Further signatures to support the tetraquark mixing framework for the two light-meson nonets

Kim, H.*; Kim, K. S.*; Cheoun, M.-K.*; Jido, Daisuke*; Oka, Makoto

Physical Review D, 99(1), p.014005_1 - 014005_15, 2019/01

https://doi.org/10.1103/PhysRevD.99.014005

We investigate additional signatures to support the tetraquark mixing framework that has been recently proposed as a possible structure for the two nonets. We reexamine the mass ordering generated from the tetraquark nonets and show that this mass ordering is satisfied by the two nonets although the ordering in the heavy nonet is marginal. The marginal mass ordering can be regarded as another signature for tetraquarks because it can be explained partially by the hyperfine masses calculated from the tetraquark mixing framework. As a peculiar signature distinguished from the other approaches, we investigate the fall-apart coupling strengths into two vector mesons from our tetraquarks. Coupling strengths into the two-vector modes are found to enhance strongly in the heavy nonet while they are suppressed in the light nonet. The coupling ratios are found to be huge. This trend in the two-vector modes can provide another testing ground for the tetraquark mixing framework. Some experimental evidence related to the phenomena is discussed particularly from the resonances belonging to the heavy nonet.