论文标题
di-$ j/ψ$频谱中结构的解释
Interpretation of structure in the di-$J/ψ$ spectrum
论文作者
论文摘要
LHCB实验观察到的6.9和7.2 GEV观察到的di-$ j/ψ$质谱的结构用$ j^{pc} = 0^{++} $以及$ 2^{++} $在$ cc $ diquark和a $ \ bar c \ bar c $ condiquark之间使用$ j^{++} $和$ 2^{++} $ ressonances，使用$ cc $群众。 6.9 GEV左右的主要峰可能以$ 0^{++}（2s）$状态为主导，这是$ cc $ - $ \ bar c \ bar c $ tetraquark的径向激发，我们预计我们预计$ 6.871 \ pm pm 0.025 $ gev。大约6.75 GEV的倾角归因于\ swave \ di-$χ_{c0} $通道的打开，而dip of 7.2 GEV的倾角可能与di-$η_c（2s）$或$ $ $ $或$ en_c（2S）$或$ξ_{cc} {cc} \ bar eCc {cc {cc {cc} $ Channel的打开相关。 di-$ j/ψ$结构的低质量部分似乎需要与预测的$ 2^{++}（1s）$状态一致的宽泛共振，而$ m _ {\ rm Inv} = 6400 $ MEV，质量不变质量。讨论了对$ bb \ bar b \ b $ tetraquarks的影响。
Structure in the di-$J/ψ$ mass spectrum observed by the LHCb experiment around 6.9 and 7.2 GeV is interpreted in terms of $J^{PC}=0^{++}$ and $2^{++}$ resonances between a $cc$ diquark and a $\bar c \bar c$ antidiquark, using a recently confirmed string-junction picture to calculate tetraquark masses. The main peak around 6.9 GeV is likely dominated by the $0^{++}(2S)$ state, a radial excitation of the $cc$-$\bar c \bar c$ tetraquark, which we predict at $6.871\pm 0.025$ GeV. The dip around 6.75 GeV is ascribed to the opening of the \Swave\ di-$χ_{c0}$ channel, while the dip around 7.2 GeV could be correlated with the opening of the di-$η_c(2S)$ or $Ξ_{cc} \bar Ξ_{cc}$ channel. The low-mass part of the di-$J/ψ$ structure appears to require a broad resonance consistent with a predicted $2^{++}(1S)$ state with invariant mass around $M_{\rm inv} = 6400$ MeV. Implications for $bb \bar b \bar b$ tetraquarks are discussed.
