Cross section measurement and spin-parity analysis of the reaction γγ → ωϱ

• Published in: Physics letters. B 1991-03, Vol.257 (3), p.505-513
• Main Authors: Behrend, H.-J., Criegee, L., Field, J.H., Franke, G., Jung, H., Meyer, J., Podobrin, O., Schröder, V., Winter, G.G., Bussey, P.J., Campbell, A.J., Hendry, D., Lumsdon, S., Skillicorn, I.O., Ahme, J., Blobel, V., Feindt, M., Fenner, H., Harjes, J., Köhne, J.H., Peters, J.H., Spitzer, H., Weihrich, T., Apel, W.-D., Engler, J., Flügge, G., Fries, D.C., Fuster, J., Gamerdinger, K., Grosse-Weismann, P., Küster, H., Müller, H., Ranitzsch, K.H., Schneider, H., de Boer, W., Buschhorn, G., Grindhammer, G., Gunderson, B., Kiesling, Ch, Kotthaus, R., Kroha, H., Lüers, D., Oberlack, H., Schacht, P., Scholz, S., Wiedenmann, W., Davier, M., Grivaz, J.F., Haissinski, J., Journé, V., Le Diberder, F., Veillet, J.-J., Blohm, K., George, R., Goldberg, M., Hamon, O., Kapusta, F., Poggioli, L., Rivoal, M., d'Agostini, G., Ferrarotto, F., Iacovacci, M., Shooshtari, G., Stella, B., Cozzika, G., Ducros, Y., Alexander, G., Beck, A., Bella, G., Grunhaus, J., Klatchko, A., Levy, A., Milsténe, C.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(91)91928-O

We present results of an analysis of the reaction γγ→ ωϱ in the two-photon process e +e −→ ϵ +e −2 π +2 π − π 0 in the untagged mode. The cross section is largely compatible with previous determinations; however, we do not confirm the enhancement claimed at 1.9 GeV. All observed ω's are accompanied by ϱ's in the recoiling ππ spectrum. An angular correlation analysis shows that the data is not dominated by a single spin-parity state, thus establishing severe constraints on qq q q models which predict J P = 2 + .