Lightest scalar and tensor resonances in {gamma}{gamma}{yields}{pi}{pi} after the Belle experiment

Journal Article · Tue Apr 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.074020· OSTI ID:21249945

Achasov, N N; Shestakov, G N ^[1]

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1. Laboratory of Theoretical Physics, S.L. Sobolev Institute for Mathematics, 630090, Novosibirsk (Russian Federation)

New high statistics Belle data on the {gamma}{gamma}{yields}{pi}{sup +}{pi}{sup -} reaction cross section measured in the range of pion-pair invariant masses {radical}(s) between 0.8 GeV and 1.5 GeV are analyzed to clarify the current situation around the {sigma}(600), f{sub 0}(980), and f{sub 2}(1270) resonances in {gamma}{gamma} collisions. The present analysis shows that the direct coupling constants of the {sigma}(600) and f{sub 0}(980) resonances to {gamma}{gamma} are small, and the {sigma}(600){yields}{gamma}{gamma} and f{sub 0}(980){yields}{gamma}{gamma} decays are four-quark transitions caused by the {pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} loop mechanisms, respectively. The chiral shielding of the {sigma}(600) resonance takes place in the reactions {gamma}{gamma}{yields}{pi}{pi} as well as in {pi}{pi} scattering. Some results of a simultaneous description of the {gamma}{gamma}{yields}{pi}{sup +}{pi}{sup -} and {gamma}{gamma}{yields}{pi}{sup 0}{pi}{sup 0} Belle data are also presented. In particular, the following tentative estimate of the f{sub 2}(1270){yields}{gamma}{gamma} decay width is obtained: {gamma}{sub f{sub 2}}{sub {r_reversible}}{sub {gamma}}{sub {gamma}}(m{sub f{sub 2}}{sup 2}){approx_equal}3.68 keV.

• OSTI ID: 21249945
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRALITY
COLLISIONS
COUPLING CONSTANTS
CROSS SECTIONS
F0-980 MESONS
F2-1270 MESONS
GAMMA RADIATION
GEV RANGE 01-10
KAONS MINUS
KAONS PLUS
KEV RANGE 01-10
MASS
PARTICLE DECAY
PHOTON-PHOTON INTERACTIONS
PION-PION INTERACTIONS
PIONS MINUS
PIONS PLUS
QUARKS
RESONANCE
SHIELDING