A novel strategy for searching for $CP$ violations in the baryon sector

Abstract

Despite the large baryon-anti-baryon asymmetry in the observable Universe, the closely related phenomenon -- the violation of the combined charge and parity symmetry ($CP$V) -- has not been observed in the baryon sector in laboratories. In this paper, a new strategy for searching for $CP$V in heavy hadron multi-body decays is proposed, in which a set of novel observables measuring $CP$V in such decays -- the partial wave $CP$ asymmetries (PW$CP$As) -- are introduced. This strategy is model-independent and applicable to multi-body decays of heavy hadrons with arbitrary spin configurations in both initial and final states, and with any number of particles in the final state. It is especially applicable for $CP$V investigations in multi-body decays of heavy baryons. As applications of this strategy, we suggest to measure the PW$CP$As in some decay channels of bottom baryons such as ${\Lambda }_b^0\to p{\pi }^{-}{\pi }^{+}{\pi }^{-}$, ${\Lambda }_b\to p{K}^{-}{\pi }^{+}{\pi }^{-}$, ${\Lambda }_b^0\to p{\pi }^{-}{K}^{+}{K}^{-}$, ${\Lambda }_b^0\to \Lambda K^{+}{\pi }^{-}$, and ${\Lambda }_b^0\to p{\pi }^{-}{K}_s$.}

Comments: 15 pages, 4 figures, 2 tables, accepted for publication in JHEP