We evaluate the medium effects in nucleon which can induce an asymmetry of the strange sea. The short-distance effects determined by the weak interaction can give rise to $\delta m\equiv \Delta m_s-\Delta m_{ \bar s}$ where $\Delta m_{ s(\bar s)}$ is the medium-induced mass of strange quark by a few KeV at most, but the long-distance effects by strong interaction could be sizable.
Categories: hep-ph