Probing Axial-Vector Charmonia chi_(c1)(1P) and chi_(c1)(2P)

We investigate the ground-state heavy quarkonium $\chi_{c1}(1P)$ and its first excited state $\chi_{c1}(2P)$ with quantum numbers $J^{PC}=1^{++}$. The masses and decay constants of these charmonium states are computed using two-point QCD sum rule method by including quark, gluon and mixed condensates up to dimension-8. We compare our numerical results with the available experimental data as well as existing theoretical predictions in the literature.