2019 Impact factor 4.389
Particles and Fields
Eur. Phys. J. C 8, 59-66
DOI 10.1007/s100529901103

First observation of \ensuremath{\mathrm{\Sigma^-}}-\ensuremath{\mathrm{e^-}} elastic scattering in the hyperon beam experiment WA89 at CERN

The WA89 Collaboration

M.I. Adamovich 8 - Yu.A. Alexandrov 8 - D. Barberis 3 - M. Beck 5 - C. Bérat 4 - W. Beusch 2 - M. Boss 6 - S. Brons 5 - W. Brückner 5 - M. Buénerd 4 - C. Busch 6 - C. Büscher 5 - F. Charignon 4 - J. Chauvin 4 - E.A. Chudakov 6 - U. Dersch 5 - F. Dropmann 5 - J. Engelfried 6 - F. Faller 6 - A. Fournier 4 - S.G. Gerassimov 5,8 - M. Godbersen 5 - P. Grafström 2 - Th. Haller 5 - M. Heidrich 5 - E. Hubbard 5 - R.B. Hurst 3 - K. Königsmann 5 - I. Konorov 5,8 - N. Keller 6 - K. Martens 6 - Ph. Martin 4 - S. Masciocchi 5 - R. Michaels 5 - U. Müller 7 - H. Neeb 5 - D. Newbold 1 - C. Newsom - S. Paul 5 - J. Pochodzalla 5 - I. Potashnikova 5 - B. Povh 5 - R.D. Ransome - Z. Ren 5 - M. Rey-Campagnolle 4 - G. Rosner 7 - L. Rossi 3 - H. Rudolph 7 - C. Scheel - L. Schmitt 7 - H.-W. Siebert 6 - A. Simon 6 - V.J. Smith 1 - O. Thilmann 6 - A. Trombini 5 - E. Vesin 4 - B. Volkemer 7 - K. Vorwalter 5 - Th. Walcher 7 - G. Wälder 6 - R. Werding 5 - E. Wittmann 5 - M.V. Zavertyaev 8

1 University of Bristol, Bristol, UK
2 CERN, CH-1211 Genève 23, Switzerland
3 Genoa University/INFN, Dipartimento di Fisica, I-16146 Genova, Italy
4 Grenoble ISN, F-38026 Grenoble, France
5 Heidelberg Max-Planck-Institut für Kernphysik, Postfach 103980, D-69029 Heidelberg, Germany
6 Universität Heidelberg, Physikal. Institut, D-69120 Heidelberg Germany
7 Universität Mainz, Institut für Kernphysik, D-55099 Mainz, Germany
8 Moscow Lebedev Physics Institute, 117924 Moscow, Russia

Received: 23 October 1998 / Published online: 1 March 1999

Abstract
We have investigated the elastic scattering of high energy $\Sigma^-$off electrons from carbon and copper targets using the CERN hyperon beam. Scattering events are identified using a maximum likelihood technique exploring the kinematical relations of the scattered particles. The observed Q2-distribution of these events suggests a mean square charge radius of the $\Sigma^-$ of $<r^{2}_{ch}\gt(\Sigma^-) = 0.91 \pm 0.32 (stat.) \pm 0.4$ (syst.) fm2. This constitutes the first measurement of $<r^{2}_{ch}\gt(\Sigma^-)$ and demonstrates the possibility to also measure the charge radii of other hyperons.


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