Singlet-octet-glueball mixing of scalar mesons

Abstract

The mixing angles between scalar isoscalar resonances and a scalar glueball are determined from their decays into two pseudoscalar mesons. For f 0 (1370) and f 0 (1500), at most a small glueball component is admitted by the data. The decay modes of f 0 (1710), f 0 (1770), f 0 (2020), and f 0 (2100) require significant glueball fractions. Above this mass, the errors in the decay frequencies become too large to extract a glueball component. The summation of all observed glueball fractions up to 2100 MeV yields (78±18)%. The glueball fractions as function of the mass are consistent with a scalar glueball at 1965 MeV and a width of 370 MeV as suggested by a measurement of the yield of scalar isoscalar mesons in radiative J/ψ decays.

An updated review of the new hadron states

“…The above mixing scheme seems necessary to understand the scalar glueball. In a recent study [871] the authors studied the mixing between the scalar glueball and six scalar mesons from their decays into two pseudoscalar mesons. These six mesons are the f 0 (1370), f 0 (1500), f 0 (1710), f 0 (1770), f 0 (2020), and f 0 (2100), whose parameters have been listed in Table 14.…”

“…Using the experimental decay data as inputs, the authors of Ref. [871] determined the six quarkonia-glueball mixing angles, and extracted the fractional glueball contents of these resonances to be:…”

“…Recently, the authors of Refs. [829,871] proposed the existence of a distributed scalar glueball, with the mass around 1865 MeV and width around 370 MeV [871], which widely mixes with the scalar mesons f 0 (1370), f 0 (1500), f 0 (1710), f 0 (1770), f 0 (2020), and f 0 (2100), etc. Although these theoretical studies bring us a new viewpoint, the broad width and the mixing effect of this distributed glueball may hinder its experimental observation easily.…”

Scalar and tensor resonances in $$J/\psi $$ radiative decays

“…The idea of characterizing the glueball properties through the couplings of all the scalar mesons to radiative J/ψ decays was considered in [59,60], and in [61] its singlet and octect mixing angles were studied. The isoscalar-tensor sector appears to be better understood.…”

Quenched glueballs in the DSE/BSE framework

“…Prominent candidates for scalar and tensor glueballs are the measured f 0 and f 2 states. Their gluonic content as determined from radiative J/ψ decays was discussed recently in [6][7][8]. On the theory side, the benchmark has been lattice simulations of the glueball spectrum [9][10][11][12].…”