A Search for $0^{+}$ States in ${}^{50}$Cr: Implications for the Superallowed $\beta$-decay of ${}^{50}$Mn

Abstract

A ${}^{52}$Cr$(p,t)$${}^{50}$Cr two-neutron pickup reaction was performed using the Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium in Garching, Germany. Excited states in ${}^{50}$Cr were observed up to an excitation energy of 5.3 MeV. Despite significantly increased sensitivity and resolution over previous work, no evidence of the previously assigned first excited $0^{+}$ state was found. As a result, the $0_2^{+}$ state is reassigned at an excitation energy of $E_x=3895.0(5)$ keV in ${}^{50}$Cr. This reassignment directly impacts direct searches for a non-analogue Fermi ${\beta }^{+}$ decay branch in ${}^{50}$Mn. These results also show better systematic agreement with the theoretical predictions for the $0^{+}$ state spectrum in ${}^{50}$Cr using the same formalism as the isospin-symmetry-breaking correction calculations for superallowed nuclei. The experimental data are also compared to $ab$-$initio$ shell-model predictions using the IM-SRG formalism based on $NN$ and $3N$ forces from chiral-EFT in the $pf$-shell for the first time.

Accepted for Publication in Physical Review C as a Rapid Communication

References in corpus (11)

• Chiral effective field theory and nuclear forces
• Accurate nuclear radii and binding energies from a chiral interaction
• Local three-nucleon interaction from chiral effective field theory
• An improved calculation of the isospin-symmetry-breaking corrections to superallowed Fermi beta decay
• In-Medium Similarity Renormalization Group for Open-Shell Nuclei
• Isospin corrections for superallowed Fermi beta decay in self-consistent relativistic random phase approximation approaches
• Comparative tests of isospin-symmetry-breaking corrections to superallowed 0+-to-0+ nuclear beta decay
• Isospin-symmetry-breaking corrections to superallowed Fermi beta decay: Formalism and schematic models
• Coulomb corrections to superallowed beta decay in nuclei
• Isospin mixing in nuclei within the nuclear density functional theory
• Microscopic calculations of isospin-breaking corrections to superallowed beta-decay

Cited by in corpus (1)

• High-precision $Q_{EC}$-value measurement of the superallowed ${\beta }^{+}$ emitter ${}^{22}$Mg and an evaluation of the $A=22$ isobaric triplet