The photonuclear cross section at high energies as determined from the nuclear interaction of muons

Abstract

Information about the photonuclear cross section σγ, at high energy can be obtained from muon interaction experiments by considering the virtual photon spectrum of the muons. Previous attempts to fit a virtual photon spectrum and form factor to the following experiments are discussed: (1) interaction of machine-produced muons at 2.5 and 5 GeV; (2) interaction of cosmic-ray muons at high energy; (3) the intensity–depth relation of cosmic-ray muons deep underground. It is shown that previous proposals to fit one or more of these experiments are not consistent with all the experimental evidence, particularly in relation to the form factor. It is demonstrated that σγ is energy-dependent above 1 GeV and, with due allowance for this, a form factor may be found which is consistent with the various experiments.