Test of chiral perturbation theory in η decays

Autor: R. Bossingham, C. A. Meyer, J. Lüdemann, R. P. Haddock, A. Noble, A. Cooper, M. A. Faessler, A. H. Sanjari, T. Case, B. Schmid, H. Matthäy, G. Pinter, K. Braune, J. Zoll, C. Felix, B. M. Barnett, P. Schmidt, D. Walther, Eberhard Klempt, G. Folger, L. Montanet, W. Dünnweber, James A. Bistirlich, H. P. Dietz, Michael Kobel, Pàl Hidas, C.A. Baker, D. Umer, Claude Amsler, M. Suffert, I. Augustin, F. Walter, R. Hackmann, S. v. Dombrowski, D. S. Armstrong, P. Birien, Kenneth M. Crowe, M. Merkel, H. Kalinowski, Č. Zupančič, Z. Jávorfi, B. Kämmle, K. Beuchert, C. Kolo, F. Ould-Saada, C. Straßburger, D. Jamnik, P. Illinger, N. P. Hessey, D. Engelhardt, J. Brose, F. H. Heinsius, C. Völcker, U. Wiedner, Michael Doser, Mark J. Burchell, J. P. Merlo, M. Englert, Marcel Kunze, K. Königsmann, T. Kiel, J. Kisiel, H. Bossy, S. Ravndal, P. Blüm, D.V. Bugg, J. Salk, S. Waßmer, C.J. Batty, H. Koch, U. Strohbusch, R. Landua, E. Schäfer, Krisztian Peters
Rok vydání: 1994
Předmět:
Zdroj: Il Nuovo Cimento A. 107:2589-2594
ISSN: 1826-9869
0369-3546
DOI: 10.1007/bf02734034
Popis: The decay of the η-meson into three pions plays an important role as a test of low-energy QCD calculations in the framework of chiral perturbation theory. Previous experiments show results that are inconclusive or even contradictory. The Crystal Barrel experiment at LEAR has determined the braching ratiosΓ(η→3π0)/Γ(η→π+π−π0)=1.47±0.09±0.15 andΓ(η→γγ)/Γ(η→π+π−π0)=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 predictions and solves previous experimental uncertainties. The second value, which yields a partial width ofΓ(η→π+π−π0)=(0.24±0.03) keV, shows that the same next-to-leading order chiral perturbation theory calculations still have some problems.
Databáze: OpenAIRE