Dissipative reactions with intermediate-energy beams -- a novel approach to populate complex-structure states in rare isotopes

TL;DR

This paper introduces a new method using highly dissipative inelastic scattering at intermediate energies to populate complex multi-particle states in rare isotopes, enabling nuclear-structure studies of previously inaccessible configurations.

Contribution

It demonstrates a novel approach to excite complex multi-particle states in rare isotopes through highly dissipative reactions, expanding the experimental toolkit beyond traditional surface-grazing methods.

Findings

Observation of negative-parity, complex-structure states in 38Ca

Rearrangement of multiple nucleons in energetic collisions

Potential to study complex nuclear configurations previously out of reach

Abstract

A novel pathway for the formation of multi-particle-multi-hole (np-mh) excited states in rare isotopes is reported from highly energy- and momentum-dissipative inelastic-scattering events measured in reactions of an intermediate-energy beam of 38Ca on a Be target. The negative-parity,complex-structure final states in 38Ca were observed following the in-beam gamma-ray spectroscopy of events in the 9Be(38Ca,38Ca+gamma)X reaction in which the scattered projectile lost longitudinal momentum of order p = 700 MeV/c. The characteristics of the observed final states are discussed and found to be consistent with the formation of excited states involving the rearrangement of multiple nucleons in a single, highly-energetic projectile-target collision. Unlike the far-less dissipative, surface-grazing reactions usually exploited for the in-beam gamma-ray spectroscopy of rare isotopes, these more energetic collisions appear to offer a practical pathway to nuclear-structure studies of more complex multi-particle configurations in rare isotopes - final states conventionally thought to be out of reach with high-luminosity fast-beam-induced reactions.