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Tian-Liang Feng

Publications and source records attributed to Tian-Liang Feng.

3 recordsLinked to original sources

Probing direct $CP$ violation in $Λ_b^0 \to P_c^+ h^-$ $(h=π,K)$ with final-state rescattering

The LHCb Collaboration recently reported a measurement of the difference in direct CP asymmetries for the decays $Λ_b^0 \to J/ψ\, p \, h^-$ (with $h = K, π$), offering new experimental constraints on the decay dynamics of heavy baryons into charmonium final states. Inspired by these findings, we explore the branching ratios and direct CP violations for the decays $Λ_b^0 \to P_c^+(4312, 4440, 4457)\,h^-$ within the framework of final-state rescattering. Our analysis indicates that the branching fractions for $Λ_b^0 \to P_c^+ π^-$ lie around the $10^{-6}$ level, with the corresponding direct CP asymmetries approaching approximately $1\%$. In contrast, the direct CP violation for the decay $Λ_b^0 \to P_c^+ K^-$ is found to be very small, while its branching ratios show a strong dependence on the spin assignments of the $P_c$ states. These predictions may provide useful guidance for more precise CP measurements and amplitude analyses in the $P_c$ region in future experiments.

hep-ph

Study of $CP$ violation in $Λ_b^0/Ξ^-_b\rightarrow Λ(1520)M$ decays with the final-state rescattering mechanism

Recently, the LHCb collaboration reported the first observation of $CP$ violation in baryon decays, with a significance of more than $5σ$. This strongly motivates us to investigate the $CP$ violation in more baryon decay processes. In this work, we employ the final-state rescattering mechanism with introducing two model parameters, $Λ_{charm}$ and $Λ_{charmless}$, and calculate two-body non-leptonic baryon decays $Λ^0_b \rightarrow Λ(1520)\,π^0/κ(700)/f_0(500, 980)/ρ^0/K^{*0}/ϕ$ and $Ξ^-_b \rightarrow Λ(1520)\,K^-$. Consequently, we evaluate the corresponding branching ratios, $CP$ asymmetries, and interference effects between different decay amplitudes. Our theoretical predictions for certain decay channels are in good agreement with current experimental measurements, while the remaining processes--particularly the remarkably large $CP$ violation observable revealed by the kinematic analysis are expected to be tested in future experiments.

hep-ph

Study of $CP$ violation in $Λ_b^0\rightarrow N^*M$ decays with the final-state rescattering mechanism

In this work, we investigate the charmless non-leptonic two-body $Λ_b$ decays within the framework of final-state rescattering mechanism. In contrast to the Cutkosky cutting method, we compute both the absorptive and dispersive parts of the hadronic rescattering triangle diagrams. Based on the established formalism, we analyze the $Λ_b \to N^*(1535,1520)M$ decay processes with $M =K_S, K^*_0(700)$, $f_0(500,980), ρ(770), \bar{K}^{*0}$, $ϕ$, and predict various physical observables, such as their branching ratios, direct and partial-wave $CP$ asymmetries, as well as decay asymmetry parameters. These two-body decay processes are expected to contribute primarily to the subsequent four-body decay channels, such as $Λ_b^0 \to p\,π^-\,π^+\,π^-$, whose $CP$ asymmetry measurements will be accessible at the LHCb experiment.

hep-ph