Spin transport in intermediate-energy heavy-ion collisions as a probe of in-medium spin-orbit interactions

TL;DR

This paper investigates how spin-dependent collective flows in intermediate-energy heavy-ion collisions can reveal properties of in-medium nuclear spin-orbit interactions, using a specialized transport model and analyzing various collision conditions.

Contribution

It introduces a spin- and isospin-dependent transport model to study spin splittings in collective flows, providing new insights into in-medium nuclear spin-orbit interactions.

Findings

Largest spin splittings occur in peripheral Au+Au collisions at 100-200 MeV/nucleon.

Spin effects are significant even in smaller systems for high transverse momentum nucleons.

Collective flows of light clusters with different spins are also affected by spin-orbit interactions.

Abstract

The spin up-down splitting of collective flows in intermediate-energy heavy-ion collisions as a result of the nuclear spin-orbit interaction is investigated within a spin- and isospin-dependent Boltzmann-Uehing-Uhlenbeck transport model SIBUU12. Using a Skyrme-type spin-orbit coupling quadratic in momentum, we found that the spin splittings of the directed flow and elliptic flow are largest in peripheral Au+Au collisions at beam energies of about 100-200 MeV/nucleon, and the effect is considerable even in smaller systems especially for nucleons with high transverse momenta. The collective flows of light clusters of different spin states are also investigated using an improved dynamical coalescence model with spin. Our study can be important in understanding the properties of in-medium nuclear spin-orbit interactions once the spin-dependent observables proposed in this work can be measured.