# $\gamma$-ray Strength Function for Barium Isotopes

## TL;DR

This study measures photoneutron cross sections for $^{137}$Ba and $^{138}$Ba to constrain the gamma-ray strength function, improving understanding of neutron capture processes relevant to barium nucleosynthesis.

## Contribution

It provides experimentally constrained gamma-ray strength functions for barium isotopes using laser Compton-scattering data and theoretical modeling, advancing nuclear astrophysics models.

## Key findings

- Photoneutron cross sections measured below two-neutron threshold.
- Constrained gamma-ray strength functions using experimental data and theoretical models.
- Discussed implications for s-process nucleosynthesis of barium.

## Abstract

Photoneutron cross sections were measured for $^{137}$Ba and $^{138}$Ba at energies below two-neutron threshold using quasi-monochromatic $\gamma$-ray beams produced in laser Compton-scattering at the NewSUBARU synchrotron radiation facility. The photoneutron data are used to constrain the $\gamma$-ray strength function on the basis of the Hartree-Fock-Bogolyubov plus quasi-particle random phase approximation using the Gogny D1M interaction. Supplementing the experimentally constrained $\gamma$-ray strength function with the zero-limit E1 and M1 contributions which are unique to the deexcitation mode, we discuss radiative neutron capture cross sections relevant to the s-process nucleosynthesis of barium isotopes in the vicinity of the neutron magic number 82.