Puzzling $B(E2;0^{+}\to 2^{+})$ strength in the proton dripline nucleus ${}^{36}$Ca

Abstract

Recent measurements of the $E2$ transition rate from the ground state to the first 2${}^{+}$ excited state of the proton dripline nucleus ${}^{36}$Ca show an unusual pattern when compared to its isotopic neighbor ${}^{38}$Ca: despite having a higher $E_x(2_1^{+})$ excitation energy, the $B(E2;0_1^{+}\to 2_1^{+})$ rate in ${}^{36}$Ca is larger. The question that naturally arises is to what extent this observation can be attributed to the unbound character of the $2_1^{+}$ state. To understand the influence of the continuum space on the low-energy properties of ${}^{36}$Ca, we carried out Gamow shell model calculations that can account for the continuum coupling effects associated with the occupation of unbound $fp$ shells. We found that in the threshold $2^{+}$ state, ${}^{36}$Ca is spatially diffused, which impacts the observed $B(E2)$ trend.

6 pages, 5 figures

References in corpus (25)

• Chiral effective field theory and nuclear forces
• Improved nuclear matter calculations from chiral low-momentum interactions
• Gamow Shell Model Description of Neutron-Rich Nuclei
• Shell Model in the Complex Energy Plane
• Eigenvector continuation with subspace learning
• Shell Model Description of Isotope Shifts in Calcium
• Physics of nuclei: Key role of an emergent symmetry
• Nilsson-SU3 selfconsistency in heavy N=Z nuclei
• Gamow shell model and realistic nucleon-nucleon interactions
• Systematics of E2 strength in the sd-shell with the valence-space in-medium similarity renormalization group
• Perturbative Approach to Effective Shell-Model Hamiltonians and Operators
• Information content of the differences in the charge radii of mirror nuclei
• Emergent Sp(3,R) dynamical symmetry in the nuclear many-body system from an ab initio description
• Multiscale physics of atomic nuclei from first principles
• The structure of ${}^{36}$Ca under the Coulomb magnifying glass
• Ab initio descriptions of $A=16$ mirror nuclei with resonance and continuum coupling
• Complex valence-space effective operators for observables: the Gamow-Teller transition
• Broken mirror symmetry in ${}^{36}$S and ${}^{36}$Ca
• First Penning trap mass measurement of ${}^{36}$Ca
• Evaluation of the ${}^{35}$K($p$,$\gamma$)${}^{36}$Ca reaction rate using the ${}^{37}$Ca($p$,$d$)${}^{36}$Ca transfer reaction
• Gamow shell model description of the radiative capture reaction ${}^8$Li$(n,\gamma )$${}^9$Li
• Probing proton cross-shell excitations through the two-neutron removal from 38Ca
• Collectivity of the electromagnetic transitions in near-threshold resonances
• In-beam $\gamma$-ray spectroscopy of negative-parity states of ${}^{37}$K populated in dissipative reactions
• Electromagnetic transitions in near-threshold resonances

Cited by in corpus (2)

• Radii of proton emitters
• Structure evolution of ground and excited states in the exotic nucleus ${}^{22}$Al