#### IMSc Webinar

#### Model independent study of the rare decay of b-Baryon

#### Ria Sain

##### IMSc

*The study of baryonic decay mode $\Lambda_b \to \Lambda \ell^{+}\ell^{-}$ is of interest in relation to the recent flavor anomalies. Based on the SM of particle physics, we study the decay in light of the available inputs from lattice and the data from LHCb. We fit the form-factors of this decay mode using the available theory and experimental inputs after defining different fit scenarios and checking their consistencies. Utilizing the fit results, we predict a few observables and lepton universality testing $R_{\Lambda}$ related to the decay. This decay with a polarized $\Lambda_b$ offers a plethora of observables that are suitable to discriminate New Physics from the Standard Model.*

We study the angular analysis of the decay for SM operator basis with its chirality flipped counterparts, and new scalar and pseudo-scalar operators, retaining the mass of the final state leptons. At the low hadronic recoil, we use the HQET framework to relate the hadronic form factors which lead to simplified expression of the angular observables where short- and long-distance physics

factorize. Using the factorized expressions of the observables, we construct several tests of short-and long-distance physics including null tests of the SM and its chirality flipped counterparts that can be carried out using experimental data.

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