# Vector tetraquark state candidates: Y(4260 / 4220), Y(4360 / 4320), Y(4390) and Y(4660 / 4630)

The European Physical Journal C, Jun 2018

In this article, we construct the $$C \otimes \gamma _\mu C$$ and $$C\gamma _5 \otimes \gamma _5\gamma _\mu C$$ type currents to interpolate the vector tetraquark states, then carry out the operator product expansion up to the vacuum condensates of dimension-10 in a consistent way, and obtain four QCD sum rules. In calculations, we use the formula $$\mu =\sqrt{M^2_{Y}-(2{\mathbb {M}}_c)^2}$$ to determine the optimal energy scales of the QCD spectral densities, moreover, we take the experimental values of the masses of the Y(4260 / 4220), Y(4360 / 4320), Y(4390) and Y(4660 / 4630) as input parameters and fit the pole residues to reproduce the correlation functions at the QCD side. The numerical results support assigning the Y(4660 / 4630) to be the $$C \otimes \gamma _\mu C$$ type vector tetraquark state $$c\bar{c}s\bar{s}$$, assigning the Y(4360 / 4320) to be $$C\gamma _5 \otimes \gamma _5\gamma _\mu C$$ type vector tetraquark state $$c\bar{c}q\bar{q}$$, and disfavor assigning the Y(4260 / 4220) and Y(4390) to be the pure vector tetraquark states.

This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1140%2Fepjc%2Fs10052-018-5996-5.pdf

Zhi-Gang Wang. Vector tetraquark state candidates: Y(4260 / 4220), Y(4360 / 4320), Y(4390) and Y(4660 / 4630), The European Physical Journal C, 2018, 518, DOI: 10.1140/epjc/s10052-018-5996-5