CP asymmetry in tau -> K pi nu(tau) within non-minimal SU(5)

Direct CP asymmetry in semi-leptonic tau decays is an intriguing hint for new physics beyond the standard model. We investigate the CP asymmetry in tau(-) -> K-S(0)pi(-)nu(tau) and tau(-) -> K-pi(0)nu(tau) decays in the context of the non-minimal SU(5) model, with 45-dimensional Higgs multiplet. We show that the associate color-triplet scalar, which is a natural example of a scalar leptoquark, can mediate the tau -> s (u) over bar nu(tau) transition and account for the observed 2.8 sigma discrepancy in A(CP)(tau(-) -> K-S(0)pi(-)nu(tau)) compared to the SM expectation. We also predict a sizable A(CP)(tau(-) -> K-pi(0)nu(tau)), of O(10(-3)), which can be experimentally accessible in current and near future experiments.