Proposal to study 50,000 Sigman- n multiprong events at 240-GeV/c by means of the 15 foot bubble chamber

In contrast to the large amount of data accumulated in non strange baryon-baryon interactions, there is only a limited amount of information available on {Sigma}N interactions. As a {Sigma}{sup -}p experiment at 240 GeV/c has already been approved with the 15', we propose to complete this experiment by studying the {Sigma}{sup -}n interactions at the same incident momentum. This will allow us to make a comparison between {Sigma}{sup -}n and {Sigma}{sup -}p reactions and to detect thus the isospin influence on the {Sigma}N interactions. Furthermore, as previous bubble chamber experiments at FNAL have shown that four constraint reactions can be studied, the use of a neutron target will give us access to four constraint final states which cannot be obtained from the {Sigma}{sup -}p experiment. The utilization of a deuteron target will of course complicate somewhat the data analysis. Nevertheless this is a convenient method to study the pure 1=3/2 EN isospin state as {Sigma}{sup +}p experiments are more difficult to carry out than {Sigma}{sup -}n. In a first step we would like to have a statistics corresponding to 50,000 multiprong events, i.e., events having more than two prongs.