The International Linear Collider Technical Design Report - Volume 2: Physics
Howard Baer, Tim Barklow, Keisuke Fujii, Yuanning Gao, Andre Hoang, Shinya Kanemura, Jenny List, Heather E. Logan, Andrei Nomerotski, Maxim Perelstein, Michael … 展开作者
Howard Baer, Tim Barklow, Keisuke Fujii, Yuanning Gao, Andre Hoang, Shinya Kanemura, Jenny List, Heather E. Logan, Andrei Nomerotski, Maxim Perelstein, Michael E. Peskin, Roman Pöschl, Jürgen Reuter, Sabine Riemann, Aurore Savoy-Navarro, Geraldine Servant, Tim M. P. Tait, Jaehoon Yu
The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.
The Linear Collider Physics Case: International Response to the Technology Independent Questions Posed by the International Technology Recommendation Panel
The signals of the SO(5) \times U(1) gauge-Higgs unification model at the International Linear Collider are studied. In this model, Kaluza-Klein modes of the neutral gauge bosons affect fermion pair productions. The deviations of the forward-backward asymmetries of the $e^+e^-\to \bar{b}b$, $\bar{t}t$ processes from the standard model predictions are clearly seen by using polarised beams. The deviations of these values are predicted for two cases, the bulk mass parameters of quarks are positive and negative case.
We present the full O(alpha) electroweak radiative corrections to 9 Higgs boson production with the beam polarization at the International Linear Collider(ILC). The computation is performed with the help of GRACE-Loop. We compared the full O(alpha) electroweak radiative corrections with the factorized initial state radiation(ISR) effects to estimate the pure weak corrections. This reveals the pure weak corrections are not negligible and should be taken into account for the precision measurements of the Higgs boson property at the ILC experiments.
In this paper we study double vector meson production in $γγ$ interactions at high energies and, using the color dipole picture, estimate the main observables which can be probed at the International Linear Collider (ILC). The total $γ(Q_1^2) + γ(Q_2^2) \rightarrow V_1 + V_2$ cross-sections for $V_i = ρ$, $ϕ$, $J/ψ$ and $Υ$ are computed and the energy and virtuality dependencies are studied in detail. Our results demonstrate that the experimental analysis of this process is feasible at the ILC and it can be useful to constrain the QCD dynamics at high energies.
国际直线对撞机（International Linear Collider，ILC）是一台初始质心能量为500 GeV，随后可扩展到1 TeV的正负电子对撞机，其目标是以前所未有的高灵敏度研究TeV量级的物理。主要议题包括希格斯粒子性质的精确测量，超对称粒子的研究和潜在的理论结构，如果超对称性在自然界中被实现，探索质量起源的其他可能性，以及宇宙学的联系。在许多通道中，特别是希格斯和轻子部分，ILC比LHC更敏感，并且总体上与LHC互补。在这篇简短的文章中，我们将快速了解ILC的功能。
Lepton flavor violating (LFV) process $e^+ e^- \to e^+ τ^-$ induced by the four-Fermi contact interactions at the International Linear Collider (ILC) is studied. Taking account of the event selection conditions, it is shown that the ILC is sensitive to smaller LFV couplings as compared to the measurement of $τ\to 3e$ process at the B-factory experiment. The upper bounds on some of the LFV couplings are improved by several factors using polarized $e^-/e^+$ beams at $\sqrt{s}=250~\mathrm{GeV}$ and by an order of magnitude at $\sqrt{s}=1~\mathrm{TeV}$.
The talk summarises the case for Higgs physics in $e^+e^-$ collisions and explains how Higgs parameters can be extracted in a model-independent way at the International Linear Collider (ILC). The expected precision will be discussed in the context of projections for the experiments at the Large Hadron Collider (LHC).
