Muon Production in Relativistic Cosmic-Ray Interactions
arXiv:0907.4799 · doi:10.1016/j.nuclphysa.2009.10.128
Abstract
Cosmic-rays with energies up to eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy ( 1 TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon decays and from charm production in the atmosphere. Terrestrial experiments are most sensitive to far-forward muons so the production rates are sensitive to high- partons in the incident nucleus and low- partons in the nitrogen/oxygen targets. Muon measurements can complement the central-particle data collected at colliders. This paper will review muon production data and discuss some non-perturbative (soft) models that have been used to interpret the data. I will show measurements of TeV muon transverse momentum () spectra in cosmic-ray air showers from MACRO, and describe how the IceCube neutrino observatory and the proposed Km3Net detector will extend these measurements to a higher region where perturbative QCD should apply. With a 1 km surface area, the full IceCube detector should observe hundreds of muons/year with in the pQCD regime.
4 pages, 2 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee. Tweaked formatting at organizers request