Magnetic dipole transition in ${}^{48}$Ca

Abstract

The magnetic dipole transition strength $B(M1)$ of ${}^{48}$Ca is dominated by a single resonant state at an excitation energy of 10.23 MeV. Experiments disagree about $B(M1)$ and this impacts our understanding of spin flips in nuclei. We performed ab initio computations based on chiral effective field theory and found that $B(M1:0^{+}\to 1^{+})$ lies in the range from $7.0$ to $10.2\hat{I}{¼}_N^2$. This is consistent with a $({\hat{I}}^3,n)$ experiment but larger than results from $(e,e^{\prime })$ and $(p,p^{\prime })$ scattering. Two-body currents yield no quenching of the $B(M1)$ strength and continuum effects reduce it by about 10%. For a validation of our approach, we computed magnetic moments in ${}^{47,49}$Ca and performed benchmark calculations in light nuclei.

Published version