Speaker
Description
The study of single-particle states can provide insight into properties of nuclear structure. In light neutron-rich systems, features of single-particle states along isotonic chains have highlighted changes in shell closures, such as the weakening of $N=20$ and formation of $N=16$ [1, 2]. In heavier closed-shell stable nuclei, trends have been seen in the behaviour of high-j states from the filling of other high-j orbitals, the effects of which have been attributed to the tensor interaction [3]. From the availability of radioactive beams at ISOLDE, these studies can be extended in the region around $N=126$. Currently, states up to $Z=84$ are known with spectroscopic factors and assignments [4, 5]. Above this, only the energies of states are available with tentatively assigned orbital configurations and no spectroscopic information. In order to probe single-particle nature beyond this, the reaction d($^{212}$Rn, p)$^{213}$Rn has been performed at the ISOLDE Solenoidal Spectrometer (ISS) with a 7.63 MeV/u radioactive beam at an intensity of $\sim$10$^6$ pps. States have been identified up to $\sim$4 MeV. The aim is to extract and calculate single-particle centroids for the neutron outside of $N=126$. These will provide information on the magnitude of monopole shifts caused by the interaction between the neutron and protons filling the $\pi0h_{9/2}$ orbital. These data will also be used to inform modern shell-model calculations in this region of the nuclear chart. Preliminary data from measurements, made in September, will be presented.
References
[1] A. Ozawa et al. Phys. Rev. Lett. 84, 5493 (2000).
[2] C. R. Hoffman et al. Phys. Lett. B 672, 17 (2009).
[3] T. Otsuka et al. Phys. Rev. Lett. 95, 232502 (2005).
[4] T. L. Tang et al. Phys. Rev. Lett. 124, 062502 (2020).
[5] T. S. Bhatia et al. Nuc. Phys. A. 314, 101 (1979).
