AI 中文总结
本研究在√s=10.58GeV下分析e⁺e⁻→HHγ过程，结合X(6900)的张量贡献，发现连续态与X(6900)的干涉会显著修改不变质量分布，J/ψJ/ψγ道共振结构明显，η_cη_cγ道产生率极低，凸显振幅层级处理X(6900)的重要性。
AI 中文摘要
我们研究质心系能量√s=10.58GeV下的辐射双粲偶素产生过程e⁺e⁻→HHγ，其中H为J/ψ和η_c，包含来自全粲态X(6900)的可能张量贡献。非共振振幅在色单态非相对论量子色动力学框架内计算，而J^PC=2^{++}的共振态与连续态相干结合。我们发现连续态与共振态的干涉会显著修改M_HH≈M_X附近的不变质量分布，J/ψJ/ψγ道呈现明显的依赖相位的共振结构，近共振截面为0.038–0.111fb；相比之下，η_cη_cγ道以连续态为主，仅表现出局域化的干涉效应且产生率被极度压低，导致其实验观测极具挑战性。这些道依赖的特征源于不同的有效衰变结构，证明了对X(6900)贡献进行振幅层级处理的重要性。
英文摘要
We study radiative double-charmonium production, $e^+e^-\to HHγ$ with $H=J/ψ$ and $η_c$, at $\sqrt{s}=10.58~{\rm GeV}$, including a possible tensor contribution from the fully charmed state $X(6900)$. The nonresonant amplitudes are calculated within the color-singlet non-relativistic QCD framework, while the $J^{PC}=2^{++}$ resonance is combined coherently with the continuum. We find that continuum--resonance interference significantly modifies the invariant-mass distributions near $M_{HH}\simeq M_X$. The $J/ψJ/ψγ$ channel exhibits a pronounced phase-dependent resonant structure, with a near-resonance cross section of $0.038$--$0.111~{\rm fb}$. In contrast, the $η_cη_cγ$ channel is continuum dominated and shows only a localized interference effect with an extremely suppressed production rate, rendering its experimental observation extremely challenging. These channel-dependent features arise from the different effective decay structures and demonstrate the importance of an amplitude-level treatment of the $X(6900)$ contribution.
Comments21 pages, 3 figures
