Observation of a new eta pi0 pi0 resonance at 1900 MeV/c^2 in two-photon scattering

Articolo

Data di Pubblicazione:

1990

Citazione:

Observation of a new eta pi0 pi0 resonance at 1900 MeV/c^2 in two-photon scattering / K., Karch; D., Antreasyan; H. W., Bartels; D., Besset; Bieler, C. H.; J. K., Bienlein; Bizzeti, Andrea; E. D., Bloom; I., Brock; K., Brockmüller; R., Cabenda; A., Cartacci; M., Cavalli Sforza; R., Clare; A., Compagnucci; G., Conforto; S., Cooper; R., Cowan; D., Coyne; A., Engler; K., Fairfield; G., Folger; A., Fridman; J., Gaiser; D., Gelphman; G., Glaser; G., Godfrey; K., Graaf; F. H., Heimlich; F. H., Heinsius; R., Hofstadter; J., Irion; Z., Jakubowski; H., Janssen; S., Keh; T., Kiel; H., Kilian; I., Kirkbride; T., Kloiber; M., Kobel; W., Koch; A. C., König; K., Königsmann; R. W., Kraemer; S., Krüger; G., Landi; R., Lee; S., Leffler; R., Lekebusch; A. M., Litke; W., Lockman; S., Lowe; B., Lurz; D., Marlow; H., Marsiske; W., Maschmann; P., Mcbride; F., Messing; W. J., Metzger; H., Meyer; B., Monteleoni; B., Muryn; R., Nernst; B., Niczyporuk; G., Nowak; C., Peck; P. G., Pelfer; B., Pollock; F. C., Porter; D., Prindle; P., Ratoff; M., Reidenbach; B., Renger; C., Rippich; M., Scheer; P., Schmitt; J., Schotanus; J., Schütte; A., Schwarz; D., Sievers; T., Skwarnicki; V., Stock; K., Strauch; U., Strohbusch; J., Tompkins; H. J., Trost; B., Van Uitert; R. T., Van De Walle; H., Vogel; A., Voigt; U., Volland; K., Wachs; K., Wacker; W., Walk; H., Wegener; D. A., Williams; P., Zschorsch. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - STAMPA. - 249:(1990), pp. 353-358. [10.1016/0370-2693(90)91268-G]

Abstract:

Using the Crystal Ball detector at the DORIS II e+e- storage ring, we measure the ηπ 0π 0 mass spectrum in the reaction e+e- -> e+e- eta pi0 pi0 -> e+e- 6gamma from the eta pi0 pi0 threshold to about 2500 MeV/c 2. The spectrum is dominated by the eta′, for which we determine Gamma(gamma gamma)(eta') BR(eta' -> 6 gamma)=0. 36+-0.02+-0.03 keV. In addition, we observe an enhancement in the cross section near 1900 MeV/c 2 which we attribute to the two-photon production of a new resonance X(1900). The angular distributions and the invariant mass distribution of the eta pi0 subsystem are consistent with those expected for the hypothetical eta2 meson with J(PC)=2(-+). For this J(P) assignment the resonance parameters are M(X)=1876+-35+-50 MeV/c 2, Gamma-tot(X)=228+-90+-34 MeV/c 2 and Gamma(gamma gamma)(X) BR(X -> eta pi pi)=0.9+-0.2+-0.3 keV.

Tipologia CRIS:

Articolo su rivista

Keywords:

meson resonance; gamma-gamma reaction; Crystal Ball

Elenco autori: