arXiv subjects

Shi-Ji Cao

Publications and source records attributed to Shi-Ji Cao.

2 recordsLinked to original sources

arXiv2026

Direct $CP$ violation in $D^\pm \to π^\pm π^+ π^-$ with $a_0^0(980)-f_0(980)$ mixing

We investigate the direct $CP$ violation in the decay $D^\pm \to π^\pm π^+ π^-$ incorporating the $a_0^0(980)$-$f_0(980)$ mixing mechanism. The integrated mixing intensities $\overline ξ_{fa}$ and $\overline ξ_{af}$ are calculated using meson masses and coupling constants extracted from various theoretical models and experimental data, yielding values of appreciable magnitude. We find that when the invariant mass of the $π^+π^-$pair lies near the $f_0(980)$ resonance, this isospin breaking mechanism can enhance the $CP$ asymmetry. The enhancement is particularly pronounced when $f_0(980)$ carries a significant $n\bar{n}$ quark component and the $f_0(980)$ and $σ(600)$ mixing angle is approximately $26^\circ$. It is emphasized that the $a_0^0(980)$-$f_0(980)$ mixing mechanism can be taken into account in both theoretical and experimental studies of $CP$ violation in $B$ or $D$ meson decays.

hep-ph↗

arXiv2024

The masses and decay widths of the $S$-wave $Λ_c\barΛ_c$ bound states

In this work, we investigate possible bound states of the $Λ_c\barΛ_c$ system in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. By numerically solving the Bethe-Salpeter equation, we confirm the existence of $Λ_c\barΛ_c$ bound states with quantum numbers $J^{PC}=0^{-+}$ and $J^{PC}=1^{--}$. We further investigate the partial decay widths of the $Λ_c\barΛ_c$ bound states into $N\bar{N}$, $D\bar{D}$, $D\bar{D}^\ast$, $D^\ast\bar{D}^\ast$, $π\barπ$, and $K\bar{K}$. Our results indicate that the decay width of the $Λ_c\barΛ_c$ bound state with $J^{PC}=1^{--}$ is much larger than that with $J^{PC}=0^{-+}$, and among their decay channels, the $D\bar{D}^\ast$ final state is the main decay mode. We suggest experiments to search for the $Λ_c\barΛ_c$ bound states in the $D\bar{D}^\ast$ final state.

hep-ph↗