arXiv subjects

Shuge Zeng

Publications and source records attributed to Shuge Zeng.

4 recordsLinked to original sources

arXiv2026

Light baryon static properties in dispersive approach

We extend our dispersive analyses on meson static properties to those of light baryons. The formalism treats the dispersion relation, which a baryonic correlation function obeys, as an inverse problem, solve for the involved spectral density with available operator-product-expansion (OPE) inputs directly, and extract baryon static properties from the spectral density. We observe that the simultaneous implementation of the chiral-even and chiral-odd dispersive constraints unambiguously determines baryon masses and pole residues. A common set of quark and gluon condensates, which appear in OPE factorization and are universal, is found to accommodate the masses of a $\rho$ meson, a proton and a $\Delta(1232)$ baryon. The advantage of our approach over the conventional handling of QCD sum rules is advocated. This work encourages broad applications of our nonperturbative analytical method to baryon systems.

hep-ph↗

arXiv2024

The Benchmark Mode $\Omega_c \to \Omega^-\pi^+$ and Its Related Processes

The benchmark mode $\Omega_c^0\to \Omega^- \pi^+$, which receives purely factorization contribution, is of great importance among all the decay channels of $\Omega_c^0$ decays. In this work, within the framework of non-relativistic quark model (NRQM), we calculate all the 6 baryon transition form factors involving $\frac12 ^+\to \frac32 ^+$ decays. The absolute branching fractions of non-leptonic decays $\Omega_c^0\to \Omega^- \pi^+$, $\Omega_c^0\to \Omega^- \rho^+$ and $\Omega_c^0\to \Xi^- \pi^+$ as well as semi-leptonic decays $\Omega_c^0\to \Omega^- \ell^+ \nu_{\ell} \; (\ell=e,\mu)$ are calculated although they cannot be measured directly by current experiment. Based on the prediction $\mathcal{B}(\Omega_c^0\to\Omega^-\pi^+)=(3.43\pm0.48)\%$ in our work, we further predict the ratios between interested modes and the benchmark mode, giving $R(\Xi^-\pi^+)=0.16\pm0.06$, $R(\Omega^-\rho^+)=5.33\pm0.94$, $R(\Omega^- e^+\nu_e)=1.18\pm0.22$ and $R(\Omega^- \mu^+\nu_\mu)=1.11\pm0.20$. The predictions on $\Omega_c^0\to \Xi^-\pi^+$ and $\Omega_c^0\to \Omega^- e^+\nu$ agree well with recent measured ratios reported by LHCb in 2023 and ALICE in 2024, respectively.

hep-ph↗

arXiv2023

Doubly charmed baryon decays $Ξ_{cc}^{++}\toΞ_c^{(\prime)+}π^+$ in the quark model

In this work we study the doubly charmed baryon decays $Ξ_{cc}^{++}\toΞ_c^{(\prime)+}π^+$ within the framework of the non-relativistic quark model (NRQM). Factorizable amplitudes are expressed in terms of transition form factors, while nonfactorizable amplitudes arising form the inner $W$-emission are evaluated using current algebra and the pole model and expressed in terms of baryonic matrix elements and axial-vector form factors. Nonperturbative parameters are then calculated using the NRQM. They can be expressed in terms of the momentum integrals of baryon wave functions, which are in turn expressed in terms of the harmonic oscillator parameters $α_ρ$ and $α_λ$ for $ρ$- and $λ$-mode excitation. The measured ratio $R$ of the branching fraction of $Ξ_{cc}^{++}\to Ξ^{\prime +}_cπ^+$ relative to $Ξ_{cc}^{++}\to Ξ_c^+π^+$ can be accommodated in the NRQM with $α_{ρ1}$ and $α_{ρ_2}$ being in the vicinity of 0.51 and 0.19, respectively, where $α_{ρ1}$ is the $α_ρ$ parameter for $Ξ_{cc}^{++}$ and $α_{ρ2}$ for $Ξ_{c}^{(\prime)+}$. Decay asymmetries are predicted to be $-0.78$ and $-0.89$ for $Ξ_c^+π^+$ and $Ξ_c^{\prime +}π^+$ modes, respectively, which can be tested in the near future. We compare our results with other works and point out that although some other models can accommodate the ratio $R$, they tend to lead to a branching fraction of $Ξ_{cc}^{++}\to Ξ_c^+π^+$ too large compared to that inferred from the LHCb measurement of its rate relative to $Ξ_{cc}^{++}\toΛ_c^+ K^- π^+π^+$.

hep-ph↗

arXiv2022

Matter Effects of Sterile Neutrino in Light of Renormalization-Group Equations

The renormalization-group equation (RGE) approach to neutrino matter effects is further developed in this work. We derive a complete set of differential equations for effective mixing elements, masses and Jarlskog-like invariants in presence of a light sterile neutrino. The evolutions of mixing elements as well as Jarlskog-like invariants are obtained by numerically solving these differential equations. We calculate terrestrial matter effects in long-baseline (LBL) experiments, taking NOvA, T2K and DUNE as examples. In both three-flavor and four-flavor frameworks, electron-neutrino survival probabilities as well as the day-night asymmetry of solar neutrino are also evaluated as a further examination of the RGE approach.

hep-ph↗