Related papers: Effective photon spectra for Photon Colliders
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.…
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an electron-electron or…
The possibility of a photon collider extension to the beam dump of the $17.5$ GeV European XFEL has already been discussed before as the first high energy collider of its sort. It would not only be the first proof of concept and test of a…
Typical observational gamma-ray burst (GRB) spectra are discussed and, in this connection, what is the origin of the compactness problem and how it was solved at first. If the threshold for $e^{-}e^{+}$ pair production depends on an angle…
Spectrograph is an optical device that is used to disperse photons of different energies $E$ into distinct directions and space locations, and to take a snapshot of the whole spectrum of photon energies with a spatially sensitive photon…
Particles with energies below the mean energy $E_0$ in relativistic shocked plasmas should assume an equilibrium energy distribution. This leads to a synchrotron spectrum $F_\nu \propto \nu^{1/3}$ up to approximately the critical frequency…
In this work, a constant and uniform magnetic field is less than the Schwinger critical value. In turn, an additional constant and uniform electric field is taken much smaller than the magnetic field value. The propagation of a photon in…
The energy spectrum for high energy $\gamma$-rays ($E_\gamma \geq 10$ MeV) from the process $pp \to \gamma \gamma X$ emitted at $90^0$ in the laboratory frame has been measured at 216 MeV. The resulting photon energy spectrum extracted from…
Usually, the emission of low-energy photons in electron-positron (or electron-ion) bunch collisions is calculated with the same approach as for synchrotron radiation (beamstrahlung). However, for soft photons (E_gamma < E_c where E_c is a…
We provide an introduction to complex photonic media, that is, composite materials with spatial inhomogeneities that are distributed over length scales comparable to or smaller than the wavelength of light. This blossoming field is firmly…
We calculate the cross section for inclusive prompt photon production in $\gamma\gamma$ collisions, i.e. the reaction $e^+e^-\to \gamma \gamma \to \gamma X$, in next-to-leading order QCD. We show that at LEP2 energies this cross section is…
For the first time, the production of a massive dark photon (DP) in the $\gamma e^-$ scattering at the future lepton colliders ILC, CLIC, and CEPC is examined. The invisible decay mode of the DP is addressed. We have studied both the…
We propose and demonstrate that a gamma-gamma collider with W_gg < 12 GeV can be added to the European XFEL with a minimal disruption to its main program. High-energy photons will be obtained by Compton scattering of 0.5 micron laser…
High intensity laser facilities are expanding their scope from laser and particle-acceleration test beds to user facilities and nuclear physics experiments. A basic goal is to confirm long-standing predictions of strong-field quantum…
Previous studies of the kinematic coverage for measuring the photon structure function F_2^gamma at a future 500 GeV e^+e^- linear collider are updated using current estimates of luminosities and important detector parameters. The…
Employing the linear sigma model, the effective masses of quasi-particle excitations are found to exhibit significant variations within the phase diagram, which has a critical point at non-zero chemical potential, where a first-order phase…
We point out a few remarkable properties of the $\gamma\gamma\to\gamma\gamma$ process at high energy. They should allow to search for effects of new particles and interactions. We give illustrations with threshold effects due to pairs of…
In this report on Photon Colliders the following technical aspects are considered: special requirements to an accelerator, new ideas on laser optics, laser cooling, and interaction region layout issues. In fact it is continuation of my…
The process e^+e^- -> gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb^{-1} taken at centre-of-mass energies of 130-172 GeV. The…
A linear electron-positron collider operating at TeV scale energies will provide high precision measurements and allow, for example, precision studies of the Higgs boson as well as searches for physics beyond the standard model. A future…