Single Particle states in $^{131,133}$Sn and r-process nucleosynthesis*

The (d,p) transfer reaction was recently used with radioactive $^{130}$Sn and $^{132}$Sn beams to determine four strong single-particle bound levels in $^{131,133}$Sn. These levels have strikingly similar excitation energy spacings that have not yet been addressed by a theoretical nuclear structure model. Information on these single particle bound levels, as well as on resonant levels above the neutron capture threshold, are also needed to determine the $^{130,132}$Sn neutron capture cross sections -- and their corresponding thermonuclear reaction rates -- which (in the case of $^{130}$Sn) significantly impacts the synthesis of heavy elements in the r-process in supernovae. We used the analytical continuation of the coupling constant (ACCC) method based on a relativistic mean field theory with BCS approximation to self-consistently calculate single-particle bound and resonant levels for $^{131,133}$Sn. Our results for the single particle bound and resonant levels in $^{131,133}$Sn will be presented, along with our level densities and the implications for neutron capture cross sections for r-process studies.