arXiv subjects

Wen-Hua Qin

Publications and source records attributed to Wen-Hua Qin.

4 recordsLinked to original sources

arXiv2025

Genuine Tripartite Strong Coupling in a Superconducting-Spin Hybrid Quantum System

We demonstrate genuine tripartite strong coupling in a solid-state hybrid quantum system comprising a superconducting transmon qubit, a fixed-frequency coplanar-waveguide resonator, and an ensemble of NV$^-$ centers in diamond. Frequency-domain spectroscopy reveals a characteristic three-mode avoided crossing, indicating that single excitations are coherently shared across all three subsystems. At higher probe powers, we observe nonlinear features including multiphoton transitions and signatures of transmon-${}^{14}\mathrm{N}$ nuclear-spin interactions, highlighting the accessibility of higher-excitation manifolds in this architecture. These results establish a new regime of hybrid cavity QED that integrates superconducting and spin degrees of freedom, providing a platform for exploring complex multicomponent dynamics and developing hybrid quantum interfaces.

quant-ph↗

arXiv2024

Hunting for $X_b$ via hidden bottomonium decays $X_b\to ππχ_{bJ}$

In this work, we investigate the isospin breaking decay $X_b \to π^0χ_{bJ}$ and the isospin conserved decay $X_b \to ππχ_{bJ}$, where $X_b$ is taken to be the heavy quark flavor symmetry counterpart of $X(3872)$ in the bottomonium sector as a $B^*\bar B$ molecule candidate. Since the mass of this state may be far below the $B {\bar B}^*$ threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the $X_b$, the isospin-violating decay channel $X_b \to π^0 χ_{bJ}$ would be highly suppressed. The calculated partial width of $X_b \to ππχ_{b1}$ is found to be about tens of $\rm{keVs}$, $1\sim 2$ order(s) of magnitude larger than those of $X_b \to ππχ_{b2}$ and $X_b \to ππχ_{b0}$. Taking into account the fact that the total width of $X_b$ may be smaller than a few MeV like $X(3872)$, the calculated branching ratios $X_b\to ππχ_{b1}$ may reach to orders of $10^{-2}$, which makes it a possible channel for the experimental searching of the $X_b$.

hep-ph↗

arXiv2022

Investigations on the charmless decays of $X(3872)$ in intermediate meson loops model

The charmless decay processes of $X(3872)$ provide us a good platform to study the nature and the decay mechanism of $X(3872)$. Based on a molecular nature of $X(3872)$ as a $\bar{D}D^*$ bound state, we have investigated the charmless decays $X(3872) \to VV$ and $VP$ via intermediate $D^*{\bar D} +c.c.$ meson loops, where $V$ and $P$ stand for light vector and pseudoscalar mesons, respectively. We discuss three cases, i.e., pure neutral components ($θ=0$), isospin singlet ($θ=π/4$) and neutral components dominant ($θ= π/6$), where $θ$ is a phase angle describing the proportion of neutral and charged constituents. The proportion of neutral and charged constituent have an influence on the decay widths of $X(3872) \to VV$ and $VP$. With the coupling constant of $X(3872)$ to the $\bar{D}D^*$ channel obtained under the molecule ansatz of $X(3872)$ resonance, the predicted decay widths of $X(3872)\rightarrow VV$ are about tens of keVs, while the decay width can reach a few hundreds of keVs for $X(3872)\to VP$. The dependence of these ratios between different decay modes of $X(3872)\to VV$ and $X(3872)\to VP$ to the mixing angle $θ$ is also investigated. It is expected that the theoretical calculations here can be tested by future experiments.

hep-ph↗

arXiv2021

Production of $Z_{cs}$ in $B$ and $B_s$ decay

In the present work, we investigate the production of $Z_{cs}^+$ in $B^+$ and $B_s^0$ decay, where $Z_{cs}^+$ is assigned as a $D_s^{+} \bar{D}^{\ast0} + D_s^{\ast +}\bar{D}^0$ molecular state. By using an effective Lagrangian approach, we evaluate the branching ratio of $B^0_s\rightarrow K^- Z^+_{cs}$ and $B^+\rightarrow ϕZ^{+}_{cs}$ via the triangle loop mechanism. The estimated branching fractions of $B^0_s\rightarrow K^- Z^+_{cs}$ and $B^+\rightarrow ϕZ^{+}_{cs}$ are an order of $10^{-4} $ and $10^{-5}$, respectively. The ratio of these two branching fraction is estimated to be about 5, which indicate that the $B_s^0 \to K^\pm Z^\mp_{cs} \to K^+ K^- J/ψ$ may be a better process of searching $Z_{cs}$ and accessible for further experimental measurement of the Belle II and LHCb collaborations.

hep-ph↗