A brief overview of the linear collider design is given, with emphasis on the elements of particular importance for the performance. The modifications of the RDR design suggested in the SB2009 proposal are presented, once again with emphasis on those item that have most impact on the performance. In particular, the effects on New Physics channels are studied, by two examples: the analysis of the properties of $\stau$:s in the SUSY benchmark point SPS1a', and the model-independent Higgs recoil mass analysis. It is shown that for both these cases, the SB2009 design performs significantly worse than the RDR design: For the \stau ~analysis, the uncertainties on both the mass and cross-section determination increases by 20 \% (or 35 \% if the travelling focus concept is not deployed). For the Higgs analysis, the corresponding increase in uncertainty is found to be 70 \% both for cross-section and mass (or 100 \% without travelling focus). For both channels, the deterioration is to a large part due to the move of the positron source to the end of the linac.
We study the prospects of searching for leptophilic gauge bosons (LGBs) at the beam dump experiment using $e^\pm$ beams of International $e^+e^-$ Linear Collider (ILC). We consider LGBs in association of $U(1)_{e-μ}$, $U(1)_{e-τ}$, and $U(1)_{μ-τ}$ gauge symmetries, which are assumed to be light and long-lived. Utilizing the energetic electron and positron beams of the ILC, we show that the ILC beam dump experiment can cover the parameter regions which have not been explored before. We also discuss the possibility of distinguishing various models.
We perform a feasibility study of a beam dump experiment at the International Linear Collider (ILC). To investigate the sensitivity to new light particles at the experiment, we consider models for axion-like particles (ALPs) and a light scalar particle coupled to charged leptons. For both models, we show that the detection sensitivity is almost an order of magnitude higher than other beam dump experiments in the small coupling region. For ALPs, it is shown that the ILC beam dump experiment is highly complementary to bounds from astrophysics. In addition, for the model of the scalar particle, t…
One of the most promising methods to search for axions is a light-shining-through-walls (LSW) experiment. In this work, we discuss the possibility of performing an LSW experiment at the ILC experiment, where photon beams are generated for positron production. The photon beam is energetic and intense; the energy is of order MeV and the number of photons is about $10^{24}$ per year. Due to the high energy and intensity, this LSW experiment can reveal the parameter region of the axion unexplored by previous ground-based experiments.
We study capability of the ILC beam dump experiment to search for new physics, comparing the performance of the electron and positron beam dumps. The dark photon, axion-like particles, and light scalar bosons are considered as new physics scenarios, where all the important production mechanisms are included: electron-positron pair-annihilation, Primakoff process, and bremsstrahlung productions. We find that the ILC beam dump experiment has higher sensitivity than past beam dump experiments, with the positron beam dump having slightly better performance for new physics particles which are produ…
A beam dump experiment can be seamlessly added to the {proposed} International Linear Collider (ILC) program because the high energy electron beam should be dumped after the collision point. The ILC beam dump experiment will provide an excellent opportunity to search for new long-lived particles. Since many of them can be produced by a rare decay of standard model particles, we evaluate spectra of the mesons and $τ$ lepton at the decay based on the PHITS and PYTHIA8 simulations. As a motivated physics case, we study the projected sensitivity of heavy neutral leptons at the ILC beam dump experi…
The SiD concept is one of two proposed detectors to be mounted at the interaction region of the International Linear Collider (ILC). A substantial ILC background arises from low transverse momentum $\mathrm{e}^{+}\mathrm{e}^{-}$ pairs created by the interaction of the colliding beams' electromagnetic fields. In order to provide hermeticity and sensitivity to beam targeting parameters, a forward Beamline Calorimeter (BeamCal) is being designed that will provide coverage down to 5 mrad from the outgoing beam trajectory, and intercept the majority of this pair background. Using the SiD simulation…
