Niladribihari Sahoo | Searcharxiv

arXiv2023

$Λ_b\rightarrow Λ(\to p π^-) \ell^+\ell^-$ as probe of CP-violating New Physics

We investigate the possible sizes of all the CP-violating asymmetries offered by the angular distribution of rare decay $Λ_b\rightarrow Λ(\to p π^-) \ell^+\ell^-$ in the Standard Model and new physics scenarios motivated by the recent $b\to s \ell^+\ell^-$ anomalies. We work in a model-independent effective theory framework and discuss the sensitivity of CP asymmetries to new ${O}_{9,10}$ operators and their chirality flipped counterparts. We find that the size of many of the CP asymmetries can be at the level of a few percent in new physics scenarios consistent with current $b\to s\ell^+\ell^-$ data at a level of $1σ$. We emphasize that measurements of these CP asymmetries can be used to discriminate different new physics scenarios in $b\to s \ell^+\ell^-$.

hep-ph↗

arXiv2021

Angular analysis of $B_s\, \to\, f_{2}'\,(1525)\,(\to K^+\,K^-)\,μ^+ \,μ^-$ decays as a probe to lepton flavor universality violation

The flavor anomalies reported in $R_K$, $R_{K^*}$, $P_{5}^{\prime}$ and $\mathcal{B}(B_s\, \to\, ϕ\, μ^+\, μ^-)$ indicate lepton flavor universality violation in $b \to s\,l^+\,l^-$ quark level transition decays. The deviation from the SM prediction reported in the underlying flavor observables currently stand at the level of $2.5σ$, $2.4σ$, $3.3σ$ and $3.7σ$, respectively. In this context, we perform an angular analysis of the four-body differential decay of $B_s\, \to\, f_{2}^{\prime}\,(1525)\,(\to K^+\,K^-)\,μ^+ \,μ^-$ in a model independent effective field theory framework. The decay mode $B_s\, \to\, f_{2}^{\prime}(1525)\,l^+\,l^-$ undergoes similar $b \to s$ neutral current quark level transition and, in principle, can provide complementary information regarding lepton flavor universality violation in $b \to s\,l^+\,l^-$ quark level transition decays. We give predictions of various physical observables such as the branching ratio, the longitudinal polarization fraction, the forward-backward asymmetry, the angular observables $P_1$, $P_2$, $P_{4}^{\prime}$, $P_{5}^{\prime}$ and also the lepton flavor sensitive observables such as the ratio of branching ratio $R_{f_{2}^{\prime}}$, $Q_{F_L}$, $Q_{A_{FB}}$, $Q_{1}$, $Q_{2}$, $Q_{4}^{\prime}$, $Q_{5}^{\prime}$ for $B_s\, \to\, f_{2}^{\prime}\,(1525)\,(\to K^+\,K^-)\,μ^+ \,μ^-$ decays in the standard model and in the presence of several 1D and 2D new physics scenarios.

hep-ph↗

arXiv2017

Rare $B$ decays at CMS

The Flavor Changing Neutral Current mediated decays $B \rightarrow μ^{+}μ^{-}$ and $B^{0} \rightarrow K^{*0}μ^{+}μ^{-}$ provide high sensitivity to new physics contributions. Sensitive observables include the branching fraction, the muon forward-backward asymmetry, the fraction of $K^{*0}$ longitudinal polarisation and the differential branching fraction. We report herein the recent results from CMS on these decay modes.

hep-ex↗