New-physics effects on triple-product correlations inΛbdecays

We adopt an effective-Lagrangian approach to compute the new-physics contributions to T-violating triple-product correlations in charmless ${\Lambda }_b$ decays. We use factorization and work to leading order in the heavy-quark expansion. We find that the standard-model (SM) predictions for such correlations can be significantly modified. For example, triple products which are expected to vanish in the SM can be enormous $(\sim 50\%)$ in the presence of new physics. By measuring triple products in a variety of ${\Lambda }_b$ decays, one can diagnose which new-physics operators are or are not present. Our general results can be applied to any specific model of new physics by simply calculating which operators appear in that model.