SAIP2026

Experimental Test of the Generalized Brink-Axel Hypothesis and Thermodynamic Properties of $^{140}$La

8 Jul 2026, 11:20

20m

Lecture Hall GH2 (University of the Western Cape)

Oral Presentation Track B - Nuclear, Particle and Radiation Physics Nuclear, Particle and Radiation Physics -1

Speaker

Ayabulela Tsewu

Description

The generalized Brink-Axel (gBA) hypothesis is central to $\gamma$-ray strength function ($\gamma$SF) extraction and nucleosynthesis reaction network calculations, yet remains insufficiently tested. We present the first experimental test of the gBA hypothesis in the mid-mass odd-odd nucleus $^{140}$La. The results confirm the validity of the gBA for this nucleus, supporting its use in both experimental methods and astrophysical applications.
We further investigate the thermodynamic properties of $^{140}$La to probe nuclear statistical behavior in odd-odd systems, where clear signatures of Cooper pair breaking are not expected, and new excitation modes have been proposed. We report the first experimental results on the entropy, nuclear temperature, and heat capacity of $^{140}$La.
The entropy and nuclear temperature follow established systematics, while the heat capacity exhibits signatures of pair breaking. No evidence for new excitation modes is observed.