${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay in scalar and vector leptoquark scenarios

Abstract

It has been shown that the anomalies observed in $\bar{B}\to D^{(\ast )}\tau {\bar{\nu }}_{\tau }$ and $\bar{B}\to \bar{K}{\ell }^{+}{\ell }^{-}$ decays can be resolved by adding a single scalar or vector leptoquark to the Standard Model, while constraints from other precision measurements in the flavour sector can be satisfied without fine-tuning. To further explore these two interesting scenarios, in this paper, we study their effects in the semi-leptonic ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay. Using the best-fit solutions for the operator coefficients allowed by the current data of mesonic decays, we find that (i) the two scenarios give similar amounts of enhancements to the branching fraction $\mathcal{B}({\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau })$ and the ratio $R_{{\Lambda }_c}=\mathcal{B}({\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau })/\mathcal{B}({\Lambda }_b\to {\Lambda }_c\ell {\bar{\nu }}_{\ell })$, (ii) the two best-fit solutions in each of these two scenarios are also indistinguishable from each other, (iii) both scenarios give nearly the same predictions as those of the Standard Model for the longitudinal polarizations of ${\Lambda }_c$ and $\tau$ as well as the lepton-side forward-backward asymmetry. With future measurements of these observables in ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay at the LHCb, the two leptoquark scenarios could be further tested, and even differentiated from the other NP explanations for the $R_{D^{(\ast )}}$ anomalies. We also discuss the feasibility for the measurements of these observables at the LHC and the future $e^{+}{e}^{-}$ colliders.

arXiv comment29 pages, 4 tables and 2 figures; More references and the feasibility for the measurements of the observables in these decays at the LHC and the future $e^{+}{e}^{-}$ colliders added, final version published in the journal

References in corpus (47)

• Heavy Quark Symmetry
• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Evidence for an excess of B -> D(*) Tau Nu decays
• Measurement of an Excess of B -> D(*) Tau Nu Decays and Implications for Charged Higgs Bosons
• Measurement of the branching ratio of $\bar{B}\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ relative to $\bar{B}\to D^{(\ast )}{\ell }^{-}{\bar{\nu }}_{\ell }$ decays with hadronic tagging at Belle
• Physics of leptoquarks in precision experiments and at particle colliders
• More Model-Independent Analysis of b->s Processes
• One Leptoquark to Rule Them All: A Minimal Explanation for $R_{D^{(\ast )}}$, $R_K$ and $(g-2{)}_{\mu }$
• On the Standard Model predictions for $R_K$ and $R_{K^{\ast }}$
• Effective field theory approach to $b\to s\ell {\ell }^{(\prime )}$, $B\to K^{(\ast )}\nu \bar{\nu }$ and $B\to D^{(\ast )}\tau \nu$ with third generation couplings
• Model-independent description of $B\to \pi l\nu$ decays and a determination of $|V_{ub}|$
• Anomalies in $B$-decays and $U(2)$ flavour symmetry
• Vector leptoquark resolution of $R_K$ and $R_{D^{(\ast )}}$ puzzles
• Confronting lepton flavor universality violation in B decays with high-$p_T$ tau lepton searches at LHC
• Implications of lepton flavor universality violations in B decays
• Heavy baryons
• Simultaneous Explanation of the $R_K$ and $R(D^{(\ast )})$ Puzzles
• $B\to Dl\nu$ Form Factors at Non-Zero Recoil and Extraction of $|V_{cb}|$
• A perturbed lepton-specific two-Higgs-doublet model facing experimental hints for physics beyond the Standard Model
• Non-abelian gauge extensions for B-decay anomalies
• Sensitivity to charged scalars in $B\to D^{(\ast )}\tau {\nu }_{\tau }$ and $B\to \tau {\nu }_{\tau }$ decays
• Measurement of b hadron production fractions in 7 TeV pp collisions
• Determination of the quark coupling strength $|V_{ub}|$ using baryonic decays
• Simultaneous Explanation of the $R_K$ and $R_{D^{(\ast )}}$ Puzzles: a Model Analysis
• Leptoquark Flavor Patterns & B Decay Anomalies
• Phenomenology of an $SU(2)\times SU(2)\times U(1)$ model with lepton-flavour non-universality
• Measurements of absolute hadronic branching fractions of ${\Lambda }_c^{+}$ baryon
• Charged Higgs Effects on Exclusive Semi-tauonic $\bbox{B}$ Decays
• The semileptonic decay Lambda_b -> Lambda_c + tau(-) + antinu_tau in the covariant confined quark model
• Form Factors for Lambda_b -> Lambda Transitions in SCET
• Baryonic Rare Decays of ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$
• Measurement of the Branching Fraction Br(Lambda_c+ -> p K- pi+)
• The Full $B\to D^{\ast }{\tau }^{-}\overline{{\nu }_{\tau }}$ Angular Distribution and CP violating Triple Products
• Measurement of the absolute branching fraction for ${\Lambda }_c^{+}\to \Lambda e^{+}{\nu }_e$
• A closer look at the $R_D$ and $R_{D^{\ast }}$ anomalies
• Hints of R-parity violation in B decays into $\tau \nu$
• Measurements of the Lambda_b0 -> J/psi Lambda decay amplitudes and the Lambda_b0 polarisation in pp collisions at sqrt(s) = 7 TeV
• New Physics in the Visible Final States of $B\to D^{(\ast )}\tau \nu$
• Helicity Analysis of Semileptonic Hyperon Decays Including Lepton Mass Effects
• Form Factors and Decay Rates for Heavy $\Lambda$ Semileptonic Decays from QCD Sum Rules
• Measurement of the Absolute Branching Fraction for ${\Lambda }_c^{+}\to \Lambda {\mu }^{+}{\nu }_{\mu }$
• Improving constraints on tan(beta)/m_H using B \to D tau \bar{nu}
• Semileptonic decays $B\to D^{(\ast )}l\nu$ in the perturbative QCD factorization approach
• $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ excesses in ALRSM constrained from $B$, $D$ decays and $D^0-{\bar{D}}^0$ mixing
• Exploring top quark FCNC within 2HDM type III in association with flavor physics
• Lepton angular asymmetries in semileptonic charmful B decays
• Semileptonic and leptonic $B$ decays, circa 2016

