The scalar and tensor glueball in production and decay

Abstract

Evidence for the scalar and the tensor glueball is reported. The evidence stems from an analysis of BESIII data on radiative J/\psiJ/ψ data into \pi^0\pi^0π0π0, K_SK_SKSKS, \eta\etaηη, and \phi\omegaϕω [1]. The coupled-channel analysis is contrained by a large number of further data. The scalar intensity is described by ten scalar isoscalar mesons, covering the range from f_0(500)f0(500) to f_0(2330)f0(2330). Five resonances are interpreted as mainly-singlet states in SU(3), five as mainly-octet states. The mainly-singlet resonances are produced over the full mass range, the production of octet states is limited to the 1500 to 2100,MeV mass range and shows a large peak. The peak is interpreted as scalar glueball. Its mass, width and yield are determined to M_{glueball}=(1865\pm 25)Mglueball=(1865±25),MeV, \Gamma_{glueball} = (370\pm 50^{+30}_{-20})\,MeVΓglueball=(370±50−20+30)MeV, Y_{J/\psi\to \gamma G_0}=(5.8\pm1.0)\cdot 10^{-3}YJ/ψ→γG0=(5.8±1.0)⋅10−3. The study of the decays of the scalar mesons identifies significant glueball fractions [2]. The tensor wave shows the f_2(1270)f2(1270) and f_2'(1525)f2′(1525) and a small enhancement at M=2210\pm40M=2210±40 MeV, \Gamma= (355^{+60}_{-30})\,MeVΓ=(355−30+60)MeV [3]. An interpretation of these data is suggested.