# $^{137,138,139}$La($n$, $\gamma$) cross sections constrained with statistical decay properties of $^{138,139,140}$La nuclei

## TL;DR

This study measures nuclear level densities and gamma-ray strength functions of La isotopes to accurately calculate neutron capture cross sections relevant for astrophysical processes.

## Contribution

It provides new experimental data on level densities and gamma-ray strengths of La isotopes, improving cross section calculations for astrophysical nucleosynthesis.

## Key findings

- Good agreement with previous measurements of $^{139}$La(n,γ) cross sections
- Observation of low-energy enhancement in gamma-ray strength functions
- Enhanced understanding of nuclear properties in the A~140 region

## Abstract

The nuclear level densities and $\gamma$-ray strength functions of $^{138,139,140}$La were measured using the $^{139}$La($^{3}$He, $\alpha$), $^{139}$La($^{3}$He, $^{3}$He$^\prime$) and $^{139}$La(d, p) reactions. The particle-$\gamma$ coincidences were recorded with the silicon particle telescope (SiRi) and NaI(Tl) (CACTUS) arrays. In the context of these experimental results, the low-energy enhancement in the A$\sim$140 region is discussed. The $^{137,138,139}$La($n, \gamma)$ cross sections were calculated at $s$- and $p$-process temperatures using the experimentally measured nuclear level densities and $\gamma$-ray strength functions. Good agreement is found between $^{139}$La($n, \gamma)$ calculated cross sections and previous measurements.