title: Is the electron radiation length constant at high energies?
abstract: Experimental results for the radiative energy loss of 149, 207, and 287 GeV electrons in a thin Ir target are presented. From the data we conclude that at high energies the radiation length increases in accordance with the Landau-Pomeranchuk-Migdal (LPM) theory and thus electrons become more penetrating the higher the energy. The increase of the radiation length as a result of the LPM effect has a significant impact on the behavior of high-energy electromagnetic showers.
authors.affiliation: Department of Physics and Astronomy, University of Aarhus, Denmark.
authors.forename: H D
authors.initials: HD
authors.lastname: Hansen
authors.forename: U I
authors.initials: UI
authors.lastname: Uggerhøj
authors.forename: C
authors.initials: C
authors.lastname: Biino
authors.forename: S
authors.initials: S
authors.lastname: Ballestrero
authors.forename: A
authors.initials: A
authors.lastname: Mangiarotti
authors.forename: P
authors.initials: P
authors.lastname: Sona
authors.forename: T J
authors.initials: TJ
authors.lastname: Ketel
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Vilakazi