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Title: STRANGE PARTICLE PRODUCTION IN COMPLEX NUCLEI. Technical Report No. 22 on COSMIC RAY AND ELEMENTARY PARTICLES GROUP

Technical Report ·
OSTI ID:4277680

Strange particle production by high-energy pions and protons bombarding carbon, iron, and lead nuclei in a multiplate cloud chamber was investigated. This choice of targets provided an opportunity to compare the effects of multistage processes which are sensitive to nuclear radius. The two stage process that oringinally motivated the experiment was the indirect production of strange particles by pions in turn produced by a nucleon incident on the same nucleus. Early indications of very low direct production of strange particles in p-p collisions led to the belief that a large fraction of the production in p- nucleus collisions was through the indirect process. The value for this fraction in lead is approximates is 2/3. A K-pair production by protons comparable to the direct production of hyperon-K meson pairs by protons was also observed. To have a quantitative knowledge of the strange particle production by a known pion beam in nuclear matter, the same targets to 1.5 Bev pi /sup -/ mesons as well as 2.8 Bev protons were exposed. This data also yielded interesting comparisons on the effects of other multistage processes, namely the interactions of the strange particles after production. The cross section for the conversion of charged hyperons into neutral hyperons in nuclear interactions seemed to be bigger than geometric. The strange particle production by the pion beam was predominantly direct as shown by a comparison with the bubble chamber studies of pi -nucleon collisions. Total cross sections for strange particle production and distributions in lab angle and energy are presented for the observed strange particles. The multiplate chamber and its auxiliary equipment are described. An improvement in the stability of the cosmotron proton blow-up beam is explained. As part of the analysis of individual events, a least squares fit of measured points to a decay plane is presented in a form suitable for use with a digital computer. (For preceding report see NP-7079.) (auth)

Research Organization:
Princeton Univ., N.J. Palmer Physical Lab.; Princeton Univ., N.J. Naval Ordnance Lab.
DOE Contract Number:
NONR-1858(06)
NSA Number:
NSA-13-007949
OSTI ID:
4277680
Report Number(s):
NP-7306
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-59
Country of Publication:
United States
Language:
English