Search for $\alpha$-cluster states in even-even Cr isotopes

TL;DR

This study investigates alpha-cluster states in even-even Cr isotopes using a local potential model, successfully describing experimental spectra and revealing strong alpha-cluster characteristics in the ground state bands.

Contribution

It introduces a local alpha + core potential model to analyze alpha clustering in Cr isotopes, providing good agreement with experimental data without effective charges.

Findings

Successful reproduction of experimental spectra for $^{46}$Cr and $^{54}$Cr.

Identification of strong alpha-cluster character in ground state bands.

Consistent potential parameters with previous alpha scattering studies.

Abstract

The $\alpha + \mathrm{core}$ structure is investigated in even-even Cr isotopes from the viewpoint of the local potential model. The comparison of $Q_{\alpha}/A$ values for even-even Cr isotopes and even-even $A = 46,54,56,58$ isobars indicates that $^{46}$Cr and $^{54}$Cr are the most favorable even-even Cr isotopes for $\alpha$-clustering. The ground state bands of the two Cr isotopes are calculated through a local $\alpha + \mathrm{core}$ potential with two variable parameters. The calculated spectra give a very good description of most experimental $^{46}$Cr and $^{54}$Cr levels. The reduced $\alpha $-widths, rms intercluster separations and $B(E2)$ transition rates are determined for the ground state bands. The calculations reproduce the order of magnitude of the available experimental $B(E2)$ values without using effective charges and indicate that the first members of the ground state bands present a stronger $\alpha$-cluster character. The volume integral per nucleon pair and rms radius obtained for the $\alpha+^{50}$Ti potential are consistent with those reported previously in the analysis of $\alpha$ elastic scattering on $^{50}$Ti.