### CONCERNING THE EXISTENCE OF A $Sigma$sup -$n COMPOUNDCONCERNING THE EXISTENCE OF A$Sigma$sup -$n COMPOUND

Access Restriction
Open

 Author Gandolfi, E. ♦ Heughebaert, J. ♦ Quercigh, E. Source United States Department of Energy Office of Scientific and Technical Information Content type Text Language English
 Subject Keyword PHYSICS ♦ CHARGED PARTICLES ♦ DECAY ♦ EMISSION ♦ HYPERFRAGMENTS ♦ INTERACTIONS ♦ IONIZATION ♦ KAONS ♦ KAONS-MINUS ♦ MASS ♦ NEUTRONS ♦ NUCLEAR EMULSIONS ♦ NUCLEI ♦ NUCLEONS ♦ PARTICLE MODELS ♦ PARTICLE TRACKS ♦ SIGMA PARTICLES ♦ SIGMA-MINUS ♦ STRANGENESS ♦ VARIATIONS Abstract The interactions at rest of K/sup -/-mesons with two or more nucleons were examined in a stack of K-5 emulsions each 600 mu m thick. Of 35 SIGMA tracks, two showed an anomalous variation of ionization with path length. One particle of charge 1 is shown to have a mass approximately twice that of the proton (weighted mean of 3817 plus or minus 167 m/sub e/) which decays in flight with emission of a 70-Mev pi /sup -/. Its presence in a K/sup -/ interaction leads to an attribution of strangeness-1 and baryonic number 2. The time of flight was 2 x 10/sup -10/ sec. Using the scheme of known particles, the most reasonable interpretation of the event is that it is a ( SIGMA /sup -/n) hyperfragment. (C.J.G.) ISSN 00296341 Educational Use Research Learning Resource Type Article Publisher Date 1959-08-16 Publisher Department Istituto Nazionale di Fisica Nucleare, Milan Journal Nuovo Cimento Volume Number 13 Organization Istituto Nazionale di Fisica Nucleare, Milan