Effect of asymmetric strange-antistrange sea to the NuTeV anomaly

We calculate the strange quark and antiquark distributions of the nucleon by using the effective chiral quark model, and find that the strange-antistrange asymmetry can bring a contribution of about 60-100% to the NuTeV deviation of sin2θw from the standard value measured in other electroweak processes. The results are insensitive to different inputs. The light-flavor quark asymmetry of d¯-u¯ is also investigated and found to be consistent with the experimental measurements. Therefore the chiral quark model provides a successful picture to understand the NuTeV anomaly, as well as the light-flavor quark asymmetry and the proton spin problem in previous studies.