Searcharxiv⌕ Search

arXiv subjects

Li-Fei Yang

Publications and source records attributed to Li-Fei Yang.

2 recordsLinked to original sources
arXiv2026

Contributions of the subprocesses $\rho(770,1450,1700)\to K \bar{K}$ and $\omega(782,1420,1650)\to K \bar{K}$ for the three-body decays $B\to \eta^{(\prime)} K\bar{K}$

As an extension of our prior work, we analyze the resonance contributions for the kaon pair originating from the intermediate $\rho(770)$, $\omega(782)$ and their excited states in the three-body decays $B\to \eta^{(\prime)} K\bar{K}$ within the perturbative QCD approach. The information of subprocesses $\rho(770,1450,1700)\to K\bar K$ and $\omega(782,1420,1650)\to K\bar K$ are included in the distribution amplitudes for $K\bar K$ system by using the kaon vector time-like form factors. We calculate the $CP$ averaged branching fractions and the direct $CP$ asymmetries for the relevant quasi-two-body $B$ meson decays. The branching fractions of the virtual contributions for $K\bar K$ from the Breit-Wigner formula tails of $\rho(770)$ and $\omega(782)$ for these decays are found comparable to the corresponding contributions from the resonances $\rho(1450,1700)$ and $\omega(1420,1650)$. Consequently, they constitute a significant component that should be accounted for in the considered three-body decays. All the predictions in this work are expected to be tested by the LHCb and Belle-II experiments in the future.

hep-ph↗
arXiv2024

Low-mass enhancement of kaon pairs in $B^+\to\bar{D}^{(*)0}K^+\bar{K}^0$ and $B^0\to D^{(*)-}K^+\bar{K}^0$ decays

Very recently, the Belle~II Collaboration presented a measurement for the decays $B^+\to\bar{D}^{(*)0} K^+\bar{K}^0$ and $B^0\to D^{(*)-}K^+\bar{K}^0$, the bulk of observed $m(K^+ K_S^0)$ distributions showing low-mass structures in all four channels. In this work, we study the contributions of $\rho(770,1450)^+$, $a_2(1320)^+$ and $a_0(980,1450)^+$ resonances to these decay processes. The intermediate states $\rho(770,1450)^+$ are found to dominate the low-mass distribution of kaon pairs roughly contributing to half of the total branching fraction in each of the four decay channels. The contribution of the tensor $a_2(1320)^+$ meson is found to be negligible. Near the threshold of the kaon pair, the state $a_0(980)^+$ turns out to be much less important than expected, not being able to account for the enhancement of events in that energy region observed in the $B^+\to\bar{D}^{(*)0} K^+\bar{K}^0$ decays. Further studies both from the theoretical and experimental sides are needed to elucidate the role of the non-resonant contributions governing the formation of $K^+\bar{K}^0$ pairs near their threshold in these decay processes.

hep-ph↗