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Title: Rare Decays of the {eta} Meson

Abstract

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.

Authors:
 [1]
  1. Department of Physics, University of Regina, Regina, SK, S4S 0A2 (Canada)
Publication Date:
OSTI Identifier:
20798113
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 814; Journal 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)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Papandreou, Zisis. Rare Decays of the {eta} Meson. United States: N. p., 2006. Web. doi:10.1063/1.2176523.
Papandreou, Zisis. Rare Decays of the {eta} Meson. United States. doi:10.1063/1.2176523.
Papandreou, Zisis. Sat . "Rare Decays of the {eta} Meson". United States. doi:10.1063/1.2176523.
@article{osti_20798113,
title = {Rare Decays of the {eta} Meson},
author = {Papandreou, Zisis},
abstractNote = {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.},
doi = {10.1063/1.2176523},
journal = {AIP Conference Proceedings},
number = 1,
volume = 814,
place = {United States},
year = {Sat Feb 11 00:00:00 EST 2006},
month = {Sat Feb 11 00:00:00 EST 2006}
}