arXiv subjects

Ying-Xin Lai

Publications and source records attributed to Ying-Xin Lai.

4 recordsLinked to original sources

arXiv2026

Topological diagrams of $Ω^0_c$ decays in the $SU(3)_F$ limit

The $Ω^0_c$ baryon is unique among charmed sextet baryons because it decays through the weak interaction. In this work, we investigate the topological amplitudes of $Ω_c^0$ decays in the $SU(3)_F$ limit. The complete set of tree- and penguin-induced diagrams contributing to $Ω_c^0$ decays into decuplet and octet baryons is presented. The linear relations between the topological amplitudes and the $SU(3)$ irreducible amplitudes are derived through tensor analysis. Several isospin relations are obtained, and additional relations are derived to test the Körner-Pati-Woo theorem.

hep-ph↗

arXiv2026

CP asymmetries in $D\to K^0_{S,L}P$ and $D\to K^0_{S,L}V$ decays

$D$ meson decays into neutral kaons involve both Cabibbo-favored and doubly Cabibbo-suppressed amplitudes as well as final-state kaon mixing, providing abundant sources of CP violation. In this work, we analyze CP asymmetries in the $D\to K^0_{S,L}P$ and $D\to K^0_{S,L}V$ decays, where $P$ and $V$ denote pseudoscalar and vector mesons respectively. The formulas of the time-dependent and time-integrated CP asymmetries in these modes are derived, in which the $D^0-\overline D^0$ mixing effects and the $K^0_L$ modes are considered for the first time. The hadronic parameters that determine CP asymmetries are extracted by the global fit of branching fractions within the topological diagram approach. A significant result is that the tension between theoretical predictions and experimental data for the $K_S^0-K_L^0$ asymmetries in $D^0\to K_{S,L}^0ω$ and $D^0\to K_{S,L}^0ϕ$ modes is mitigated. The CP-violating effects arising from the interference between Cabibbo-favored and doubly Cabibbo-suppressed amplitudes with neutral kaon mixing could reach to $\mathcal{O}(10^{-3})$ order in the $D^+\to K^0_Sπ^+$, $D^+_s\to K^0_SK^+$, $D^0\to K^0_Sρ^0$, and $D^0\to K^0_Sϕ$ modes. The difference between the CP asymmetries in the $D^+\to K^0_Sπ^+$ and $D^+_s\to K^0_SK^+$ modes will be available on LHCb and Belle II in the near future.

hep-ph↗

arXiv2026

From topological amplitudes to rescattering dynamics in charmed baryon decays

Charmed baryon decays play an important role in studying the weak and strong interactions, which have been studied in the rescattering dynamics and topological diagram approach. In this work, we establish a theoretical framework to correlate the topological diagram at quark level and rescattering dynamics at hadron level. Note that the chiral Lagrangian involving octet baryons is constructed via (1,1)-rank octet tensors, while topological diagrams are constructed by 3-rank octet tensors. We propose that, the (1,1)-rank amplitudes, which are linear combinations of topological diagrams, will be a bridge between topological amplitudes and rescattering dynamics. The possible meson-meson or meson-baryon coupling configurations are constructed via tensor contractions. The rescattering amplitudes derived from topological amplitudes are consistent with those derived directly from the chiral Lagrangian. The $u$-, $t$-, and $s$-channel rescattering amplitudes contributing to each (1,1)-rank amplitudes in the $SU(3)_F$ limit are derived. Isospin sum rules for all isospin systems in $ B_{c\overline{3}}\to B_8P$ decays are checked in terms of rescattering amplitudes. The rescattering amplitudes contributing to penguin diagrams are found to be comparable to those contributing to tree diagrams, indicating potential observable $CP$ violation in charmed baryon decays. Furthermore, it is found that the Körner-Pati-Woo theorem is not consistent with the rescattering dynamics. The proof of the Körner-Pati-Woo theorem is questionable when the color changes of quarks arising from gluons are considered. We suggest precisely measuring the branching fraction of the $Λ^+_c\to Σ^+K^0_S$ mode on Belle (II) to test the Körner-Pati-Woo theorem.

hep-ph↗

arXiv2025

Topological diagrams of doubly charmed baryon decays in the $SU(3)_F$ limit

The doubly charmed baryon was first observed by LHCb via the non-leptonic decay $Ξ_{cc}^{++}\to Λ^+_cK^-π^+π^+$ in 2017. Subsequently, ongoing efforts have been made to identify other doubly charmed baryons. However, there is no systematic analysis of the topological decomposition for non-leptonic decays of doubly charmed baryons. In this work, we study the topological amplitudes of doubly charmed baryon decays in the $SU(3)_F$ limit. Tree- and penguin-induced topological diagrams for the $\mathcal{B}_{cc}\to \mathcal{B}_c M$ and $\mathcal{B}_{cc}\to \mathcal{B} D$ decays are presented. The linear relations between the topological amplitudes and the $SU(3)$ irreducible amplitudes are derived through tensor contraction and $SU(3)$ decomposition. The magnitude pattern of the topological diagrams is analyzed in the rescattering dynamics and the large $N_c$ expansion. In addition, some amplitude relations are derived to test the Körner-Pati-Woo theorem in the isospin limit.

hep-ph↗