Searching for New Physics in Semi-Leptonic Baryon Decays

Abstract

We propose two different and complementary observables for singling out possible signals of physics beyond the standard model in the semi-leptonic decays ${\Lambda }_b\to {\Lambda }_c\ell {\bar{\nu }}_{\ell }$, both with the $\tau$ lepton and with a light lepton. The two observables are the partial decay width and a T-odd asymmetry, whose respective sensitivities to scalar and/or pseudo-scalar coupling are calculated as functions of the parameters characterizing new physics. Two different form factors are used. Three particular cases are discussed and analyzed in detail.

arXiv comment14 pages, 2 figures

References in corpus (30)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• 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
• Measurement of the ratio of branching fractions $\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\mu }^{-}{\overline{\nu }}_{\mu })$
• Measurement of form-factor independent observables in the decay $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$
• New physics in $b\to s$ transitions after LHC run 1
• ${\Lambda }_b\to p{\ell }^{-}{\bar{\nu }}_{\ell }$ and ${\Lambda }_b\to {\Lambda }_c{\ell }^{-}{\bar{\nu }}_{\ell }$ form factors from lattice QCD with relativistic heavy quarks
• Diagnosing New Physics in $b\to c\tau {\nu }_{\tau }$ decays in the light of the recent BaBar result
• ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ form factors, differential branching fraction, and angular observables from lattice QCD with relativistic $b$ quarks
• The semileptonic decay Lambda_b -> Lambda_c + tau(-) + antinu_tau in the covariant confined quark model
• Rare baryon decays Lambda_b -> Lambda l+ l- (l=e, mu, tau) and Lambda_b -> Lambda gamma : Differential and total rates, lepton- and hadron-side forward-backward asymmetries
• ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ Decay in the Standard Model and with New Physics
• Diquarks and Λ_{b}\toΛ_c weak decays
• Triple product asymmetries in K, D_(s) and B_(s) decays
• ${\Lambda }_b\to ({\Lambda }_c,p)\tau \nu$ decays within standard model and beyond
• Lambda_b -> Lambda l+ l- form factors and differential branching fraction from lattice QCD
• New-Physics Effects on Triple-Product Correlations in Lambda_b Decays
• T-Odd Triple-Product Correlations in Hadronic b Decays
• The Higgs: so simple yet so unnatural
• Infinite Momentum Frame Calculation of Semileptonic Heavy Λ_b\toΛ_c Transitions Including HQET Improvements
• Diquarks and the Semi-Leptonic Decay of ${\Lambda }_b$ in the Hybrid Scheme
• Study of CP violation in ${\Lambda }_c^{+}$ decay
• On the Trail of the Higgs Boson
• Bound on the curvature of the Isgur-Wise function of the baryon semileptonic decay Lambda_b -> Lambda_c + l + nu
• T-violating triple product asymmetries in Lambda_b --> Lambda pi pi decay
• Physical observables in the decay ${\Lambda }_b\to {\Lambda }_c(\to \Lambda +\pi )+{\tau }^{-}+{\bar{\nu }}_{\tau }$
• New results on the baryon decay Lambda_b -> Lambda_c ell nu in Heavy Quark Effective Theory