arXiv subjects

Ke-Sheng Huang

Publications and source records attributed to Ke-Sheng Huang.

4 recordsLinked to original sources

arXiv2026

Semileptonic Decay of $Λ_b \rightarrow N(1520)\ell^-\barν_{\ell}$ from QCD Light-cone Sum Rules

We investigate the complete set of vector and axial-vector form factors for the charged-current transition $Λ_b^0\to N(1520)^+$ using QCD light-cone sum rules (LCSRs) based on the light-cone distribution amplitudes (LCDAs) of the $Λ_b$ baryon, with the hard-scattering kernels evaluated at tree level. In the hadronic representation of the correlation function, we include the pole contributions of both the negative-parity $N(1520)$, with $J^P=3/2^-$, and the positive-parity $N(1720)$, with $J^P=3/2^+$. By matching a selected set of Lorentz structures, we derive sum rules that separate the $N(1520)$ contribution from the $N(1720)$ contribution within the adopted two-pole hadronic ansatz. After extrapolating the large-recoil LCSR results over the physical $q^2$ region using a pole-improved $z$ expansion truncated at linear order, we predict the differential branching fractions, the lepton forward-backward asymmetry, the charged-lepton polarization, and the $N(1520)$ polarization in $Λ_b^0\to N(1520)^+\ell^-\barν_{\ell}$ ($\ell=e,μ,τ$). The corresponding total branching fractions are $\mathcal{B}_{e,μ,τ} =(12.4\pm10.5,\,12.4\pm10.5,\,5.0\pm4.3)\times10^{-5}$. Within the stated approximations, these results may serve as theoretical benchmarks for future experimental studies of this channel.

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arXiv2024

Transition form factors of the $Λ_b \rightarrow Λ(1520)$ in QCD light-cone sum rules

In this work, we investigate the transition form factors for $Λ_b\rightarrow{Λ(1520)}$ within the framework of light-cone sum rules (LCSR), using the light-cone distribution amplitudes (LCDAs) of the $Λ_b$-baryon. In the hadronic representation of the correlation function, we carefully select the appropriate Lorentz structures and isolate the contributions from both the $Λ(1520)(J^P=(3/2)^-)$ and the $Λ(1890)(J^P=(3/2)^+)$, ensuring that the form factors for $Λ_b\rightarrow{Λ(1520)}$ can be calculated unambiguously. We also provide predictions for various physical observables in the decay $Λ_b\rightarrow{Λ(1520)}l^+l^-$, including the differential branching fraction, the lepton-side forward-backward asymmetry, the longitudinal polarization fraction, and the CP-averaged normalized angular observable. Our prediction for the differential branching fraction of $Λ_b\rightarrow{Λ(1520)}μ^+μ^-$ is in good agreement with the LHCb measurement within the uncertainties.

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arXiv2023

$Λ_b \to p, N^\ast(1535)$ Form Factors from QCD Light-Cone Sum Rules

In this work we calculate the transition form factors of $Λ_b$ decaying into proton and $N^*(1535)$ ($J^P={1/2}^+$ and ${1/2}^-$ respectively), within the framework of light-cone sum rules with the distribution amplitudes (DAs) of $Λ_b$-baryon. In the hadronic representation of the correlation function, we have isolated both the proton and the $N^*(1535)$ states so that the $Λ_b \rightarrow p, N^*(1535)$ form factors can be evaluated simultaneously. Due to the less known properties of baryons, we investigate three interpolating currents of the light baryons and five parametrization models for DAs of $Λ_b $. Numerically, our predictions on the $Λ_b \rightarrow p$ form factors and the branching fractions of $Λ_b\to p\ell ν$ from the Ioffe or the tensor currents are consistent with the Lattice simulation and the results from the light-baryon sum rules, as well as the experimental data of $Br(Λ_b^0\to pμ^-\barν)$. The predictions on the form factors of $Λ_b \rightarrow N^*(1535)$ are very sensitive to the choice of the interpolating currents so that the relevant measurement could be helpful to clarify the properties of baryons.

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arXiv2022

$Λ_b \to Λ_c$ Form Factors from QCD Light-Cone Sum Rules

In this work, we calculate the transition form factors of $Λ_b$ decaying into $Λ_c$ within the framework of light-cone sum rules with the distribution amplitudes (DAs) of $Λ_b$-baryon. In the hadronic representation of the correlation function, we have isolated both the $Λ_c$ and the $Λ_c^*$ states so that the $Λ_b \rightarrow Λ_c$ form factors can be obtained without ambiguity. We investigate the P-type and A-type current to interpolate the light baryons for a comparison since the interpolation current for the baryon state is not unique. We also employ three parametrization models for DAs of $Λ_b $ in the numerical calculation. We present the numerical predictions on the $Λ_b \rightarrow Λ_c$ form factors and the branching fractions, the averaged forward-backward asymmetry , the averaged final hadron polarization and the averaged lepton polarization of the $Λ_b \to Λ_c \ellμ$ decays, as well as the ratio of branching ratios $R_{Λ_c}$, and the predicted $R_{Λ_c}$ can be consistent with the LHCb data.

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