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

Abstract

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 (CPV) — has not been observed in the baryon sector in laboratories. In this paper, a new strategy for searching for CPV in heavy hadron multi-body decays is proposed, in which a set of novel observables measuring CPV in such decays — the partial wave CP asymmetries (PWCP 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 CPV investigations in multi-body decays of heavy baryons. As applications of this strategy, we suggest to measure the PWCP As in some decay channels of bottom baryons such as $$ {\Lambda}_b^0\to p{\pi}^{-}{\pi}^{+}{\pi}^{-} $$ Λ b 0 → p π − π + π − , Λb → pK−π+π−, $$ {\Lambda}_b^0\to p{\pi}^{-}{K}^{+}{K}^{-} $$ Λ b 0 → p π − K + K − , $$ {\Lambda}_b^0\to \Lambda {K}^{+}{\pi}^{-} $$ Λ b 0 → Λ K + π − , and $$ {\Lambda}_b^0\to p{\pi}^{-}{K}_s $$ Λ b 0 → p π − K s .