βand isomeric decay ofV64

Abstract

Background: Collectivity has been inferred in $^{64}\mathrm{Cr}$ based on measurements of the excitation energy of the first excited ${2}^{+}$ state and $B(E2;{2}_{1}^{+}\ensuremath{\rightarrow}\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}{0}_{1}^{+})$ value. However, the energy of the ${2}_{1}^{+}$ state in $^{64}\mathrm{Cr}$ is not precisely known.Purpose: The objective was to precisely determine the energy of the ${2}_{1}^{+}\ensuremath{\rightarrow}{0}_{1}^{+}$ transition in $^{64}\mathrm{Cr}$ following the $\ensuremath{\beta}$ decay of $^{64}\mathrm{V}$.Method: $^{64}\mathrm{V}$ ions were produced by projectile fragmentation at the National Superconducting Cyclotron Laboratory and stopped in a double-sided Si strip detector. $^{64}\mathrm{V}$ isomeric and $\ensuremath{\beta}$-delayed $\ensuremath{\gamma}$ rays were detected in an ancillary array of high-purity Ge detectors in order to determine the energies of excited states in $^{64}\mathrm{V}$ and $^{64}\mathrm{Cr}$.Results: The first excited ${2}^{+}$ state in $^{64}\mathrm{Cr}$ was populated following the $\ensuremath{\beta}$ decay of $^{64}\mathrm{V}$, and an energy of 430(2) keV was determined. Additionally, an isomeric state in $^{64}\mathrm{V}$ with an energy of 81.0(7) keV and a half-life less than 1 $\ensuremath{\mu}$s was discovered.Conclusion: The excitation energy of the ${2}_{1}^{+}$ state in $^{64}\mathrm{Cr}$ has been precisely determined and an isomeric state is identified in $^{64}\mathrm{V}$ for the first time.