The signature of heavy fermionic triplets belonging to Type III seesaw at the International Linear Collider (ILC) is probed. Presence of charged fermionic triplets upto a mass of about $ 750$ GeV could be established through single production at a 1 TeV ILC with moderate luminosity of 300 fb$^{-1}$, assuming a fermion triplet-electron mixing of about 0.05. Unlike the case of LHC, the production process is highly sensitive to the mixing, making the process interesting. The single production of neutral triplet is found to be somewhat harder, considering the large SM background present. Pair prod…
"Light" Higgs and warped models: Case for a Gigantic International Hadron Collider
大型强子对撞机似乎有了一个重大发现，质量约为125 GeV的类希格斯粒子，其性质类似于标准模型希格斯粒子。在扭曲的味道理论的背景下，这在理论上是非常有吸引力的，这表明卡鲁扎-克莱因粒子的质量很可能超过10 TeV，除了可能的镭。从SM情景之外的其他有趣的角度来解释SM-样希格斯粒子也可能是相关的尺度高于LHC所能达到的尺度。鉴于这些发展，更深入地了解味道和其他基本问题需要一个巨大的国际强子对撞机[GIHC]，也许与厘米能量的$\approx$ 100 TeV \cite{2talks}。建议{ \it global effort}应用于构造此机器以解决SM无法回答的许多问题。
A dark Z is a massive Abelian gauge boson which is coupled to the Standard Model through both kinetic and mass mixing with the electroweak sector. We study the phenomenology of the dark Z at an energy-frontier electron-positron collider, such as the proposed International Linear Collider (ILC). We show that precision electroweak constraints and the current bounds from the hadron colliders allow a dark Z that is kinematically accessible at the ILC with 250 GeV or 500 GeV center-of-mass energy. Further, the reach of the ILC searches for a dark Z significantly exceeds the expected reach of the hi…
Rare Decay of the Top t->c l lbar and Single Top Production at International Linear Collider
本文在单圈水平上，对标准模型、双Higgs双重模型（I和II）和MSSM中的变味中性流稀有顶夸克衰变t-> cl+l-和t->c nu_i bar nu_i进行了全面详细的分析。所有模型的分支比都非常小，为O（10^-14），除了无约束MSSM的情况，在无约束MSSM中，e+e-和nu_i bar nu_i的分支比可以达到O（10^-6），tau+ tau-的分支比可以达到O（10^-5）。这个分支比与t-> cV，cH的分支比相当。我们还研究了e+e-> tcbar中的单顶产生率和前后不对称性，并评论了这种信号在国际直线对撞机上的可观测性。
The pair productions of leptons and quarks at $e^+e^-$ Higgs factory are an important probe for new physics via precise measurements. The discovery and exclusion limits of $Z^\prime$ models at the International Linear Collider with $\sqrt{s} = 250$, 500 and 1000 GeV are calculated with selection efficiencies estimated in the existing full simulation studies. It shows a large potential of BSM searches with precise measurements at future energy-frontier $e^+e^-$ colliders.
Discrimination of New Physics Models with the International Linear Collider
大型强子对撞机（LHC）有望提供TeV量级的新物理信号，这可能涉及WIMP暗物质候选者的产生。国际线性对撞机（ILC）将对这些信号进行分类，并引导我们在TeV尺度上找到新物理学的可行模型。本文以惰性Higgs模型、超对称Higgs模型和具有T宇称的最小Higgs模型为例，讨论了ILC如何鉴别新的物理模型。这些模型预测了具有不同自旋的暗物质粒子，分别为0、1/2和1，因此包括代表性的场景。具体来说，我们专注于对生产过程，e+e-> chi+chi- -> chi 0 chi 0 W +W-，其中chi 0和chi+-是WIMP暗物质和一个新的带电粒子在这些模型中预测。然后，我们评估如何准确地确定这些新粒子的性质，可以在ILC和证明，ILC是能够识别新的带电粒子的自旋和歧视这些模型。
This presentation gives the prospects of measuring the general Lorentz structures of $VVH$ ($V=Z$, $γ$ and $W$) couplings at the International Linear Collider (ILC). Sensitivities to Higgs CP-even and CP-odd structures are evaluated by using various Higgs production channels and employing measurements of kinematical distributions. The evaluation is performed based on full detector simulation of the International Large Detector (ILD) at center-of-mass energies $\sqrt{s}=$ 250 and 500 GeV. Combined sensitivities on the anomalous $ZZH$ couplings are provided for a realistic operating scenario of …
The Georgi-Machacek (GM) model is one of many Beyond Standard Model scenarios with an extended scalar sector which can group under the custodial $\rm SU(2)_C$ symmetry into a fiveplet, a triplet, and two singlets. The heavy charged custodial fiveplet Higgs $\rm H_5^{\pm}$ are typical particles in GM model which couple to the electroweak gauge bosons, therefore provide a good testing ground for the detection of the $\rm H^\pm W^\mp Z$ vertex. The neutral custodial fiveplet Higgs $\rm H_5^{0}$ in the GM model has the same mass with $\rm H_5^{\pm}$ and couples to the electroweak gauge bosons $\rm…
Weakly Interacting Massive Particles (WIMPs, $χ$) are candidates for Dark Matter. WIMP searches at lepton colliders are complementary to searches at hadron colliders and direct and indirect detection, since they directly probe the coupling to electrons which a priori is independent of the coupling to hadrons. Like at hadron colliders, WIMP pair production can be observed via an additional tag particle, in particular a photon from initial state radiation ($e^+e^-\rightarrowχχγ$). With this technique WIMP masses to nearly half the centre-of-mass energy can be probed. Polarised beams are essentia…
The International Linear Collider (ILC) is a proposed electron -- positron collider with a collision energy of $\sqrt{s}$ = 500 GeV in the baseline configuration. The ILC physics program takes full advantage of the fact that the machine can be operated at arbitrary energy from the maximum down to the peak of the ZH production cross section near $\sqrt{s}$ = 250 GeV or below. It will advance our understanding of nature through precision measurements of Standard Model parameters, detailed study of the Higgs sector, and a comprehensive search for new phenomena that extends beyond the purely kinem…
We present a systematical study on the prompt $J/ψ$ production in association with a $c\bar{c}$ pair via the process, $γγ\to H(c\bar{c}) +c+\bar{c}$, within the framework of non-relativistic QCD at the future high-energy $e^{+}e^{-}$ collider - International Linear Collider (ILC), including both direct and feed-down contributions. For direct $J/ψ$ production, the states with color-octet channels, especially the $^3P_J^{[8]}$ and $^1S_0^{[8]}$ ones, provide dominant contribution to the production cross-section, which are about fifty-two times over that of the color-singlet one. This is clearly …
Measuring Anomalous Couplings in H->WW* Decays at the International Linear Collider
测量希格斯玻色子与W玻色子的耦合是对我们理解电弱对称性破缺机制的一个重要检验。利用ZH -> nu nu WW* -> nu nu 4j事例研究了国际直线对撞机（ILC）对HW+W-反常耦合的敏感性。利用有效的拉格朗日方法，我们计算了希格斯玻色子的微分衰变率，包括新的5维算子的影响。我们提出了一个蒙特卡罗模拟的事件在ILC，使用一个完整的检测器模拟的基础上geant 4和一个真正的事件重建链。预期的异常耦合的约束条件。
We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.
