A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector

摘要

The physics programme and the design are described of a new collider forparticle and nuclear physics, the Large Hadron Electron Collider (LHeC), inwhich a newly built electron beam of 60 GeV, up to possibly 140 GeV, energycollides with the intense hadron beams of the LHC. Compared to HERA, thekinematic range covered is extended by a factor of twenty in the negativefour-momentum squared, $Q^2$, and in the inverse Bjorken $x$, while with thedesign luminosity of $10^{33}$ cm$^{-2}$s$^{-1}$ the LHeC is projected toexceed the integrated HERA luminosity by two orders of magnitude. The physicsprogramme is devoted to an exploration of the energy frontier, complementingthe LHC and its discovery potential for physics beyond the Standard Model withhigh precision deep inelastic scattering measurements. These are designed toinvestigate a variety of fundamental questions in strong and electroweakinteractions. The physics programme also includes electron-deuteron andelectron-ion scattering in a $(Q^2, 1/x)$ range extended by four orders ofmagnitude as compared to previous lepton-nucleus DIS experiments for novelinvestigations of neutron's and nuclear structure, the initial conditions ofQuark-Gluon Plasma formation and further quantum chromodynamic phenomena. TheLHeC may be realised either as a ring-ring or as a linac-ring collider. Opticsand beam dynamics studies are presented for both versions, along with technicaldesign considerations on the interaction region, magnets and furthercomponents, together with a design study for a high acceptance detector. Civilengineering and installation studies are presented for the accelerator and thedetector. The LHeC can be built within a decade and thus be operated while theLHC runs in its high-luminosity phase. It thus represents a major opportunityfor progress in particle physics exploiting the investment made in the LHC.