Axion beams at HERA?

If the recently observed anomaly in the PVLAS experiment is due to the axion, then the powerful beams of synchrotron photons, propagating through high magnetic field of the HERA beamline, become strong axion sources. This gives a unique opportunity of detection of the axion-photon interactions by installing a small detector in the HERA tunnel, and to corroborate the axion hypothesis within a few days of running.Comment: 5 pages, 1 figur

Measurement of the Longitudinal Polarization of the HERA Electron Beam Using Crystals and the ZEUS Luminosity Monitor

A measurement of the longitudinal polarization of the electron beam at HERA utilizing coherent interactions of high energy photons in crystals is proposed. Modification of existing facilities would allow an independent polarization measurement and a verification of birefringence phenomena in crystals for 20--30~GeV photons. Relevant experimental issues and systematic uncertainties are also presented.Comment: 9 pages, latex, 4 figures appended as uuencoded fil

High energy bremsstrahlung at the FCC-ee, FCC-eh and LHeC

Bremsstrahlung spectra will be strongly distorted due to small lateral beam sizes at future colliders. That in turn will have large consequences for the electron and positron beam lifetimes as well as for the luminosity measurements in the case of electron-hadron colliders. We discuss in detail such consequences for the Future Circular Collider and Large Hadron electron Collider cases

High energy photon interactions at the LHC

Experimental prospects for studying high-energy photon-photon and photon-proton interactions at the CERN Large Hadron Collider (LHC) are discussed. Cross sections are calculated for many electroweak and beyond the Standard Model processes. Selection strategies based on photon interaction tagging techniques are studied. Assuming a typical LHC multipurpose detector, various signals and their irreducible backgrounds are presented after applying acceptance cuts. Prospects are discussed for the Higgs boson search, detection of supersymmetric particles and of anomalous quartic gauge couplings, as well as for the top quark physics.Comment: 17 pages, 16 tables and 14 figure