Ab initio computation of the magnetic dipole transition in ⁴⁸Ca

We perform ab initio computation of the magnetic dipole transition in ⁴⁸Ca in coupled-cluster theory using interactions and currents from chiral effective field theory. Our computation includes the effects of the continuum as well as the contributions of many-body correlations in the nuclear wave functions and electromagnetic currents. We find that the transition strength B(M1) lies in the range from 7.0 to 10.2 μ_N², which agrees with a (γ,n) experiment but is larger than the results from inelastic electron- and proton-scattering experiments. We validate our prediction by computing magnetic moments of several odd-mass isotopes of Calcium and by performing benchmarks with the no-core shell model calculations on Oxygen isotopes.