Observation of an Isoscalar Resonance with Exotic J^PC=1^(-+) Quantum Numbers in J/ψ→γηη'
The BESIII collaboration reported the observation of an isoscalar resonance with exotic JPC=1-+ quantum numbers. This research is published in Physical Review Letters [Phys. Rev. Lett. 129, 192002 (2022)], accompanied by a detailed companion paper in Physical Review D [Phys. Rev. D 106, 072012 (2022)]. This is an observation of a new category of hadronic matter, which is an important step forward in low energy QCD.