The Momentum Spectrum of Cosmic Ray Muons at an angle of 80  to the Zenith at Sea Level

A magnetic spectrograph making use of deflection in a `solid iron' magnet has been used to measure the differential momentum spectrum of cosmic ray muons at sea level for zenith angles close to 80° over the momentum range 1.5 to 40 GeV/ c . The measured spectrum is close to that expected if all the muons come from pions. An analysis is made of the spectrum expected on the basis of muons being derived from charged kaons and conclusions are drawn about the rate of production of charged kaons under certain restrictive assumptions.