The mean transverse momentum of secondaries from cosmic-ray interactions in the region of 2 × 105GeV

Abstract
The variation with separation of the rate of pairs of cosmic-ray muons of energies above 1000 GeV has been measured at a mean angle to the vertical of 45 degrees by Coats et al (1970). The variation is most sensitive to the mean transverse momentum of the parent pions in the initial nucleon-air nucleus interactions and the value determined from comparison with a theoretical analysis is (pt)=0.60+or-0.05 GeV/c, the median primary energy in question being approximately 2 × 105 GeV. The form of the distribution in transverse momentum giving a best fit to the experimental data is that proposed by Elbert et al. (1968). The value found for (pt) lends confirmation to the slow increase in this quantity with increasing interaction energy suggested by previous work.