2004/06/09 by NA Collaboration, NA59 Collaboration, A. Apyan +68
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Laser Design and Applications #Laser-Matter Interactions and Applications #Spectroscopy and Quantum Chemical Studies #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0406026
8 pages, 7 figures, REVTeX4 two column, Version for publication
openalex publication_date 2004/06/09 · arxiv created 2004/06/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present new results regarding the features of high energy photon emission by an electron beam of 178 GeV penetrating a 1.5 cm thick single Si crystal aligned at the Strings-Of-Strings (SOS) orientation. This concerns a special case of coherent bremsstrahlung where the electron interacts with the strong fields of successive atomic strings in a plane and for which the largest enhancement of the highest energy photons is expected. The polarization of the resulting photon beam was measured by the asymmetry of electron-positron pair production in an aligned diamond crystal analyzer. By the selection of a single pair the energy and the polarization of individual photons could be measured in an the environment of multiple photons produced in the radiator crystal. Photons in the high energy region show less than 20% linear polarization at the 90% confidence level.