arXiv subjects

Hao-Nan Wang

Publications and source records attributed to Hao-Nan Wang.

5 recordsLinked to original sources

arXiv2026

Role of $K^*_0(700)$ exchange in the $p \bar{p} \to Λ\barΛ$ reaction

Based on the effective Lagrangian approach, we investigate the $p \bar{p} \to Λ\barΛ$ reaction. Within this framework, we provide a dynamical explanation by analyzing its total and differential cross sections, as well as the polarization of the produced $Λ$ hyperon. Incorporating the $t$-channel exchange of the scalar $K^*_0(700)$ and pseudoscalar $K$ mesons, complemented by an $s$-channel contribution from the vector excited state, we can reproduce the current experimental data fairly well in a wide energy region. Compared to the conventional $K$ and $K^*(892)$ mesons exchange, the $K^*_0(700)$ meson exchange plays a more essential role in simultaneously capturing the observed features of the total and differential cross sections. The introduction of the vector $s$-channel resonance improves the description of the spin observables. This work gives a perspective to inspect the role of $K^*_0(700)$ and serves as a test to search for the resonances in the reaction $p \bar{p} \to Λ\barΛ$ at threshold.

hep-ph↗

arXiv2024

Analysis of $B_s^0 \to X(3872) [ψ(2S)] π^+π^- (K^+ K^-)$ decays

We have phenomenologically investigated the decays $B_s^0 \to X(3872) π^+π^- (K^+ K^-)$ and $B_s^0 \to ψ(2S) π^+ π^- (K^+K^-)$. In our analysis, the scalar meson $f_0(980)$ is formed through the final state interactions of coupled channels $ππ$ and $K\bar{K}$. Our findings indicate that the $π^+π^-$ invariant mass distribution of the $B_s^0 \to ψ(2S)π^+π^-$ decay can be accurately reproduced. Furthermore, we have explored the $π^+π^- (K^+ K^-)$ invariant mass distribution of the $B_s^0 \to X(3872) π^+π^- (K^+ K^-)$ decay, accounting for the different production mechanisms between $X(3872)$ and $ψ(2S)$, up to a global factor. It is found that the production rates for $X(3872)$ and $ψ(2S)$ are much different, which indicates that the structure of $X(3872)$ is more complicated than the $ψ(2S)$, which is a conventional $c\bar{c}$ state. Additionally, we have considered the contributions from $f_0(1500)$ to $π^+π^-$ and the $ϕ$ meson to $K^+ K^-$ in our analysis. Utilizing the model parameters, we have calculated the branching fraction of $B_s^0 \to X(3872) K^+ K^-$, and anticipate that the findings of our study can be experimentally tested in the future.

hep-ph↗

arXiv2022

Nature of $X(3872)$ in $B^0 \to K^0 X(3872)$ and $B^+ \to K^+ X(3872)$ decays

We investigate the decays of $B^0 \to K^0 X(3872)$ and $B^+ \to K^+ X(3872)$ based on the picture where the $X(3872)$ resonance is strongly coupled to the $D\bar{D}^* + c.c.$ channel. In addition to the decay mechanism where the $X(3872)$ resonance is formed from the $c\bar{c}$ pair hadronization with the short-distance interaction, we have also considered the $D\bar{D}^*$ rescattering diagrams in the long-distance scale, where $D$ and $\bar{D}^*$ are formed from $c$ and $\bar{c}$ separately. Because of the difference of the mass thresholds of charged and neutral $D\bar{D}^*$ channels, and the rather narrow width of the $X(3872)$ resonance, at the $X(3872)$ mass, the loop functions of $D^0\bar{D}^{*0}$ and $D^+\bar{D}^{*-}$ are much different. Taking this difference into account, the ratio of $\mathcal{B}[B^0\to K^0X(3872)]/\mathcal{B}[B^+ \to K^+ X(3872)] \simeq 0.5$ can be naturally obtained. Based on this result, we also evaluate the decay widths of $B_s^0 \to η(η') X(3872)$. It is expected that future experimental measurements of these decays can be used to elucidate the nature of the $X(3872)$ resonance.

hep-ph↗

arXiv2022

Further understanding the nature of $a_0(1710)$ in the $D^+_s \to π^0 K^+ K^0_S$ decay

Based on our previous work about the role of $a_0(1710)$ in the $D_s^+\toπ^+K_S^0K_S^0$ decay [Phy. Rev. D 105, 116010 (2022)], we perform a further theoretical study of $a_0(1710)^+$ in the process $D^+_s \to π^0 a_0(1710)^+ \to π^0 K^+ K^0_S$. In addition to $a_0(1710)$, the contributions of $K^*$ and $a_0(980)$ are also taken into account. Firstly, we consider the contributions from the tree diagrams of $K^{*+} \to K^+π^0$ and $\bar{K}^{*0} \to π^0 \bar{K}^0$. Secondly, we describe the final state interaction of $K\bar{K}$ in the chiral unitary approach to study the contribution of $a_0(980)$, while the $a_0(1710)$ state is dynamically generated from the $K^*\bar{K}^*$ interaction, and then decays into $K^+\bar{K}^0$. Since the final $K^+ K_S^0$ state is in pure isospin $I=1$, the $D_s^+\toπ^0K^+K_s^0$ decay is an ideal process to study the $a_0(1710)^+$ and $a_0(980)^+$ resonances. Based on our theoretical calculations, it is found that the recent experimental measurements on the $K^+K^0_S$, $π^0K^+$, and $π^0 K_S^0$ invariant mass distributions can be well reproduced, which supports the molecular $K^*\bar{K}^*$ nature of the scalar $a_0(1710)$ resonance.

hep-ph↗

arXiv2022

Theoretical study on the contributions of $ω$ meson to the $X(3872) \to J/ψπ^+π^-$ and $J/ψπ^+π^-π^0$ decays

With the newly measurements of $X(3872) \to J/ψπ^+π^-$ from LHCb Collaboration, in addition to the dominant contribution from the $ρ^0$ meson, we perform a theoretical study on the contribution of $ω$ meson in the $X(3872) \to J/ψπ^+π^-$ and $X(3872)\to J/ψπ^+π^-π^0$ processes. It is found that the recent experimental measurements on the $π^+ π^-$ invariant mass distributions can be well reproduced, and the ratio of the couplings between $X(3872) \to J/ψρ^0$ and $X(3872) \to J/ψω$ is also evaluated. Within the parameters extracted from the $π^+ π^-$ invariant mass distributions of the $X(3872) \to J/ψπ^+π^-$ process, the branching fractions of the $X(3872) \to J/ψω$ channel relative to that of the $X(3872) \to J/ψπ^+π^-π^0$ channel and the $π^+ π^- π^0$ invariant mass distributions of the $X(3872) \to J/ψπ^+π^-π^0$ decay are calculated, which gives a hint for the further high-statistic experiment.

hep-ph↗