Massive neutron stars and Λ-hypernuclei in relativistic mean field models

Based on relativistic mean field (RMF) models, we study finite Lambda-hypernuclei and massive neutron stars. The effective N-N interactions PK1 and TM1 are adopted, while the N-Lambda interactions are constrained by reproducing the binding energy of Lambda-hyperon at 18 orbit of Delta 40Ca. It is found that the Lambda-meson couplings follow a simple relation, indicating a fixed A potential well for symmetric nuclear matter at saturation densities, i.e., around V Lambda = -29.786 MeV. With those interactions, a large mass range of Lambda-hypernuclei can be described well. Furthermore, the masses of PSR J1614-2230 and PSR J0348+0432 can be attained adopting the Lambda-meson couplings g sigma(Lambda)/g sigma(N) greater than or similar to 0.73, g omega(Lambda)/g omega(N) greater than or similar to 0.80 for PK1 and g sigma(Lambda)/g sigma(N) greater than or similar to 0.81, g omega Lambda/g omega N greater than or similar to 0.90 TM1, respectively. This resolves the hyperon puzzle without introducing any additional degrees of freedom.