Study of pp to gamma +anything at the ISR at E/sub cm/=444 GeV and its implications for pi /sup 0/ production and multiplicity

The angular and momentum distributions of gamma -rays, produced in pp collisions at the CERN ISR at a centre of mass centre of 44.4 GeV, have been measured using nuclear emulsions. This experiment covers an angular region 27 degrees < theta /sub cm/<88 degrees which had not been covered in an earlier ISR experiment (Neuhofer et al. (1972)). Using the entire available gamma -ray data, the pi /sup 0/ angular distribution has been deduced. The average pi /sup 0/ multiplicity is found to be (N/sub pi /)=4.0+or-0.6 ( pi = pi /sup 0/). Using this value, we deduce the average charged particle multiplicity to be (N /sub ch/)=10.6+or-1.4. (6 refs).