Heavy quark symmetry of ${\Lambda }_b^0$ decays in quark models

Abstract

We study the heavy quark symmetry with the homogeneous bag model (HBM) and light-front quark model (LFQM) based on the decays of ${\Lambda }_b^0\to {\Lambda }_c^{+}{\ell }^{-}{\overline{\nu }}_{\ell }(\ell =e,\mu ,\tau )$. In particular, we calculate various parameters in the heavy quark expansions, including the Isgur-Wise functions and their first order corrections. The parameters in the HBM are fitted from the mass spectra, while the ones in the LFQM are tightly constrained by the heavy quark symmetry, granting the predictive power of our results. We explicitly obtain that $\mathcal{B}({\Lambda }_b^0\to {\Lambda }_c^{+}{e}^{-}{\overline{\nu }}_e)=(5.69\pm 0.58,5.35\pm 0.50)$, $\mathcal{B}({\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}{\overline{\nu }}_{\mu })=(5.67\pm 0.58$, $5.33\pm 0.49)$, and $\Gamma ({\Lambda }_b^0\to {\Lambda }_c^{+}{\tau }^{-}{\overline{\nu }}_{\tau })/\Gamma ({\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}{\overline{\nu }}_{\mu })=(0.3243\pm 0.0126$, $0.3506\pm 0.0046)$ for the numerical values of (HBM, LFQM). Our results of the branching fractions in both models agree well with the experimental data and lattice QCD calculations. In addition, we find that the hard gluon corrections decrease the branching fractions around $10\%$.

arXiv comment24 pages, 5 figures

References in corpus (45)

• Test of lepton universality in beauty-quark decays
• ${\Lambda }_b\to p{\ell }^{-}{\bar{\nu }}_{\ell }$ and ${\Lambda }_b\to {\Lambda }_c{\ell }^{-}{\bar{\nu }}_{\ell }$ form factors from lattice QCD with relativistic heavy quarks
• Mesonic Form Factors and the Isgur-Wise Function on the Light-Front
• Weak Decays of Doubly Heavy Baryons: the $1/2\to 1/2$ case
• The semileptonic decay Lambda_b -> Lambda_c + tau(-) + antinu_tau in the covariant confined quark model
• Relativistic Constituent Quark Model of Electroweak Properties of Baryons
• Second Order Power Corrections in the Heavy Quark Effective Theory II. Baryon Form Factors
• Semileptonic decays of heavy baryons in the relativistic quark model
• Diquarks and Λ_{b}\toΛ_c weak decays
• Observation of the decay ${\Lambda }_b^0\to {\Lambda }_c^{+}{\tau }^{-}{\overline{\nu }}_{\tau }$
• Semileptonic decays of ${\Lambda }_b$ baryons in the relativistic quark model
• Precise predictions for ${\Lambda }_b\to {\Lambda }_c$ semileptonic decays
• Nonvanishing zero modes in the light-front current
• New predictions for ${\Lambda }_b\to {\Lambda }_c$ semileptonic decays and tests of heavy quark symmetry
• ${\Sigma }_b\to {\Sigma }_c$ and ${\Omega }_b\to {\Omega }_c$ weak decays in the light-front quark model
• Measurement of the shape of the ${\Lambda }_b^0\to {\Lambda }_c^{+}{\mu }^{-}\overline{\nu }$ differential decay rate
• Self-consistency and covariance of light-front quark models: testing via $P$, $V$ and $A$ meson decay constants, and $P\to P$ weak transition form factors
• Semileptonic ${\Lambda }_b\to {\Lambda }_c\ell {\bar{\nu }}_{\ell }$ Transition in Full QCD
• Light-Front Approach for Heavy Pentaquark Transitions
• Revisiting semileptonic decays of ${\Lambda }_{b(c)}$ supported by baryon spectroscopy
• First observation of the radiative decay ${\Lambda }_b^0\to \Lambda \gamma$
• Note on the Slope Parameter of the Baryonic Λ_b to Λ_c Isgur-Wise Function
• Study of the Semileptonic Decay ${\Lambda }_c^{+}\to \Lambda e^{+}{\nu }_e$
• The Light-Front Zero-Mode Contribution to the Good Current in Weak Transition
• Nonleptonic two-body weak decays of ${\Lambda }_b$ in modified MIT bag model
• Weak Decays in the light--front Quark Model
• Relativistic description of the ${\Xi }_b$ baryon semileptonic decays
• Calculation of the Isgur-Wise function from a light-front constituent quark model
• First test of Lepton Flavor Universality in the charmed baryon decays ${\Omega }_c^0\to {\Omega }^{-}{\ell }^{+}{\nu }_{\ell }$ using data of the Belle experiment
• Isgur-Wise form factors of heavy baryons within a light-front constituent quark model
• Light-front zero-mode contribution to the tensor form factors for the exclusive rare $P\to V{\ell }^{+}{\ell }^{-}$ decays
• Angular Momentum Conservation Law in Light-Front Quantum Field Theory
• Form factors of $P\to T$ transition within the light-front quark models
• Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons: an Update
• Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons
• ${\Lambda }_b\to {\Lambda }_c$ Form Factors from QCD Light-Cone Sum Rules
• Weak Radiative Decays of Anti-triplet Bottomed Baryons in Light-Front Quark Model
• Light-cone Sum Rule Analysis of Semileptonic Decays ${\Lambda }_b^0\to {\Lambda }_c^{+}{\ell }^{-}{\overline{\nu }}_{\ell }$
• Implication of $b\to c\tau \nu$ flavor anomalies on $B_s\to D_s^{\ast }\tau \nu$ decay observables
• Probing new physics in semileptonic ${\Sigma }_b$ and ${\Omega }_b$ decays
• Form-factor-independent test of lepton universality in semileptonic heavy meson and baryon decays
• Time-reversal asymmetries in ${\Lambda }_b$ semileptonic decays
• Light-front zero-mode issue on the vector meson decay constant
• Heavy quark limit in the light front quark model
• Exclusive semileptonic $B$-meson decays using lattice QCD and unitarity

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• Study of singly heavy baryon lifetimes
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• Isospin violating decays of vector charmonia
• Analysis of the semileptonic decays ${\Sigma }_b\to {\Sigma }_{c}l{\bar{\nu }}_l$, ${\Xi }_b^{\prime }\to {\Xi }_c^{\prime }l{\bar{\nu }}_l$ and ${\Omega }_b\to {\Omega }_{c}l{\bar{\nu }}_l$ in QCD sum rules