TEST OF CHIRAL PERTURBATION-THEORY IN ETA-DECAYS

Authors
AMSLER C ARMSTRONG DS AUGUSTIN I BAKER CA BARNETT BM BATTY CJ BEUCHERT K BIRIEN P BISTIRLICH J BLUM P BOSSINGHAM R BOSSY H BRAUNE K BROSE J BUGG DV BURCHELL M CASE T COOPER A CROWE KM DIETZ HP DOMBROWSKI SV DOSER M DUNNWEBER W ENGELHARDT D ENGLERT M FAESSLER M FELIX C FOLGER G HACKMAN R HADDOCK RP HEINSIUS FH HESSEY NP HIDAS P ILLINGER P JAMNIK D JAVORFI Z KALINOWSKI H KAMMLE B KIEL T KISIEL J KLEMPT E KOBEL M KOCH H KOLO C KONIGSMANN K KUNZE M LANDUA R LUDEMANN J MATTHAY H MERKEL M MERLO JP MEYER CA MONTANET L NOBLE A OULDSAADA F PETERS K PINTER G RAVNDAL S SALK J SANJARI A SCHAFER E SCHMID B SCHMIDT P STRASSBURGER C STROHBUSCH U SUFFERT M UMER D VOLCKER C WALTER F WALTHER D WASSMER S WIEDNER U ZOLL J ZUPANCIC C
Citation
C. Amsler et al., TEST OF CHIRAL PERTURBATION-THEORY IN ETA-DECAYS, Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields, 107(11), 1994, pp. 2589-2594
Citations number
9
Categorie Soggetti
Physics, Particles & Fields
Journal title
Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields → ACNP
ISSN journal
11241861
Volume
107
Issue
11
Year of publication
1994
Pages
2589 - 2594
Database
ISI
SICI code
1124-1861(1994)107:11<2589:TOCPIE>2.0.ZU;2-I
Abstract
The decay of the vl-meson into three pions plays an important role as a test of low-energy QCD calculations in the framework of chiral pertu rbation theory. Previous experiments show results that are inconclusiv e or even contradictory. The Crystal Barrel experiment at LEAR has det ermined the braching ratios Gamma(eta-->-3 pi(0))/Gamma(eta-->eta(+)et a(-)eta(0)) = 1.47 +/- 0.09 +/- 0.15 and Gamma(eta-->gamma gamma)/Gamm a(eta-->pi(+)pi(-)pi-(0)) = = 1.88 +/- 0.10 +/- 0.17 using its unique features to detect charged particles as well as neutral particles. The value for the first ratio agrees nicely with the theoretical predicti ons and solves previous experimantal uncertainties. The second value, which yields a partial width of Gamma(eta-->pi n(+)pi(-)pi(0)) = (0.24 +/- 0.03) keV, shows that the same next-to-leading order chiral pertu rbation theory calculations still have some problems.