Tensor coupling effects on spin symmetry in the anti-lambda spectrum of hypernuclei
Effects of Λω-tensor coupling on the spin symmetry of Λ spectra in Λ-nucleus systems are studied using relativistic mean-field theory. Taking 12C+Λ as an example, it is found that the tensor coupling enlarges the spin-orbit splittings of Λ by a factor of 5 but has a negligible effect on the wave functions of Λ. Similar conclusions are observed in other Λ-nuclei, including 16O+Λ, 40Ca+Λ and 208Pb+Λ. It is indicated that the spin symmetry in anti-lambda-nucleus systems is still a good approximation irrespective of the tensor coupling. © 2011 Chinese Physical Society and IOP Publishing Ltd.