Rare Decays of the {eta} Meson

Journal Article · Sat Feb 11 00:00:00 EST 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2176523· OSTI ID:20798113

Papandreou, Zisis ^[1]

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1. Department of Physics, University of Regina, Regina, SK, S4S 0A2 (Canada)

A study of several rare {eta} decays near threshold was carried out at the C-6 ({pi}-) beamline of the Alternating Gradient Synchrotron at Brookhaven National Laboratory with the Crystal Ball detector, an electromagnetic calorimeter with nearly 4{pi} geometric acceptance that is comprised of 672 optically isolated NaI(Tl) crystals with a thickness of 15.7 radiation lengths.Results from the search for the CP forbidden decay {eta} {yields} 4{pi}0 and the investigation of the quadratic slope parameter in {eta} {yields} 3{pi}0 decay will be profiled, among others. The focus of the talk will be on the {eta} {yields} {pi}0{gamma}{gamma} rare decay: its relative branching ratio was extracted to be B1 = (8.3 {+-} 2.8 {+-} 1.2) x 10-4, based on the analysis of 3 x 107 detected {eta} mesons. This leads to a partial width for the eta meson of {gamma}({eta} {yields} {pi}0{gamma}{gamma}) = (0.32 {+-} 0.15) eV/c2, a value much lower than past measurements and in line with Chiral Perturbation Theory calculations.

• OSTI ID: 20798113
• Journal Information: AIP Conference Proceedings, Vol. 814, Issue 1; Conference: 11. international conference on hadron spectroscopy, Rio de Janeiro (Brazil), 21-26 Aug 2005; Other Information: DOI: 10.1063/1.2176523; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BRANCHING RATIO
CHIRALITY
CP INVARIANCE
CRYSTALS
ETA MESONS
EV RANGE
MULTIPARTICLE SPECTROMETERS
PARTICLE DECAY
PARTICLE IDENTIFICATION
PARTICLE PRODUCTION
PARTICLE WIDTHS
PERTURBATION THEORY
PHOTON-MESON INTERACTIONS
PHOTONS
PIONS NEUTRAL
RADIATION LENGTH
SHOWER COUNTERS