Cited by in corpus (30)

• Scalar contributions to $b\to c(u)\tau \nu$ transitions
• Footprints of New Physics in $b\to c\tau \nu$ Transitions
• Precise predictions for ${\Lambda }_b\to {\Lambda }_c$ semileptonic decays
• Investigation of Effects of New Physics in ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ Decay
• Impact of ${\Lambda }_b\to {\Lambda }_c\tau \nu$ measurement on New Physics in $b\to cl\nu$ transitions
• Probing new physics in semileptonic ${\Lambda }_b$ decays
• Beyond $\mathcal{R}(D^{(\ast )})$ with the general 2HDM-III for $b\to c\tau \nu$
• Global fit to $b\to c\tau \nu$ anomalies as of Spring 2024
• Phenomenology of $b\to c\tau \bar{\nu }$ decays in a scalar leptoquark model
• Review of Semileptonic $B$ Anomalies
• Further tests of lepton flavour universality from the charged lepton energy distribution in $b\to c$ semileptonic decays: The case of ${\Lambda }_b\to {\Lambda }_c\ell {\bar{\nu }}_{\ell }$
• ${\Lambda }_b\to {\Lambda }_c^{\ast }(2595,2625){\ell }^{-}\bar{\nu }$ form factors from lattice QCD
• The measurable angular distribution of ${\Lambda }_b^0\to {\Lambda }_c^{+}(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decay
• Hadron and lepton tensors in semileptonic decays including new physics
• Amplitude analysis of the ${\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+}$ decay and ${\Lambda }_c^{+}$ baryon polarization measurement in semileptonic beauty hadron decays
• Probing effects of new physics in ${\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}{\bar{\nu }}_{\mu }$ decays
• Form Factor Counting and HQET Matching for New Physics in ${\Lambda }_b\to {\Lambda }_c^{\ast }l\nu$
• Heavy baryon wave functions, Bakamjian-Thomas approach to form factors, and observables in ${\Lambda }_b\to {\Lambda }_c\left({\frac{1}{2}}^{\pm }\right)\ell \overline{\nu }$ transitions
• Effect of scalar leptoquarks on the lepton flavor violation decays of B meson
• On sum rules for semi-leptonic $b\to c$ and $b\to u$ decays
• $b\to c\tau \bar{\nu }$ decays in supersymmetry with $R$-parity violation
• Time-reversal asymmetries in ${\Lambda }_b$ semileptonic decays
• New physics effects on ${\Lambda }_b\to {\Lambda }_c^{\ast }\tau {\bar{\nu }}_{\tau }$ decays
• Extracting maximum information from polarised baryon decays via amplitude analysis: the ${\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+}$ case
• Baryonic heavy-to-light form factors induced by tensor current in light-front approach
• New physics in the angular distribution of $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decay
• An Imperative study of the angular observables in ${\Lambda }_b\to {\Lambda }_c^{+}(\to \Lambda {\pi }^{+}){\ell }^{-}{\bar{\nu }}_{\ell }$ decay and probing the footprint of new physics
• Visible energy and angular distributions of the charged particle from the $\tau -$decay in $b\to c\tau (\mu {\bar{\nu }}_{\mu }{\nu }_{\tau },\pi {\nu }_{\tau },\rho {\nu }_{\tau }){\bar{\nu }}_{\tau }$ reactions
• Addressing the $R_{\tau /\mu ,e}\left(D^{(\ast )}\right)$ puzzle through New Physics four-fermion operators and their impact on ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay
• Predictions for ${\Lambda }_b\to {\Lambda }_c\tau \bar{\nu }$ in BLSSM with Inverse seesaw