We evaluate the neutron and muon fluxes produced in the ILC beam dumps by Monte Carlo simulations and discuss their potential use in irradiation fields. We show that the beam dumps can provide high-intensity neutron and muon fluxes with spectra quite similar to secondary cosmic rays, which are suitable for soft error studies. The beam dumps deliver neutrons about $10^{11}$ times the secondary cosmic rays on spaces perpendicular to the beam axis and muons $10^8$ times downstream of the beam dumps in the initial phase of the ILC. Large-area irradiation of 1\,m$^2$ or more is possible. Difference…
ILC正电子系统使用新颖的螺旋波荡器从主电子束产生强大的光子束。该束通过钛靶将其转化为电子-正电子对。目标被构造为以2000 RPM旋转的1 m直径的轮，以将1 ms ILC脉冲训练涂抹超过10 cm。脉冲磁通集中磁体用于提高正电子捕获效率。将其冷却至液氮温度以使1 ms ILC脉冲训练上的磁场的平坦度最大化。我们报告在这个系统上的原型工作。
The Silicon Detector (SiD) is one of the detector concepts for the International Linear Collider (ILC), which is proposed to be built in Japan. Since the decision to reduce the center-of-mass energy for the first stage of the ILC to 250 GeV, numerous efforts are ongoing to evaluate the possible physics program and the change in the detector background. It was found that changing the beam parameters would increase the luminosity and therefore further strengthen the physics outcome. On the downside, the new beam parameters lead to an increase in the detector background arising from beam-beam int…
New Physics in $e^+e^- \rightarrow Z γ$ at the ILC with polarized beams: Explorations beyond conventional anomalous triple gauge boson coupling
在正负电子碰撞中规范玻色子产生的标准模型之外，研究最多的物理信号之一是由于$Z γ$末态的反常三重规范玻色子耦合。在这项工作中，我们研究的影响，这在ILC与偏振光束的信号，超越传统的异常三重中性规范玻色子耦合。在这里，我们报告了一个8维CP保存$Z γZ$顶点，还没有发现在文献中提到。我们进行了系统的研究，在一般条款的异常耦合，并得出一个分类。然后，我们得到的线性顺序分布和没有CP破坏。此外，我们把研究的背景下，一般BSM的相互作用代表的$e^+e^- Z γ$接触相互作用。我们建立了三重规范玻色子耦合与四点接触相互作用之间的对应关系。我们还提出了对这些异常耦合的敏感性，这将是在ILC与现实的偏振和光度。
At this time, the design of the International Linear Collider (ILC) is optimized for e+e- collisions; the photon collider (gamma-gamma and gamma-electron) is considered as an option. Unexpected discoveries, such as the diphoton excess F(750 GeV) seen at the LHC, could strongly motivate the construction of a photon collider. In order to enable the gamma-gamma collision option, the ILC design should be compatible with it from the very beginning. In this paper, we discuss the problem of the beam crossing angle. In the ILC technical design, this angle is 14 mrad, which is just enough to provide en…
The potential of measurement of the relative statistical uncertainty of the ${σ(HZ)\times BR(H \rightarrow WW^{*})}$ decay, at the International Linear Collider (ILC) has been presented. The study is performed at the lowest energy stage of the proposed staged ILC, the 250 GeV stage. Monte Carlo samples representing all SM processes were passed through full detector simulation of the International Large Detector (ILD) model. Fully hadronic final state has been analyzed using an integrated luminosity of 500 fb$^{-1}$, using multivariate analysis technique. The obtained relative statistical uncer…
In this talk I summarize the physics case of the International Linear Collider (ILC) focusing on its potential towards discovery, discrimation or disentanglement of new physics beyond the Standard Model (BSM).
The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are the two options for a future high-energy, high-luminosity linear electron-positron collider. Both are expected to be built in stages, optimised for their physics potential. The main goals are the precision measurements of Higgs-boson and top-quark properties as well as direct and indirect searches for new physics Beyond Standard Model. In my talk I will review some of the latest results from both ILC and CLIC demonstrating their physics potential, pointing to similarities and complementarity of both projects.
This document discusses for the first time the experimental prospects on the measurement of cross section and the forward-backward asymmetry in $e^{-}e^{+}\rightarrow c\bar{c}$ collisions at 250 GeV at the International Linear Collider operating polarised beams. The cross section will be normalised to the total hadronic cross section. We discuss the results for an analysis assuming the integrated luminosity of 2000 fb$^{-1}$ foreseen in the baseline project. The measurement requires determining the charge of both jets identified as originated by a $c$-quark. The charge measurement is optimally…
We conducted a series of beam tests of prototype TPCs for the International Linear Collider (ILC) experiment, equipped with an MWPC, a MicroMEGAS, or GEMs as a readout device. The prototype operated successfully in a test beam at KEK under an axial magnetic field of up to 1 T. The analysis of data is now in progress and some of the preliminary results obtained with GEMs and MicroMEGAS are presented along with our interpretation. Also given is the extrapolation of the obtained spatial resolution to that of a large TPC expected for the central tracker of the ILC experiment.
