A new probe to study symmetry energy at low density by deuteron breakup reaction

TL;DR

This paper proposes a novel method using polarized deuteron breakup reactions to more effectively study the symmetry energy at low densities, overcoming previous experimental limitations.

Contribution

It introduces a new probe based on elastic scattering angle differences from deuteron breakup, providing a cleaner and more effective way to constrain symmetry energy.

Findings

Elastic scattering angle distributions of proton and neutron are similar to individual scattering results.

The difference in scattering angles serves as a sensitive probe for symmetry energy.

The method improves the precision of symmetry energy measurements at subsaturation densities.

Abstract

The reactions of nucleon and polarized deuteron scattered off a heavy target at large impact parameter with intermediate energies have been investigated by using the improved quantum molecular dynamics model. It is found that, due to the difference effect of isovector potential on proton and neutron, there is a significant difference between the angle distribution of elastic scattering protons and neutrons. To overcome the lack of monochromatic neutron beam, the reaction of polarized deuteron peripherally scattered off the heavy target is used to replace the reaction of individual proton and neutron scattered off heavy target to study the isospin effect. It is found that the distributions of elastic scattering angle of proton and neutron originating from the breakup of deuteron are very similar to the results of the individual proton- and neutron-induced reaction. A new probe more effective and more clean, namely the difference between elastic scattering angle of proton and neutron originating from the breakup of polarized deuteron, is promoted to constrain the symmetry energy at subsaturation density.