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arXiv 1006.4880hep-phhep-ex
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重-轻介子和夸克偶素的超精细分裂

The Hyperfine Splittings in Heavy-Light Mesons and Quarkonia

A. M. Badalian, B. L. G. Bakker, I. V. Danilkin

摘要:

超精细分裂(HFS)是在考虑相对论修正的场相关器方法中计算的。如果在微扰自旋-自旋势中采用普适耦合$B_q$,则底鎓和$B_q$(q=n,s)介子的HFS与实验完全一致。它给出了$M(B^*)-M(B)=45.7(3)$ MeV,$M(B_s^*)-M(B_s)=46.7(3)$ MeV($n_f=4$),而在底鎓中,$n_f=4$得到了$Δ_{HF}(b\bar b)=M(Υ(9460))-M(η_b(1S))=63.4$ MeV,$n_f=5$得到了71.1 MeV;后者与最近的BaBar数据一致。对于未观察到的激发态,我们预测$M(Υ(2S))-M(η_b(2S))=36(2)$ MeV,$M(Υ(3S))-M(η(3S))=28(2)$ MeV,以及$M(B_c^*)=6334(4)$ MeV,$M(B_c(2S))=6868(4)$ MeV,$M(B_c^*(2S))=6905(4)$ MeV。预计$D(2^3S_1)-D(2^1S_0)$、$D_s(2^3S_1)-D_s(2^1S_0)$之间的质量分裂为$\sim 70$ MeV,其显著小于其他几项研究。

英文摘要:

Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the $B_q$ (q=n,s) mesons are shown to be in full agreement with experiment if a universal coupling $α_{HF}=0.310$ is taken in perturbative spin-spin potential. It gives $M(B^*)-M(B)=45.7(3)$ MeV, $M(B_s^*)-M(B_s)=46.7(3)$ MeV ($n_f=4$), while in bottomonium $Δ_{HF}(b\bar b)=M(Υ(9460))-M(η_b(1S))=63.4$ MeV for $n_f=4$ and 71.1 MeV for $n_f=5$ are obtained; just latter agrees with recent BaBar data. For unobserved excited states we predict $M(Υ(2S))-M(η_b(2S))=36(2)$ MeV, $M(Υ(3S))-M(η(3S))=28(2)$ MeV, and also $M(B_c^*)=6334(4)$ MeV, $M(B_c(2S))=6868(4)$ MeV, $M(B_c^*(2S))=6905(4)$ MeV. The mass splittings between $D(2^3S_1)-D(2^1S_0)$, $D_s(2^3S_1)-D_s(2^1S_0)$ are predicted to be $\sim 70$ MeV, which are significantly smaller than in several other studies.

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