Abstract
In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these intriguing results, we perform a model independent analysis of the semileptonic $\Lambda_b$ decays involving the quark level transitions $b \to (u,c) l \nu_l$, in order to scrutinize the nature of new physics. We constrain the new parameter space by using the measured branching ratios of $B_{c, u}^+ \to \tau^+ \nu_\tau$, $B \to \pi \tau \nu_\tau$ processes and the existing experimental results on $R_{D^{(*)}}$, $R_{J/\psi}$ and $R_{\pi}^l$ parameters. Using the constrained parameters, we estimate the branching ratios, forward backward asymmetries, hadron and lepton polarization asymmetries of the $\Lambda_b \to (\Lambda_c, p) l \nu_l$ processes. Moreover, we also examine whether there could be any lepton universality violation in these decay modes.
Highlights
Though the Standard Model (SM) is considered as the most fundamental theory describing almost all the phenomena of particle physics, still it is unable to shed light on some of the open issues, like matter-antimatter asymmetry, dark matter, dark energy, etc., which eventually necessitates probing the physics beyond it
We observe that the lepton nonuniversality (LNU) parameter, longitudinal hadron, and lepton polarization asymmetries of the Λb → pτντ process have a large deviation from their SM values due to the presence of tensor coupling, whereas negligible deviations (RΛc has some deviation from its SM result) are noticed for the observables of the Λb → Λcτντ decay mode
We have performed a model-independent analysis of baryonic Λb → ðΛc; pÞlνl decay processes by considering the generalized effective Lagrangian in the presence of new physics
Summary
Though the Standard Model (SM) is considered as the most fundamental theory describing almost all the phenomena of particle physics, still it is unable to shed light on some of the open issues, like matter-antimatter asymmetry, dark matter, dark energy, etc., which eventually necessitates probing the physics beyond it In this respect, the rare decays of B mesons involving the flavor changing neutral current (FCNC) transitions play an important role in the quest for new physics (NP). The main difference between our approach and the previous analyses in [25,32] is that we investigate the impact of individual complex new couplings on all the angular observables, including the lepton and hadron polarization asymmetries.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
