Masses, decays and mixings of gluonia in QCD

Dec, 1996
32 pages
Published in:
  • Nucl.Phys.B 509 (1998) 312-356
e-Print:
Report number:
  • PM-96-37

Citations per year

199720042011201820240510152025
Abstract: (Elsevier)
We compute the masses and decay widths of the gluonia using QCD spectral sum rules and low-energy theorems. In the scalar sector, one finds a gluonium having a mass M G = (1.5 ± 0.2) GeV, which decays mainly into the U (1) A channels ηη′ and 4π 0 . However, for a consistency of the whole approach, one needs broad low-mass gluonia (the σ B and its radial excitation), which couple strongly to the quark degrees of freedom similarly to the η′ of the U (1) A sector. Combining these results with the ones for the q¯q quarkonia, we present maximal gluonium-quarkonium mixing schemes, which can provide quite a good description of the complex spectra and various decay widths of the observed scalar mesons σ(1.), f 0 (0.98), f 0 (1.37), f 0 (1.5) and f J (1.71). In the tensor sector, the gluonium mass is found to be M T ⋍ (2.0±0.1) GeV, which makes the ζ(2.2) a good 2 ++ gluonium candidate, even though we expect a rich population of 2 ++ gluonia in this region. In the pseudoscalar channel, the gluonium mass is found to be M p ⋍ (2.05 ± 0.19) GeV, while we also show that the E /ι(1.44) couples more weakly to the gluonic current than the η′(0.96), which can favour its interpretation as the first radial excitation of the η′(0.96).
  • 12.40.Yx
  • glueball: mass
  • glueball: width
  • glueball: decay modes
  • glueball: quantum number
  • quantum chromodynamics: sum rule
  • spectral representation
  • low-energy theorem
  • quarkonium: scalar
  • scalar meson: width