Search for Bound States of Neutrons and Negative Pions

F. W. N. de Boer; R. van Dantzig; M. Daum; J. Jansen; P. J. S. Watson; L. Felawka; C. Grab; A. van der Schaaf; T. Kozlowski; J. Martino; A. I. Smirnov

doi:10.1103/PhysRevLett.53.423

Search for Bound States of Neutrons and Negative Pions

F. W. N. de Boer, R. van Dantzig, M. Daum, J. Jansen, P. J. S. Watson, L. Felawka, C. Grab, A. van der Schaaf, T. Kozlowski, J. Martino, and A. I. Smirnov

Phys. Rev. Lett. 53, 423 – Published 30 July 1984

Abstract

An experimental search has been performed for bound systems of neutrons and negative pions, denoted by ${(π^{-})}^{Z} n^{N}$ . Such negatively charged nuclear fragments might be emitted in energetic proton-nucleus collisions. Upper limits for production cross sections of $Z = 1$ , $N = 2 - 6$ and $Z = 2$ , $N = 3$ systems have been derived by assuming that the lifetime of the bound pion(s) is of the order of that of the free pion or longer.

Received 30 January 1984

DOI:https://doi.org/10.1103/PhysRevLett.53.423

Authors & Affiliations

F. W. N. de Boer^*

Université de Fribourg, c/o Schweizerisches Institut für Nuklearforschung, CH-5234 Villigen, Switzerland

R. van Dantzig

National Instituut voor Kernfysica en Hoge-Energiefysica, 1009 AJ Amsterdam, The Netherlands

M. Daum, J. Jansen, and P. J. S. Watson^†

Schweizerisches Institut für Nuklearforschung, CH-5234 Villigen, Switzerland

L. Felawka

Institut für Mittelenergiephysik der Eidgenössische Technische Hochschule-Zürich, CH-5234 Villigen, Switzerland

C. Grab and A. van der Schaaf

Physik-Institut der Universität Zürich, CH-8001 Zürich, Switzerland

T. Kozlowski

Institute for Nuclear Research, PL-05-400 Swierk, Otwock, Poland

J. Martino

Département de Physique and Département de Physique Nucléaire et Hautes Energies, Centre d'Etudes Nucléaires Saclay, F-91191 Gif-sur-Yvette Cédex, France

A. I. Smirnov

Leningrad Nuclear Physics Institute, 188350 Gatchina (Leningrad), U.S.S.R.

^*Present address: Gesellschaft für Schwerion-forschung, Planckstrasse 1, 6100 Darmstadt 11, West Germany.
^†Permanent address: Physics Department, Carleton University, Ottawa K1S 5BC, Canada.