We first outline the Standard Model (SM) of particle physics, particle production and decay, and the expected signal and background at a Higgs factory like the International Linear Collider (ILC). We then introduce high energy colliders and collider detectors, and briefly detail the ILC and the Silicon Detector (SiD), one of the two detectors proposed for the ILC. Next we review the available software tools for ILC event generation, SiD detector simulation, and event reconstruction. Finally we suggest open avenues in research for detector optimization and physics analysis. The pedagogical leve…
An updated study of measuring the W mass from a polarized threshold scan at ILC is presented with an emphasis on evaluating scan strategies that control experimental systematics. Highly longitudinally polarized beams of electrons and positrons such as are feasible at ILC offer significant advantages in terms of statistical power and in-situ control of background. Eventual experimental precision of around 2 MeV can be envisaged from this technique. Further work on both the accelerator design and theoretical uncertainties will likely be needed to take full advantage of this opportunity.
We describe DSiD, a fast simulation Delphes detector for the International Linear Collider (ILC) based on the full simulation performance of the SiD detector. SiD is one of two detectors described in the ILC Technical Design Report (TDR). The tracking efficiency, tracking momentum resolution, electromagnetic and hadronic calorimeter energy resolution, particle identification and flavor tagging efficiencies are taken from the Detailed Baseline Design (DBD) study as described in ILC TDR Volume 4: Detectors. In a cross-check study with $4 \times 10^6$ $e^+ e^- \rightarrow b \bar{b}$ events genera…
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.
The ILC Technical Design Report documents the design of a 500 GeV linear collider, but does not specify the center-of-mass energy steps of operation for the collider. The ILC Parameters Joint Working Group has studied possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes, and considered the evolution of the physics outcomes. These physics goals include Higgs precision measurements, top quark measurements and searches for new physics. We present an "optimized" operating scenario and the anticipate…
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.
We study the $e^+e^-\to h γ$ process at the International Linear Collider (ILC) to probe new physics in the $hγZ$ coupling. The study is performed at a center of mass energy of 250 GeV and is based on the full simulation of the International Large Detector (ILD). The expected signal significance is found to be 0.53 $σ$ for an integrated luminosity of 2000 fb$^{-1}$ in the case of the standard model. The corresponding 95 $\%$ confidence level upper limit for the signal cross section is 1.08 fb for left-handed beam polarization.
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 lepton in the coannihilation region relevant to dark matter, and heavy vector bosons coupling to the s-channel in e$^+$e$^-$ annihilation. The studies are based on the ILD concept a…
ILC (International Linear Collider) is under consideration as the next global project of particle physics. Its Technical Design Report, published in 2013, describes the accelerator for the center-of-mass energies above 200GeV. The operation of ILC at lower center-of-mass energies has not been studies intensively. This report discusses the operation of the ILC at a center-of-mass 91.2GeV and presents a possible parameter set.
This paper presents a full simulation study of the measurement of the production cross section ($σ_{\mathrm{ZH}}$) of the Higgsstrahlung process $\mathrm{e^{+}e^{-}\rightarrow ZH}$ and the Higgs boson mass ($M_{\mathrm{H}}$) at the International Linear Collider (ILC), using events in which a Higgs boson recoils against a Z boson decaying into a pair of muons or electrons. The analysis is carried out for three center-of-mass energies $\sqrt{s}$ = 250, 350, and 500 GeV, and two beam polarizations $\mathrm{e_{L}^{-}e_{R}^{+}}$ and $\mathrm{e_{R}^{-}e_{L}^{+}}$, for which the polarizations of $\ma…
The plan for the International Linear Collider (ILC) is now being prepared as a staged design, with the first stage of 2 ${\rm ab^{-1}}$ at 250GeV and later stages achieving the full project specifications with 4 ${\rm ab^{-1}}$ at 500 GeV. The talk presents the capabilities for precision Higgs boson measurements at 250 GeV. It is shown that the 250 GeV stage of the ILC will already provide many compelling results in Higgs physics, with new measurements unavailable at the Large Hadron Collider, model-independent determinations of key parameters, and possible discrimination of a variety of scen…
The plan for the International Linear Collider is now being prepared as a staged design, with the first stage at 250 GeV and later stages achieving the full project specifications with 4 ab-1 at 500 GeV. This talk will present the capabilities for precision Higgs boson measurements at 250 GeV and their relation to the full ILC program. It will show that the 250 GeV stage of ILC will already provide many compelling results in Higgs physics, with new measurements not available at LHC, model-independent determinations of key parameters, and tests for and possible discrimination of a variety of sc…
The ILC Technical Design Report documents the design for the construction of a linear collider which can be operated at energies up to 500 GeV. This report summarizes the outcome of a study of possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes. The evolution of the physics outcomes is emphasized, including running initially at 500 GeV, then at 350 GeV and 250 GeV. The running scenarios have been chosen to optimize the Higgs precision measurements and top physics while searching for evidence fo…
