Photon collider (gamma-gamma, gamma-e), PLC, proposed in 1981, was discussed at all LC workshops as a very natural addition to linear e+e-colliders, since the beams are used only once. I will recall the physical motivation and possible parameters of the PLC and what needs to be foreseen in the design of the collider in order to have the PLC in the future (or from the very beginning?).
We consider a gamma-gamma collider with W<12 GeV based on 17 GeV linac of the EU XFEL. High-energy photons will be obtained by Compton scattering of 0.5 μm laser photons on the existing 17.5 GeV electron beams. Such a collider would be an excellent place for the development and application of modern technologies needed for the PLC: powerful lasers, optical cavities and low-emittance electron...
Potential physical studies feasible with the ILD experiment operating in the e-e- mode at the ILC collider are discussed. A data sample of about 100 fb-1 collected at the e-e- collisions will allow to search for a few specific processes beyond the Standard model. A high sensitivity can be achieved for the processes proceeding through the t-channel exchange of Majorana neutrino, e-e- → W-W-,...
It is possible to extend the Higgs sector in the Standard Model (SM) of particle physics in various ways, to resolve some of the open problems in the SM. One of the options is the Georgi-Machacek (GM) model, which introduces SU(2) triplet scalars in a non-trivial way. We revisit doubly-charged Higgs boson production processes in the GM model at electron-electron colliders and compare them with...
Though leptoquarks have gained much attention in recent time due to their ability to explain various flavour anomalies, their existence is not confirmed yet experimentally [1]. But, we find that zeros of single photon tree level amplitude [2,3] have the potential to provide information about leptoquarks (if any) at electron-photon collider [4]. It is a well known fact that the tree-level...
