Higgs factories
Valery I. Telnov · 2013
Over the past two decades, the high energy physics community has been actively discussing and developing a number of post-LHC collider projects; however, none of them have been approved due to high costs and the uncertainty in post-LHC physics scenarios.There have been great expectations of rich new physics in the 0.1-1 TeV/c 2 mass region: the Higgs boson (one or several), supersymmetry, or perhaps new particles from the dark-matter family.It has been the general consensus that the best machine for the detailed study of new physics to be discovered at the LHC would be an energy-frontier linear e + e -collider.Physicists held their breath waiting for the results from the LHC.In summer 2012, two LHC detectors, ATLAS and CMS, announced the discovery of a Higgs boson with the mass of 126 GeV/c 2 -and (still) nothing else.The absence of new physics in the region below 1 TeV/c 2 has changed the post-LHC collider R&D priorities and triggered a zoo of project proposals for the precision study of the 126 GeV/c 2 Higgs boson, possibly with further upgrades to higher energies.This paper gives an overview of these projects; it is based largely on the reports presented at the first workshop on Higgs factories held at FNAL a few days prior to the present workshop in Protvino.