Measurement of g9/2 strength in the stretched 8− state and other negative parity states via the V51(d,p)V52 reaction

Le résumé fourni par la source

We performed a measurement of the $^{51}\mathrm{V}(d,p)^{52}\mathrm{V}$ reaction at 16 MeV using the Florida State University Super-Enge Split-Pole Spectrograph (SE-SPS) to search for single-neutron transfer strength for the ${g}_{9/2}$ intruder orbit. Measurements of $\ensuremath{\nu}{g}_{9/2}$ strength with ($d,p$) reactions in the $N=29$ isotones $^{49}\mathrm{Ca}, ^{51}\mathrm{Ti}, ^{53}\mathrm{Cr}$, and $^{55}\mathrm{Fe}$ have concluded that much of the expected $\ensuremath{\nu}{g}_{9/2}$ strength is ``missing''; that is, the summed strength is much smaller than the sum rule. In odd-odd $N=29$ isotones, we expect a significant amount of $\ensuremath{\nu}{g}_{9/2}$ strength to be located in the ``stretched'' ${8}^{\ensuremath{-}}$ states with $\ensuremath{\pi}{f}_{7/2}^{n}\ensuremath{\nu}{g}_{9/2}$ structure that were systematically observed in the odd-odd $N=29$ isotones via the $(\ensuremath{\alpha},d)$ reaction. $^{52}\mathrm{V}$ is the only one of these odd-odd isotones in which a stable target is available for single-neutron transfer reactions. We report on a determination of $\ensuremath{\nu}{g}_{9/2}$ strength for the stretched ${8}^{\ensuremath{-}}$ state and ten other negative parity states populated via $L=4$ transfer in the $^{51}\mathrm{V}(d,p)^{52}\mathrm{V}$ reaction. This is the first measurement of spectroscopic strength for $L=4$ states in $^{52}\mathrm{V}$ via ($d,p$). In total, the $L=4$ strength observed here sums to only $28.9(11)%$ of the sum rule for ${g}_{9/2}$ neutron strength, a result that is consistent with the summed strengths observed in recent ($d,p$) measurements of the even-Z $N=29$ isotones $^{51}\mathrm{Ti}, ^{53}\mathrm{Cr}$, and $^{55}\mathrm{Fe}$. The $(\ensuremath{\alpha}{,}^{3}\mathrm{He})$ reaction and the use of particle-$\ensuremath{\gamma}$ coincidences would provide more sensitivity to search for the missing ${g}_{9/2}$ strength.

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