Structure of the scalar mesons {ital f}{sub 0}(980) and {ital a}{sub 0}(980)

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.52.2690· OSTI ID:115922

Janssen, G ^[1]; Pearce, B C ^[2]; Holinde, K; Speth, J ^[3]

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1. Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States)
2. Department of Physics and Mathematical Physics, University of Adelaide, Adelaide, S 5005 (Australia)
3. Institut fuer Kernphysik, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)

We investigate the structure of the scalar mesons {ital f}{sub 0}(980) and {ital a}{sub 0}(980) within realistic meson-exchange models of the {pi}{pi} and {pi}{eta} interactions. Starting from a modified version of the Juelich model for {pi}{pi} scattering we perform an analysis of the pole structure of the resulting scattering amplitude and find, in contrast with existing models, a somewhat large mass for the {ital f}{sub 0}(980) ({ital m}{sub {ital f}0}=1015 MeV, {Gamma}{sub {ital f}0}=30 MeV). It is shown that our model provides a description of {ital J}/{psi}{r_arrow}{phi}{pi}{pi}/{phi}{ital KK} data comparable in quality with those of alternative models. Furthermore, the formalism developed for the {pi}{pi} system is consistently extended to the {pi}{eta} interaction leading to a description of the {ital a}{sub 0}(980) as a dynamically generated threshold effect (which is therefore neither a conventional {ital q{bar q}} state nor a {ital K{bar K}} bound state). Exploring the corresponding pole position the {ital a}{sub 0}(980) is found to be rather broad ({ital m}{sub {ital a}0}=991 MeV, {Gamma}{sub {ital a}0}=202 MeV). The experimentally observed smaller width results from the influence of the nearby {ital K{bar K}} threshold on this pole.

• OSTI ID: 115922
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 5 Vol. 52; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
A0-980 MESONS
ETA MESONS
J PSI-3097 MESONS
PARTICLE STRUCTURE
PION-PION INTERACTIONS
SCALAR FIELDS
SCATTERING AMPLITUDES