$Z_c$ and $Z_{cs}$ systems with operator mixing at NLO in QCD sum rules

Ren-Hua Wua, Chen-Yu Wang, Ce Meng +2

We study the mass spectra of hidden-charm tetraquark systems with quantum numbers $(I^G)J^P=(1^{+})1^{+}$ using QCD sum rules. The analysis incorporates the complete next-to-leading or…