the general formalism described in Ref. 23 for the angular distribution of sequentially emitted particles, when coupled with input parameters extracted from the experimental data, does an admirable job of reproducing the out-of-plane a-particle distribution. In-plane laboratory a-particle energy spectra.…”

Sequential fission angular distributions from mass-asymmetric heavy-ion reactions

“…Contours of the coincidence cross section for detecting a sequential fission fragment are shown as a function of projectile-like fragment charge, 23 and total kinetic energy (TKE) for gold, (A), and uranium, (8), targets. Random coincidences are seen in part (A) at the highest probability (or quasielastic events.…”