2000/12/24 by M. A. Moinester, Murray Moinester, Moinester, Murray
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Superconducting Materials and Applications #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0012063
13 pages, 3 figures, Invited Talk at the APS DNP Town Meeting on Electromagnetic & Hadronic Physics, Dec. 2000, Jefferson Lab., including evaluations submitted to APS DNP Town Meeting White Paper Committee
arxiv created 2000/12/24 · openalex publication_date 2000/12/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
CERN COMPASS can investigate pion-photon interactions, to achieve a unique Primakoff Coulomb physics program, centered on pion polarizability and hybrid meson structure studies. COMPASS uses 100-280 GeV beams (muon, pion) and a virtual photon target, and magnetic spectrometers and calorimeters to measure the complete kinematics of pion-photon reactions. The COMPASS experiment is scheduled to begin data runs in 2001. Pion polarizabilities and hybrid mesons can be studied via the Primakoff reactions pion + gamma ---> pion + gamma and pion + gamma ---> Hybrid. The electric (alpha) and magnetic (beta) pion and Kaon polarizabilities characterize their deformation in an electromagnetic field, as occurs during gamma-pion Compton scattering. They depend on the rigidity of their internal structures as composite particles, and are therefore important quantities to test the validity of theoretical models. The polarizability measurement will provide an important new test of QCD chiral dynamics. The studies of quark-antiquark-gluon hybrid mesons would improve our understanding of these exotic mesons. COMPASS may improve previous Primakoff polarizability and Hybrid studies by two to three orders of magnitude. Appendixes A (Pion and Kaon Polarizabilities at COMPASS) and B (Hybrid Meson Structure at COMPASS) of this contribution include evaluations submitted to the APS DNP Town Meeting White Paper Committee. These summarize (1) the fundamental scientific issues addressed, (2) major achievements since the last DNP long range plan, (3) the short and long term U.S. outlook, (4) comparison of U.S. and global effort, (5) other issues.