C$^3$: A "Cool" Route to the Higgs Boson and Beyond

Abstract

We present a proposal for a cold copper distributed coupling accelerator that can provide a rapid route to precision Higgs physics with a compact 8 km footprint. This proposal is based on recent advances that increase the efficiency and operating gradient of a normal conducting accelerator. This technology also provides an e + e − collider path to physics at multi-TeV energies. In this article, we describe our vision for this technology and the near-term R&D program needed to pursue it.

C$^3$ Demonstration Research and Development Plan

“…C 3 is an opportunity to realize an e + e − collider for the study of the Higgs boson at √ s = 250 GeV, with a well defined upgrade path to 550 GeV while staying on the same short facility footprint [1,2]. C 3 is based on a fundamentally new approach to normal conducting linear accelerators that achieves both high gradient and high efficiency at relatively low cost.…”

“…C 3 is based on a fundamentally new approach to normal conducting linear accelerators that achieves both high gradient and high efficiency at relatively low cost. This design is described in [2]. The primary goal of the C 3 Demonstration R&D Plan is to reduce technical and cost risk by building and operating the key components of C 3 at an adequate scale.…”

Strategy for Understanding the Higgs Physics: The Cool Copper Collider

“…The Cool Copper Collider (C 3 ) [5] is a relatively new proposal to build a Higgs Factory with a 250 GeV energy collision energy based on a technology that offers the option for an adiabatic upgrade to 550 GeV, and possible extension to the TeV-scale. Beam parameters for C 3 -250 and C 3 -550 are given in Table 1.…”

“…The linac is cooled to ≈ 80 K by liquid nitrogen to reduce the RF power requirements, and increase the acceleration gradient, upwards of 150 MeV/m [6,7]. Thus, the acceleration gradient of the C 3 linacs [5] is an order of magnitude increase over the SLC, a factor 4 over that of the ILC[2], and a factor of two over the normal-conducting NLC design [8]. The C 3 plans to reuse the final focus design of the ILC, which is optimized for up to 1 TeV operation, recouping much of the progress made in its design.…”

A single-crystal alkali antimonide photocathode: high efficiency in the ultra-thin limit

“…Dense and coherent electron beams generated via photoemission have enabled many revolutionary tools in the physical sciences. These include x-ray free electron lasers with 10 9 times higher peak x-ray brightness than previous sources [1,2], ultrafast electron microscopes that achieve femtosecond temporal and atomic structural resolution [3,4], hadron collider luminosity-enhancing systems based on electron beams [5], and next-generation electron linear colliders [6,7], which will probe physics beyond the standard model. Electron beam brightness, defined as the density of the beam in position-momentum phase space, is a central figure of merit for each of these applications [8].…”