This document provides input from the CLIC e+e- linear collider studies to the update process of the European Strategy for Particle Physics. It is submitted on behalf of the CLIC/CTF3 collaboration and the CLIC physics and detector study. It describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale e+e- linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technique. A high-luminosity high-energy e+e- collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a \sim125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear e+e- collider built and operated in centre-of-mass energy stages from a few-hundred GeV up to a few TeV will be an ideal physics exploration tool, complementing the LHC. Two example scenarios are presented for a CLIC accelerator built in three main stages of 500 GeV, 1.4 (1.5) TeV, and 3 TeV, together with the layout and performance of the experiments and accompanied by cost estimates. The resulting CLIC physics potential and measurement precisions are illustrated through detector simulations under realistic beam conditions.
Measurement of the H to ZZ branching fraction at 350 GeV and 3 TeV CLIC
在本文中，我们调查的前景，测量分支分数的标准模型希格斯玻色子衰变到一对$Z$玻色子在未来的紧凑型线性对撞机（CLIC）在350 GeV和3 TeV的质心能量。使用CLIC探测器的详细模拟进行研究，同时考虑到所有相关的物理和光束诱导的背景过程。结果表明，在质心能量为350 GeV（3 TeV）时，假设积分亮度为1 ab $^{-1}$（5 ab $^{-1}$），用半轻子末态可以测量出Higgs产生截面和分支分数BR的乘积（${H\rightarrow\thinspace ZZ^\ast}$），相对统计不确定度为20%（3.0%）.
MEASUREMENT OF THE HIGGS BRANCHING RATIO BR($H\rightarrowγγ$) AT 3 TeV CLIC
在本文中，我们解决了潜在的3 TeV的质心能量紧凑型直线对撞机（CLIC）来测量希格斯玻色子衰变到两个光子的分支分数，BR（$H\rightarrowγγ$）。由于光子是无质量的，希格斯玻色子与光子的耦合是通过涉及标准模型或超越标准模型的重粒子的高阶过程实现的。任何测量到的BR（$H\rightarrowγγ$）的偏差，以及因此希格斯耦合$g_{Hγγ}$与标准模型预测的偏差，都可能表明新物理学。因此，希格斯衰变为两个光子是对希格斯扇区的一个有趣的探测。这项研究是使用模拟CLIC的检测器，并考虑到所有相关的物理和光束诱导过程中的一个完整的重建链。结果表明，假设5 ab $^{-1}$和非偏振光束的积分光度，可以测量$W^+W^-$聚变和BR中Higgs产生截面的乘积（$H\rightarrowγγ$），其相对统计不确定度为5.5%.
Simulation of an Intra-Pulse Interaction Point Feedback for Future Linear Colliders
在未来的正常传导线性对撞机中，光束将以100 ns量级的短脉冲串形式传输。脉冲将由几毫秒分开。为了保持高亮度，反馈是必要的脉冲到脉冲的基础上。此外，可以在一个脉冲内校正光束位置和角度的脉冲内反馈似乎在技术上是可行的。针对NLC（Next Linear Collider）和CLIC（Compact Linear Collider），对不同反馈方案的可能性能进行了仿真。
Emittance reduction with variable bending magnet strengths: Analytical optics considerations and application to the Compact Linear Collider damping ring design
