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arXiv · 1307.6654

Estimating the mass of the hidden charm $1^+(1^{+})$ tetraquark state via QCD sum rules

Cong-Feng Qiao·Liang Tang
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Abstract

By using QCD sum rules, the mass of the hidden charm tetraquark $[cu][\bar{c}\bar{d}]$ state with $I^{G} (J^{P}) = 1^+ (1^{+})$ (HCTV) is estimated, which presumably will turn out to be the newly observed charmonium-like resonance $Z_c^+(3900)$. In the calculation, contributions up to dimension eight in the operator product expansion(OPE) are taken into account. We find $m_{1^+}^c = (3912^{+306}_{-153}) \, \text{MeV}$, which is consistent, within the errors, with the experimental observation of $Z_c^+(3900)$. Extending to the b-quark sector, $m_{1^+}^b = (10561^{+395}_{-163}) \,\text{MeV}$ is obtained. The calculational result strongly supports the tetraquark picture for the "exotic" states of $Z_c^+(3900)$ and $Z_b^+(10610)$.

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Cong-Feng Qiao, Liang Tang. 2014-10-27. Estimating the mass of the hidden charm $1^+(1^{+})$ tetraquark state via QCD sum rules. https://doi.org/10.1140/epjc%2Fs10052-014-3122-x

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