We model the observed J(++) mesonic mass spectrum in terms of energies for tightly knotted and linked chromoelectric QCD flux tubes. The data is fit with one- and two-parameter models. We predict a possible new state at approximately 1190 MeV and a plethora of new states above 1690 MeV.
Buniy, Roman V., Jason Cantarella, Thomas W. Kephart, and Eric J. Rawdon. "Tight knot spectrum in QCD." Physical Review D 89.5 (2014): 054513. doi: 10.1103/PhysRevD.89.054513
American Physical Society