Published December 1991 | Version v1
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Resonance formation in γγ-collisions - as observed with the Crystal Ball detector

Creators

Description

Analysis of two-photon reactions with the Crystal Ball detector at the DORIS-II e+e- storage ring (Ebeam = 5 GeV) resulted in a complete set of data on γγ-formation of mesons. The data are best represented by their helicity matrix elements. For isoscalar mesons the mixing of non-strange and strange quark constituents can be derived. A highly efficient selection of the channel γγ → π0π0 yielded 7000 events with (M(π0π0) > 800 MeV/c2. A partial wave decomposition became possible and showed under the f2(1270) a scalar meson resonance f0(1250) with 4.0 standard deviations. In the same analysis 23 events of γγ → ηη have been found. (orig.)

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Additional details

Publishing Information

Imprint Title
Results on light quark spectroscopy
Imprint Pagination
27 p.
Journal Page Range
p. 2-7.
Report number
DESY--91-145

Conference

Title
4. international conference on hadron spectroscopy.
Dates
12-16 Aug 1991.
Place
College Park, MD (United States).

INIS

Country of Publication
Germany
Country of Input or Organization
Germany
INIS RN
23050595
Subject category
S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
Resource subtype / Literary indicator
Conference, Progress Report
Descriptors DEI
A0-980 MESONS; A2-1320 MESONS; BRANCHING RATIO; CONFIGURATION MIXING; D WAVES; ENERGY DEPENDENCE; ETA MESONS; ETA PRIME-958 MESONS; EXCITATION FUNCTIONS; F0-1240 MESONS; F0-975 MESONS; F2-1270 MESONS; GEV RANGE 01-10; HADRONIC PARTICLE DECAY; HELICITY; INTEGRAL CROSS SECTIONS; MATRIX ELEMENTS; MESONS; MEV RANGE 100-1000; MIXING RATIO; PAIR PRODUCTION; PARTICLE WIDTHS; PHOTON-PHOTON INTERACTIONS; PHOTOPRODUCTION; PIONS NEUTRAL; PI2-1680 MESONS; PROGRESS REPORT; RADIATIVE DECAY; REVIEWS; S WAVES; SCALAR MESONS; SPIN ORIENTATION
Descriptors DEC
BASIC INTERACTIONS; BOSONS; CROSS SECTIONS; DECAY; DOCUMENT TYPES; ELECTROMAGNETIC INTERACTIONS; ELEMENTARY PARTICLES; ENERGY RANGE; GEV RANGE; HADRONS; INTERACTIONS; MEV RANGE; ORIENTATION; PARTIAL WAVES; PARTICLE DECAY; PARTICLE INTERACTIONS; PARTICLE PRODUCTION; PARTICLE PROPERTIES; PIONS; PSEUDOSCALAR MESONS; TENSOR MESONS

Optional Information

Collaborations
Crystal Ball Collaboration.