Journal of High Energy Physics, vol.2023, no.5, 2023 (SCI-Expanded)
Direct CP asymmetry in semi-leptonic τ decays is an intriguing hint for new physics beyond the standard model. We investigate the CP asymmetry in τ−→KS0π−ντ and τ − → K − π 0 ντ 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 τ→ su¯ ντ transition and account for the observed 2.8 σ discrepancy in ACP(τ−→KS0π−ντ) compared to the SM expectation. We also predict a sizable A CP(τ − → K − π 0 ντ), of O (10 −3), which can be experimentally accessible in current and near future experiments.