A detailed view at magnetic dipole strengths: The case of semi-magic ${}^{50}$Ti

Abstract

Magnetic dipole, $M1$, strengths were studied in semi-magic ${}^{50}$Ti up to the neutron-separation threshold by combining data from $(d,p)$ one-neutron transfer, $(\gamma ,{\gamma }^{\prime })$ real-photon scattering, $(e,e^{\prime })$ inelastic scattering at extreme backward angles, and $(p,p^{\prime })$ at $E_p=210$ MeV and extreme forward angles. The combination of all probes provided unique access to the neutron spin-flip contribution and the possibility to evaluate its role in generating the spin-flip $M1$ strengths. The small contribution of the neutron $(1f_{7/2}{)}^{-1}(1f_{5/2}{)}^{+1}$ spin-flip transitions, which were probed with the $(d,p)$ reaction, to the overall strength in ${}^{50}$Ti questions the standard picture for the microscopic origin of spin-flip strength in the $fp$ shell. For ${}^{50}$Ti, this letter shows that $J^{\pi }=1^{+}$ states with larger neutron $(1f_{7/2}{)}^{-1}(1f_{5/2}{)}^{+1}$ spectroscopic factors do not correspond to the ones with the largest $B(M1;0_1^{+}\to 1_i^{+})$ strengths.

Comments: 7 pages, 3 figures, published in Physical Review Letters