AI 中文总结
该研究在重手征微扰论中计算了D*和B*的自旋依赖电磁极化率，阐明了Dπ阈值效应的自旋依赖性，为格点QCD研究提供基准。
AI 中文摘要
我们在重手征微扰论中，研究了重矢量介子D*和B*的自旋依赖电磁极化率，计算精度达到O(p³)。针对自旋1靶的实光子康普顿散射，采用12个元素的张量基，确定了2个标量、4个矢量和6个张量极化率。我们分别从已测量的D*宽度和格点量子色动力学（lattice-QCD）计算中获取粲区和底区的轴耦合，并在非相对论组分夸克模型中估计磁耦合。在粲区，带电Dπ阈值的邻近性产生强非解析的Pφ圈贡献，对多个\bar D^{*0}极化率产生大的实部，对带电Dπ通道开放的D^{*-}产生可观的虚部。E1E1型极化率比M1M1型极化率增强得多，这与 pion云磁耦合的速度压低一致。B*则无类似增强：玻恩项主导磁极化率，无玻恩贡献的矢量极化率由反常极点主导。这些结果阐明了Dπ阈值效应的自旋依赖性，为未来格点量子色动力学研究提供基准。
英文摘要
We investigate the spin-dependent electromagnetic polarizabilities of the heavy vector mesons \(D^*\) and \(B^*\) in heavy meson chiral perturbation theory up to \(\mathcal O(p^3)\). Using a twelve-element tensor basis for the real-photon Compton scattering on a spin-1 target, we determine two scalar, four vector and six tensor polarizabilities. We take the charm- and bottom-sector axial couplings from the measured \(D^*\) width and lattice-QCD calculations, respectively, and estimate the magnetic couplings in the nonrelativistic constituent-quark model. In the charm sector, the proximity of the charged \(Dπ\) thresholds generates strongly nonanalytic \(Pϕ\)-loop contributions, producing large real contributions to several \(\bar D^{*0}\) polarizabilities and sizable imaginary parts for \(D^{*-}\), whose charged \(Dπ\) channel is open. The \(E1E1\)-type polarizabilities are enhanced much more strongly than their \(M1M1\)-type counterparts, consistent with the velocity suppression of the pion-cloud magnetic coupling. No analogous enhancement occurs for \(B^*\): the Born terms govern the magnetic polarizabilities, and the anomaly poles dominate the vector polarizabilities that receive no Born contribution. These results resolve the spin dependence of the \(Dπ\) threshold effect and provide benchmarks for future lattice-QCD studies.
Comments20 pages, 1 figure, 6 tables
