2004/01/01 by S. R. Klein, Spencer R. Klein, Klein, Spencer R.
Medicine · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear Experiment (nucl-ex) #Particle physics theoretical and experimental studies #Radiation Therapy and Dosimetry #astro-ph #hep-ph #nucl-ex
paper · pdf · doi:10.48550/arxiv.astro-ph/0412546
Presented at "QCD at Cosmic Energies," Erice, Italy, Sept. 29-Oct. 5, 2004. 18 pgs. with 8 figures
arxiv created 2004/12/21 · openalex publication_date 2004/12/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
At very high energies, the Landau-Pomeranchuk-Migdal effect reduces the cross sections for electron bremsstrahlung and photon e+e- pair production. The fractional electron energy loss and pair production cross sections drop as the energy increases. In contrast, the cross sections for photonuclear interactions grow with energy. In solids and liquids, at energies above 1020 eV, photonuclear reactions dominate, and showers that originate as photons or electrons quickly become hadronic showers. These electron-initiated hadronic showers are much shorter (due to the absence of the LPM effect), but wider than purely electromagnetic showers would be. This change in shape alters the spectrum of the electromagnetic and acoustic radiation emitted from the shower. These alterations have important implications for existing and planned searches for radiation from νe induced showers above 1020 eV, and some existing limits should be reevaluated.