Higher quarkonia

Abstract

In this paper we survey all radial and orbital excitations of the Iϭ0 and Iϭ1 nn system anticipated up to 2.1 GeV. We give detailed predictions of their quasi-two-body branching fractions and identify characteristic decay modes that can isolate quarkonia; this should be useful in distinguishing quarkonia from glueballs and hybrids. Several of the ''missing mesons'' with L q q ϭ2 and L q q ϭ3 are predicted to decay dominantly into certain Sϩ P and SϩD modes, and should appear in experimental searches for hybrids in the same mass region. We also consider the topical issues of whether some of the recently discovered or controversial meson resonances, including glueball and hybrid candidates, can be accommodated as quarkonia.

Radiative decays: A new flavor filter

“…The E852 experiment at Brookhaven has observed [27] the decay ω(1640) → ωη. If the ω(1640) ≡ ω D then, in the 3 P 0 model, the partial width for this mode is predicted [9] to be 13 MeV. Thus, if the 3 P 0 model is a good guide in this case, a measureable ω(1640) → γa 1 is anticipated: as E852 have several thousand events in the ωη channel, it is possible that there could be several hundred γa 1 events in their experiment.…”

“…The natural inference is that there is a glueball state present [4,5]. A clear exotic resonance, π 1 (1600), with quantum numbers J P C = 1 −+ which cannot be accessed by a pure quark-antiquark state, has been seen [6] in the η ′ (958)π channel in the reaction π − N → (η ′ (958)π)N and in the ρ 0 π − channel [7,8] in the reaction π − N → (π + π − π − )N. Anomalously large hadronic decay modes of light-quark vector mesons, that is decays which are predicted to be very small in standard models [9], are observed in e + e − annihilation around 1.6 GeV. A favoured explanation [10,11,12] is to include vector hybrids which, on the basis of the π 1 (1600) mass, are expected to be in this mass region.…”

Sketching the Bethe-Salpeter Kernel

“…In this spectrum the π(1300) is a radial excitation of the π(140) [1,2], the π(1800) is possibly a hybrid [3], and the dressed-quarks within scalar-and pseudovectormesons possess significant orbital angular momentum [4,5,6]. Hence, relative to ground-state pseudoscalar and vector mesons, these states are sensitive to different features of the interaction between light-quarks and to that interaction at larger distances [1,2,5,6].…”

“…For ω ∈ [0.3, 0.5] GeV, using Eq. (14), ground-state pseudoscalar and vector-meson observables are roughly constant if ωD = (0.8 GeV) 3 .…”

D and D s in mass loaded flux tube

“…In most quark models, the interactions between the quark and the antiquark include the spinindependent confinement interaction, the spin-dependent interactions (spin-orbit interaction, color hyperfine interaction) and some other interactions [1,21,22,23]. The spin-orbit interaction consists of a color-magnetic piece and a Thomas-precession piece.…”