ISSN:
1432-5411
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Ground-state masses ofq 2 $$\bar q$$ −2 states (“true” and “mock” baryonium) are investigated in the framework of a Bethe-Salpeter formalism motivated from QCD. The four-particle system is described by pairwise interactions betweenqq orq $$\bar q$$ pairs with a spectator approximation for the non-interacting pair. The quark-quark interactions are Coulomb plus harmonic interactions; the harmonic terms have been modified to produce linear confinement for heavier quarks, in agreement with experimental spectra. The confining interaction is proportional to the strong coupling constantα s. Apart from the quark masses, the confining interaction is characterized by three basic parameters: (i) a universal spring constantω 0; (ii) a constantC 0/ω 0 2 , which defines the vacuum structure; (iii) a constantA 0, which provides a smooth transition from quadratic to linear confinement as one goes from light to heavy quark systems. These three constants [ω 0 = 0.158 GeV;C 0=0.296;A 0=0.0283] have been shown to produce excellent fits to all quarkonia states [q $$\bar q$$ ,q $$\bar Q$$ ,Q $$\bar Q$$ ] as well as baryon spectra (qqq); thus our predictions forq 2 $$\bar q$$ 2 states contain no free parameters. In this model, theL=0 ground states occur in the range 1.8–2 GeV, 2.15–2.3 GeV and 6.72–6.75 GeV foru 2 ū 2,s 2 $$\bar s$$ 2 andc 2 $$\bar c$$ 2 states, respectively. We discuss the prospects for these states to be seen experimentally. In the case of thes 2 $$\bar s$$ 2 state, this is likely to have a rather narrow width, and may correspond to theX(2.22 GeV) meson observed in radiative decays of theJ/ψ meson. Thec 2 $$\bar c$$ 2 state might also be visible as a ψψ resonance with an appreciable width.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01078974
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