Central exclusive production of axial-vector $f_1$ mesons in proton-proton collisions

The production of $f_1$ ($J^{PC}=1^{++}$) mesons in proton-proton collisions via pomeron-pomeron fusion is discussed. Two ways to construct the pomeron-pomeron-$f_1$ coupling are presented. Comparisons with data from the WA102 experiment are made and predictions for RHIC and LHC experiments are given.