The radiative decays of b-baryons facilitate the direct measurement of photon helicity in b → sγ transitions thus serving as an important test of physics beyond the Standard Model. In this paper we analyze the complete angular distribution of ground state b-baryon radiative decays to multibody final states assuming an initially polarized bbaryon sample. Our sensitivity study suggests that the photon polarization asymmetry can be extracted to a good accuracy along with a simultaneous measurement of the initial bbaryon polarization. With higher yields of b-baryons, achievable in subsequent runs of the Large Hadron Collider (LHC), we find that the photon polarization measurement can play a pivotal role in constraining different new physics scenarios.

The flavor changing rare decay B → K * (→ Kπ) + − is one of the most studied modes due to its sensitivity to physics beyond the standard model and several discrepancies have come to light among the plethora of observables that are measured. In this paper we revisit the analogous baryonic decay mode Λ b → Λ(→ pπ) + − and we present a complete set of ten angular observables that can be measured using this decay mode. Our calculations are done retaining the finite lepton mass so that the signal of lepton non-universality observed in B → K * + − can be corroborated by the corresponding baryonic decay mode. We show that due to the parity violating nature of the subsequent Λ → pπ decay there exist at least one angular asymmetry that is non-vanishing in the large recoil limit unlike the case in B → K * + − decay mode, making it particularly sensitive to new physics that violates lepton flavor universality.

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