Relativistic Mean-Field and Beyond Approaches for Deformed Hypernuclei

We report the recent progress in relativistic mean-field (RMF) and beyond approaches for the low-energy structure of deformed hypernuclei. We show that the Lambda hyperon with orbital angular momentum l = 0 (or l > 1) generally reduces (enhances) nuclear quadrupole collectivity. The beyond mean-field studies of hypernuclear low-lying states demonstrate that there is generally a large configuration mixing between the two components [(A-1)Z(I+) circle times Lambda p(1/2)](J) and [(A-1)Z(I +/- 2(+)) circle times Lambda p(3/2)](J) in the hypernuclear 1/2(1)(-) ; 3/2(1)(-) states. The mixing weight increases as the collective correlation of nuclear core becomes stronger. Finally, we show how the energies of hypernuclear low-lying states are sensitive to parameters in the effective N Lambda interaction, the uncertainty of which has a large impact on the predicted maximum mass of neutron stars.