The document is prepared for the LCWS2016 conference proceedings. The expected status of Higgs physics at the end of Run-3 is presented. The current Run-2 status is briefly reviewed, and the expected Higgs reach after the HL-LHC period is also summarized for some channels.
The International Linear Collider is now proposed with a staged machine design, with the first stage at $\sqrt{s}=$~250 GeV and an integrated luminosity goal of 2~ab$^{-1}$. One of the questions for the machine design is the importance of positron polarization. In this report, we review the impact of positron polarization on the physics goals of the $250$ GeV stage of the ILC and demonstrate that positron polarization has distinct advantages.
In this study, the sensitivity of future lepton colliders to WIMP dark matter is evaluated assuming WIMP pair production accompanied by a photon from initial state radiation, through which the process can be identified. A full detector simulation for the International Large Detector (ILD) concept at the International Linear Collider (ILC) is performed for a \com energy of 500\,GeV. Energy scales of up to $3$\,TeV can be tested for different effective operators for WIMP masses almost up to half the \com energy. The sensitivity benefits from the polarised beams, which can reduce the main SM back…
One of the most interesting channels to search for SUSY is the direct pair-production of the $τ$-lepton superpartner, $\widetildeτ$. The $\widetildeτ$ is with high probability the lightest of the scalar leptons, so one of the first SUSY particles that can be observerd, and the signature of $\widetildeτ$ pair production signal events is one of the most difficult ones, yielding to the ``worst'' and so most global scenario for the searches. Analysis performed at LEP set the current model-independent $\widetildeτ$ limits, suffering from the low energy of this facility. Only under strong model assu…
Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This talk will review a number of these scenarios and present the expectations for searches at an electron-positron collider such as the International Linear Collider. The cases discussed include the light Higgsino, the \stau~ slepton in the coannihilation region relevant to dark matter, as well as other SUSY signatures. he studies are based on the ILD concept at the ILC.
Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This talk will review a number of these scenarios and present the expectations for searches at an electron-positron collider such as the International Linear Collider. The cases discussed include the light Higgsino, the \stau~ slepton in the coannihilation region relevant to dark matter, as well as other BSM signatures. The studies are based on the ILD concept at the ILC.
The International Linear Collider is now proposed with a staged machine design, with the first stage at 250 GeV with a luminosity goal of 2 ab-1. In this paper, we review the physics expectations for this machine. These include precision measurements of Higgs boson couplings, searches for exotic Higgs decays, other searches for particles that decay with zero or small visible energy, and measurements of e+e- annihilation to W+W- and 2-fermion states with improved sensitivity. A summary table gives projections for the achievable levels of precision based on the latest full simulation studies.
We study direct searches of additional Higgs bosons in multi-top-quarks events at the LHC Run-II, its luminosity upgraded version with 3000 fb$^{-1}$, and the International Linear Collider (ILC) with the collision energy of 1 TeV. Additional Higgs bosons are predicted in all kinds of extended Higgs sectors, and their detection at collider experiments is a clear signature of the physics beyond the standard model. We consider two Higgs doublet models with the discrete symmetry as benchmark models. If these additional Higgs bosons are heavy enough, the decay modes including top quarks can be domi…
This document is prepared for the LCWS2016 conference proceedings. It reviews the current results on the Higgs CP property measurements from both ATLAS and CMS experiments in the Higgs to diboson decays, and in the Vector Boson Fusion production of Higgs via the ditau decay channel. The projected sensitivity of the ditau signal in HL-LHC is briefly discussed. Finally, it gives the prospects for the CP measurement in the Higgs to ditau decay with the tau substructure developments at both collaborations.
