Charmonium: Comparison with experiment

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.21.203· OSTI ID:5729035

Eichten, E; Gottfried, K; Kinoshita, T; Lane, K D; Yan, T M

The charmonium model, formulated in detail in an earlier publication, is compared in a comprehensive fashion with the data on the psi family. The parameters of the ''naive'' model, in which the system is described as a cc-bar pair, are determined from the observed positions of psi, psi', and the P states. The model then yields a successful description of the spectrum of spin-triplet states above the charm threshold. It also accounts for the ratio of the leptonic widths of psi' and psi. When the cc-bar potential is applied to the UPSILON family, it accounts, without any readjustment of parameters, for the positions of the 2S and 3S levels and for the leptonic widths of UPSILON and UPSILON' relative to that of psi. The model does not give acceptable values of the absolute leptonic widths, a shortcoming which is ascribed to large quantum-chromodynamic corrections to the van Royen--Weisskopf formula. The calculated E1 rates are about twice the values observed in the psi family. This naive model is also extended with considerable success to mesons composed of one heavy and one light quark. A significant extension of the model is achieved by incorporating coupling to charmed-meson decay channels. This gives a satisfactory understanding of psi (3772) as the 1/sup 3/D/sub 1/ cc-bar state, mixed via open and closed decay channels to 2/sup 3/S. The model has decay amplitudes that are oscillatory functions of the decay momentum; these oscillations are a direct consequence of the radial nodes in the cc-bar parent states. These amplitudes provide a qualitative understanding of the observed peculiar branching ratios into various charmed-meson channels near the resonance at 4.03 GeV, which is assigned to 3/sup 3/S. The coupling of the cc-bar states below the charm threshold to closed decay channels modifies the bound states and leads to reduction of about 20% in E1 rates in comparison to those of the naive model.

• Research Organization: Laboratory of Nuclear Studies, Cornell University, Ithaca, New York 14853
• OSTI ID: 5729035
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 21:1; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645201* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- General & Scattering Theory
645400 -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOSONS
BOUND STATE
BRANCHING RATIO
CHARMONIUM
COULOMB FIELD
COUPLING CONSTANTS
DECAY
DIFFERENTIAL EQUATIONS
ELECTRIC FIELDS
ELEMENTARY PARTICLES
EQUATIONS
FIELD THEORIES
HADRONS
INTERACTIONS
MASS DIFFERENCE
MATHEMATICAL MODELS
MESON RESONANCES
MESONS
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PSI RESONANCES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK-ANTIQUARK INTERACTIONS
RESONANCE PARTICLES
SCHROEDINGER EQUATION
VECTOR MESONS
WAVE EQUATIONS