Abstract
The magnetic dipole transition strength ๐ตโก(๐โข1) of 48Ca is dominated by a single resonant state at an excitation energy of 10.23 MeV. Experiments disagree about ๐ตโก(๐โข1) and this impacts our understanding of spin flips in nuclei. We performed ab initio computations based on chiral effective field theory and found that ๐ตโก(๐โข1:โโ0+โ1+) lies in the range from 7.0 to 10.2โโ๐2
๐. This is consistent with a (๐พ,๐) experiment but larger than results from (๐,๐โฒ) and (๐,๐โฒ) scattering. Two-body currents yield no quenching of the ๐ตโก(๐โข1) strength and continuum effects reduce it by about 10%. For a validation of our approach, we computed magnetic moments in 47,49Ca and performed benchmark calculations in light nuclei.
