Interactions of 300-GeV protons with tungsten and chromium

Targets consisting of tungsten and chromium powders imbedded in nuclear emulsion were exposed to the 300-GeV proton beam at the Fermi National Accelerator Laboratory. For each event found, the number of minimum-ionizing (shower) tracks n/subs/ and the number of heavily ionizing tracks N/subh/ were determined, and the production angles of the shower tracks were measured. For 39 chromium events, we find < n/subs/ > = 13.8 +- 1.2, < N/subh/ > = 7.2 +- 0.7, and < -ln tan(theta/sub lab//2) > equivalent < r > = 3.32 +- 0.07. For 51 events in tungsten, we find < n/subs/ > = 18.6 +- 1.5, < N/subh/ > = 12.9 +- 1.2, and < r > = 2.83 +- 0.06. The ratio R equivalent < n/subs/ > / < n/subs/ > /subp/, where < n/subs/ > /subp/ is the average charged multiplicity in p-p collisions, agrees with the form R = 1/2 + nu-bar/2, where nu-bar is the mean number of intranuclear collisions. However, no single model adequately explains both the multiplicity and the angular distribution data