arXiv subjects

Priyanka Boora

Publications and source records attributed to Priyanka Boora.

3 recordsLinked to original sources

arXiv2026

Probing Signatures of Right-Handed Neutrinos via $b \to s \nu \bar\nu$ Decays

The recent Belle II measurement of $\mathcal{B}(B^+\to K^+\nu\bar{\nu})$, which deviates from the Standard Model prediction, provides a strong motivation to search for New Physics in $b\to s\nu\bar{\nu}$ transitions. We perform a model-independent analysis within the low-energy effective theory, focusing on dimension-six vector operators involving right-handed neutrinos. Using the Belle II measurement of $\mathcal{B}({B\to K\nu\bar{\nu}})$ together with the upper limit on $\mathcal{B}({B\to K^{*}\nu\bar{\nu}})$, we constrain the new physics interactions. We study the correlation of $\mathcal{B}({B\to K\nu\bar{\nu}})$ with $\mathcal{B}({B\to K^{*}\nu\bar{\nu}})$, $\mathcal{B}({B_s\to\phi\nu\bar{\nu}})$, $\mathcal{B}({\Lambda_b\to\Lambda\nu\bar{\nu}})$, and the longitudinal polarization fraction $F_L^{K^*}$. We find sizeable enhancements in all branching fractions studied, while $F_L^{K^*}$ offers complementary sensitivity to the underlying RHN interaction structure. These results provide testable signatures of right-handed neutrino interactions at Belle~II and LHCb, and at the future FCC-ee experiment.

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arXiv2026

A comprehensive study of $Λ_c^- \to Λ(\to p π) μ^- \bar ν_μ$ incorporating SMEFT implications and right-handed neutrino

We present a comprehensive analysis of the decay $Λ_c^- \to Λ(\to pπ)\,μ^- \barν_μ$ within a model-independent effective field theory framework. Previous studies have been restricted to the three-body decay $Λ_c^+ \to Λμ^+ ν_μ$ and considered only left-handed neutrinos within the Low-Energy Effective Theory (LEFT). In this work, we extend the analysis to the complete four-body angular distribution for the first time, incorporating the indirect constraints implied by the Standard Model Effective Field Theory (SMEFT) on the LEFT Wilson coefficients. We also include the effects of right-handed neutrino (RHN) operators, enabling a unified treatment of both left- and right-handed neutrino interactions in the $c \to s μν_μ$ transition. Using the global bounds derived from LEFT observables and their SMEFT correlations, we study the impact of allowed new-physics scenarios on a variety of observables, including differential decay rates, forward-backward asymmetries, polarization asymmetries of the final-state hadron and lepton, and the angular coefficients (${\cal M}_0$ to ${\cal M}_9$) in the 4-body angular distribution. Our analysis reveals significant deviations from the Standard Model in the observables $\mathcal{P}^Λ_L$ and ${\cal M}_1$ for $C^V_{RL}$ and $C^V_{RR}$, and striking $T$-odd effects in ${\cal M}_7$ for complex $C^V_{RL}$. These features provide sensitive probes of vector-type new physics, such as leptoquark or right-handed current models. The predicted patterns can be tested in forthcoming measurements at BESIII, LHCb, and Belle II, where polarization-sensitive observables in $Λ_c$ decays are becoming experimentally accessible.

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arXiv2025

New Physics effects with right-handed neutrinos in semileptonic decay $B_c^+ \to B_s μ^+ ν_μ$

We extend the Standard Model with the general effective Hamiltonian for the quark level transition $c \to s \ell ν$ with a complete set of four fermion operators including right-handed neutrinos. The current experimental measurements in charm decays are compatible with the Standard Model predictions and are used to constrain the new physics. With the available experimental data, we fit a $χ^2$ function to get the best-fit values of the NP WCs. We investigate the impact of allowed new physics in the observables such as differential branching fraction, forward-backward asymmetry, lepton polarization asymmetry, and convexity parameter in the semileptonic decay $B_c^+ \to B_s μ^+ ν_μ$. The different types of new physics scenarios have significant effects on these considered observables. The future experimental information of these observables can help to disentangle the structure of new physics.

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