Problems of experimental determination of parameters of nucleus and applicability of the Bohr-Mottelson hypothesis

TL;DR

This paper investigates the challenges in accurately determining nuclear parameters like level density and radiative widths, highlighting limitations of the Bohr-Mottelson hypothesis in light spherical nuclei based on experimental data analysis.

Contribution

It critically examines the applicability of the Bohr-Mottelson hypothesis and demonstrates the limitations of current methods in estimating nuclear parameters from experimental data.

Findings

Population data for 51V and 57Fe levels cannot be reproduced assuming independence of radiative widths.

Current spectrum analysis methods may not reliably estimate level densities and radiative widths.

The assumption of independence of partial radiative widths is invalid below certain energy thresholds.

Abstract

Population of a number of excited levels of 51V and 57Fe has been determined from the data of the ENDSF file up to the excitation energy of about 7 and 5.2 MeV, respectively. It cannot be reproduced in the region of their maximal energies in the framework of assumption on the independence of partial radiative widths on the structure of decaying level and excited one, at least, lower than 0.5Bn. Therefore, it is impossible to estimate the actual degree of reliability of data on the level density and radiative widths of cascade gamma-transitions in light spherical nuclei obtained from the spectrum analysis of nuclear reactions, which do not take into account this circumstance.