The Gamma Factory proposal for CERN

This year, 2015, marks the centenary of the publication of Einsteins Theory of General Relativity and it has been named the International Year of Light and light-based technologies by the UN General Assembly. It is thus timely to discuss the possibility of broadening the present CERN research program by including a new component based on a novel concept of the light source which could pave a way towards a multipurpose Gamma Factory. The proposed light source could be realized at CERN by using the infrastructure of the existing accelerators. It could push the intensity limits of the presently operating light-sources by at least 7 orders of magnitude, reaching the flux of the order of 10^17 photons/s, in the particularly interesting gamma-ray energy domain of 1 < Ephoton < 400 MeV. This domain is out of reach for the FEL-based light sources. The energy-tuned, quasi-monochromatic gamma beams, together with the gamma-beam-driven, high intensity secondary beams of polarized positrons, polarized muons, neutrons and radioactive ions would constitute the basic research tools of the proposed Gamma Factory. The Gamma Factory could open new research opportunities in a vast domain of uncharted fundamental physics and industrial application territories. It could strengthen the leading role of CERN in the high energy frontier research territory by providing the unprecedented-brilliance secondary beams of polarized muons for the TeV-energy-scale muon collider and the polarized- muon-beam based neutrino factory.Comment: An Executive Summary of the Gamma Factory proposal addressed to the CERN management. 6 page

Selected design issues of a dedicated facility for generic QCD studies

QCD, even if presently out of fashion, deserves a dedicated, generic research program providing new challenges for the theory and aiming at understanding hadronic matter and vacuum in terms of quark and gluon degrees of freedom. Such a research program needs a dedicated facility to re-address basic questions which remain unanswered and to open new vistas.Comment: 5 pages, 4 figures, talk at Workshop on the Spin Structure of the Proton and Polarized Collider Physic

Ascertaining the origin of the lνlνl\nu l\nu excess events at the LHC by a change of beam energy

A higher than predicted rate of two leptons plus missing transverse energy events, reported at the summer HEP conferences, can originate from a decay of the Higgs boson into a $WW^{(*)}$ pair, a misjudgement of the rate of SM background processes or a statistical fluctuation. In this paper we discuss a way to resolve this three-fold ambiguity.Comment: 10 pages, 4 figures, version 2: Fig. 1 removed to comply with the ATLAS policy rule

The LHC excess of four-lepton events interpreted as Higgs-boson signal: background from Double Drell--Yan process?

We construct a simple model of the Double Drell--Yan Process (DDYP) for proton--proton collisions and investigate its possible contribution to the background for the Higgs-boson searches at the LHC. We demonstrate that under the assumption of the predominance of short range, ${\cal O}(0.1)\,$fm, transverse-plane correlations of quark--antiquark pairs within the proton this contribution becomes important and may even explain the observed excess of the four-lepton events at the LHC -- the events interpreted as originating from the Higgs-boson decays: $H \rightarrow ZZ^{*} \rightarrow 4l$ and $H \rightarrow WW^{*} \rightarrow 2l 2 \nu$.Comment: 19 pages, 4 figures, Version 2 matches the published versio