1. Observation of a resonance in the K$_s$p decay channel at a mass of 1765 MeV/c$^2$
- Author
-
WA89 Collaboration, Adamovich, M. I., Alexandrov, Yu. A., Barberis, D., Beck, M., Bérat, C., Beusch, W., Boss, M., Brons, S., Brückner, W., Buénerd, M., Busch, C., Büscher, C., Charignon, F., Chauvin, J., Chudakov, E. A., Dersch, U., Dropmann, F., Engelfried, J., Faller, F., Fournier, A., Gerassimov, S. G., Godbersen, M., Grafström, P., Haller, Th., Heidrich, M., Hubbard, E., Hurst, R. B., Königsmann, K., Konorov, I., Keller, N., Martens, K., Martin, Ph., Masciocchi, S., Michaels, R., Müller, U., Neeb, H., Newbold, D., Newsom, C., Paul, S., Pochodzalla, J., Potashnikova, I., Povh, B., Ren, Z., Rey-Campagnolle, M., Rosner, G., Rossi, L., Rudolph, H., Scheel, C., Schmitt, L., Siebert, H. -W., Simon, A., Smith, V., Thilmann, O., Trombini, A., Vesin, E., Volkemer, B., Vorwalter, K., Walcher, Th., Wälder, G., Werding, R., Wittmann, E., and Zavertyaev, M. V.
- Subjects
High Energy Physics - Experiment - Abstract
We report on the observation of a K$_s$p resonance signal at a mass of 1765$\pm$5 MeV/c$^2$, with intrinsic width $\Gamma = 108\pm 22$ MeV/c$^2$, produced inclusively in $\Sigma^-$-nucleus interactions at 340 GeV/c in the hyperon beam experiment WA89 at CERN. The signal was observed in the kinematic region $x_F>0.7$, in this region its production cross section rises approximately linearly with $(1-x_F)$, reaching $BR(X\to K_S p)\cdot d\sigma /dx_F = (5.2\pm 2.3) \mu b $ per nucleon at $x_F=0.8$. The hard \xf spectrum suggests the presence of a strong leading particle effect in the production and hence the identification as a $\Sigma^{*+}$ state. No corresponding peaks were observed in the $K^- p$ and $\Lambda \pi^{\pm}$ mass spectra.
- Published
- 2007
- Full Text
- View/download PDF