arXiv subjects

Sheng-Lin Liu

Publications and source records attributed to Sheng-Lin Liu.

5 recordsLinked to original sources

arXiv2026

New $CP$ sum rules from exact $U$-spin degeneracy

We propose a new class of $CP$ sum rules in the $U$-spin limit, based on the observation that the weak phase in the Standard Model can be removed in the degenerate limit $m_d=m_s$. Unlike previous $U$-spin analyses formulated at the amplitude level, our sum rules are expressed directly in terms of decay widths. They apply to matched partial waves, spin observables, and angular moments and include nonpairwise cases beyond the usual single-insertion $d\leftrightarrow s$ relation.

hep-ph↗

arXiv2026

Spin-flavor entanglement in $\Lambda_b \to \Lambda D$ and weak phase extraction

We identify a new spin-flavor entanglement structure in $\Lambda_b\to\Lambda D$ decays, formed by the correlation between the $\Lambda$ spin and the $D$ flavor states ($D=D^0,\overline D^0,D_1,D_2$). The entanglement information is encoded in the decay rates and Lee-Yang parameters of the four neutral-$D$ modes. We then show that the same spin-flavor structure provides a new method to determine the weak phase $\gamma$, a key angle of the Cabibbo-Kobayashi-Maskawa unitarity triangle. We find that the experimental uncertainty scales as $\sigma_\gamma\propto 1/{\cal C}$, where ${\cal C}$ is the Wootters concurrence, thereby quantitatively relating the precision of the weak-phase extraction to the amount of spin-flavor entanglement.

hep-ph↗

arXiv2026

Puzzles in charmed baryon semileptonic decays with $SU(3)_F$ flavor symmetry and lattice inputs

Recent measurements of charmed-baryon semileptonic decays signal large tensions between experiment and theory, including $SU(3)_F$ analyses and lattice-quantum chromodynamics simulations. Possible sources of the discrepancy include the experimental normalization mode $\Xi_c^0 \to \Xi^- \pi ^+$. Using lattice-QCD inputs in an $SU(3)_F$ analysis including first-order symmetry breaking, we predict ${\cal B}( \Xi_c^+ \to \Sigma^0 \ell^+ \nu_\ell ) / {\cal B}( \Xi_c^+ \to \Xi^0 \ell^+ \nu_\ell )=(2.6\pm0.3)\%, $ and ${\cal B}( \Xi_c^+ \to \Lambda \ell^+ \nu_\ell )/{\cal B}( \Xi_c^+ \to \Xi^0 \ell^+ \nu_\ell )=(1.1\pm0.1)\%, $ with $\ell^+=(e^+,\mu^+)$. These ratios provide normalization-independent tests and may help clarify the origin of the present tension.

hep-ph↗

arXiv2025

Two-body charmed baryon nonleptonic weak decays with decuplet baryon involving SU(3) breaking effects

We study the singly charmed baryon two-body decays of $\mathbf{B}_c \rightarrow \mathbf{B}_D P$ under $SU(3)_{F}$ flavor symmetry, where ${\bf B}_{c}$ refers to anti-triplet singly charmed baryons, and ${\bf B}_{D}$ and $P$ denote decuplet baryons and pseudoscalar mesons, respectively. Compared to the literature, we adopt a concise and reasonable treatment of the $SU(3)$ flavor symmetry breaking, by considering the final-state mass dependence of partial waves. With 4 real parameters in total and 9 experimental data points, we achieve a minimal $\chi^2/\text{d.o.f.} $ value of $ 1.46$, providing a satisfactory explanation to the experiment results. We evaluate the branching ratios and Lee-Yang parameters suggesting the absence of the strong phase in $\mathbf{B}_c \rightarrow \mathbf{B}_D P$, along with an unusual positive decay asymmetry $\alpha\,(\Xi_{c}^{0}\rightarrow \Omega^{-}K^{+})$. The predicted results of large $SU(3)_{F}$ breaking effects in $\mathbf{B}_c \rightarrow \mathbf{B}_D P$ can be verified in the further research by the experiments at BESIII, Belle-II and LHCb.

hep-ph↗

arXiv2024

Nonleptonic three-body charmed baryon weak decays with H(15)

We study the nonleptonic three-body charmed baryon weak decays of $\mathbf{B}_{c}\rightarrow\mathbf{B}_{n}PP^{\prime}$ under the $SU(3)_{F}$ flavor symmetry, where $\mathbf{B}_{c}$ denotes the anti-triplet charmed baryon, comprising $(\Xi^{0}_{c},-\Xi^{+}_{c},\Lambda^{+}_{c})$, and $\mathbf{B}_{n}$ and $P(P^{\prime})$ represent octet baryon and pseudoscalar meson states, respectively. In addition to 12 parameters from the contributions of the color-antisymmetric part of the effective Hamiltonian, denoted as $H(\bar{\mathbf{6}})$, there are 4 parameters from the color-symmetric one, $H(\mathbf{15})$, which were not included in the previous study. With 16 parameters in total and 28 experimental data points, we obtain the minimal $\chi^2$ over degree of freedom of $\chi^{2}/d.o.f=1.5$, which is a great improvement comparing to that without $H(\mathbf{15})$. With the better fitting values, we evaluate the branching ratios and up-down asymmetries of $\mathbf{B}_{c}\rightarrow\mathbf{B}_{n}PP^{\prime}$, which present some interesting results such as $\mathcal{B}\,(\Lambda^{+}_{c}\rightarrow(\Xi(1690)^{0}\rightarrow\Sigma^{+}K^{-})\,K^{+})\equiv(1.5\pm0.4)\times10^{-3}$ and potential $SU(3)$ breaking effects in $\Xi^{+}_{c}\rightarrow p\pi^{+}K^{-}$ and $\Lambda^{+}_{c}\rightarrow \Sigma^{+}\pi^{-}K^{+}$ to be verified by the experiments at BESIII, Belle-II and LHCb.

hep-ph↗