Related papers: Photon collider at TESLA: parameters and interacti…
The advent of back-scattered laser beams for electron-positron colliders will allow detailed studies of a large array of high energy photon-photon and photon-electron collision processes with polarized beams. These include tests of…
A method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. The ultimate transverse emittances are much below those achievable by…
Construction of future electron-positron colliders (or dedicated electron linac) and muon colliders (or dedicated muon ring) tangential to Future Circular Collider (FCC) will give opportunity to utilize highest energy proton and nucleus…
Locating the gamma-ray emission sites in blazar jets is a long-standing and highly controversial issue. We investigate jointly several constraints on the distance scale r and Lorentz factor Gamma of the gamma-ray emitting regions in…
Photonic events with large missing energy have been observed in e+e- collisions at centre-of-mass energies of 130, 136, 161 and 172 GeV using the OPAL detector at LEP. Results are presented based on search topologies designed to select…
The production rate and kinematics of photons produced in association with Z bosons are studied using 2/fb of p\bar{p} collision data collected at the Collider Detector at Fermilab. The cross section for p\bar{p} -> l^+ l^- gamma + X (where…
Recently, a $\gamma\gamma$ collider based on the existing 17.5 GeV linac of the European XFEL has been proposed. High-energy photons will be generated by Compton scattering of laser photons with a wavelength of 0.5-1 $\mu$m on electrons.…
We discuss the production, at high--energy e$^+$e$^-$ linear colliders, of new heavy fermions predicted by extensions of the Standard Model. We analyze in great details the various signals and the corresponding backgrounds for both pair…
We will summarize some aspects of the standard model Higgs boson at high energy $\gamma\gamma$ colliders, where the photon beams are realized by the laser backscattering method, including the direct Higgs boson production via…
Construction of the TESLA linear electron-positron collider tangentially to the HERA proton ring will provide a number of new facilities for particle and nuclear physics research. In this paper main parameters and physics goals of eA,…
We present a numerical estimate of the $\gamma^* \gamma^*$ total cross section at the designed 500 GeV $e^+e^-$ Linear Collider, based upon the BFKL Pomeron. We find that the event rate is substantial provided electrons scattered under…
We study the processes \gamma \e -> \gamma \e and \gamma \gamma -> \gamma \gamma, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff $M_S \sim 1$ TeV for the…
We study the production of a J/psi meson in association with one or two jets in gamma gamma collisions concentrating on the direct-photon contribution, which is expected to be dominant for large J/psi-meson transverse momentum and/or large…
Gamma-rays from cosmological sources contain information about gamma-ray interactions. Standard model and non-standard model photon interactions along the path between the source and the observer can lead to changes in the energy or state…
We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu W through the angular and energy spectrum of the secondary leptons. Within the narrow-width approximation, a semi-analytical study of the secondary lepton…
The potential of LC+HERA based gamma-p collider to probe WW-gamma vertex is presented through the discussion of sensitivity to anomalous couplings and p_{T} distribution of the final quark. The limits of -0.16<(kappa-1)<0.14,…
The physics potential is briefly summarized for an e+e- linear collider operating at center-of-mass energies up to \sqrt{s} = 1 TeV and delivering integrated luminosities up to \int L = 0.5 ab^(-1) in one to two years. This machine will…
The Fermi LAT discovery that classical novae produce >100 MeV gamma-rays establishes that shocks and relativistic particle acceleration are key features of these events. These shocks are likely to be radiative due to the high densities of…
This report presents a review of the studies made in the working group on gamma gamma and e gamma physics" of the ECFA/DESY workshop on linear collider physics. It reports on several new physics studies, in particular s-channel Higgs…
A strong laser field and the Coulomb field of a nucleus can produce e^{+}e^{-} pairs. It is shown for the first time that there is a large probability that electrons and positrons created in this process collide after one or several…