Top-Quark Physics at the CLIC Electron-Positron Linear Collider
H. Abramowicz, N. Alipour Tehrani, D. Arominski, Y. Benhammou, M. Benoit, J. -J. Blaising, M. Boronat, O. Borysov, R. R. Bosley, I. Božović Jelisavčić, I. Boyko… 展开作者
H. Abramowicz, N. Alipour Tehrani, D. Arominski, Y. Benhammou, M. Benoit, J. -J. Blaising, M. Boronat, O. Borysov, R. R. Bosley, I. Božović Jelisavčić, I. Boyko, S. Brass, E. Brondolin, P. Bruckman de Renstrom, M. Buckland, P. N. Burrows, M. Chefdeville, S. Chekanov, T. Coates, D. Dannheim, M. Demarteau, H. Denizli, G. Durieux, G. Eigen, K. Elsener, E. Fullana, J. Fuster, M. Gabriel, F. Gaede, I. García, J. Goldstein, P. Gomis Lopez, C. Graf, S. Green, C. Grefe, C. Grojean, A. Hoang, D. Hynds, A. Joffe, J. Kalinowski, G. Kačarević, W. Kilian, N. van der Kolk, M. Krawczyk, M. Kucharczyk, E. Leogrande, T. Lesiak, A. Levy, I. Levy, L. Linssen, A. A. Maier, V. Makarenko, J. S. Marshall, V. Martin, V. Mateu, O. Matsedonskyi, J. Metcalfe, G. Milutinović Dumbelović, R. M. Münker, Yu. Nefedov, K. Nowak, A. Nürnberg, M. Pandurović, M. Perelló, E. Perez Codina, M. Petric, F. Pitters, T. Price, T. Quast, S. Redford, J. Repond, A. Robson, P. Roloff, E. Ros, K. Rozwadowska, A. Ruiz-Jimeno, A. Sailer, F. Salvatore, U. Schnoor, D. Schulte, A. Senol, G. Shelkov, E. Sicking, F. Simon, R. Simoniello, P. Sopicki, S. Spannagel, S. Stapnes, R. Ström, M. Szalay, M. A. Thomson, B. Turbiarz, O. Viazlo, M. Vicente, I. Vila, M. Vos, J. Vossebeld, M. F. Watson, N. K. Watson, M. A. Weber, H. Weerts, J. D. Wells, A. Widl, M. Williams, A. G. Winter, T. Wojtoń, A. Wulzer, B. Xu, L. Xia, T. You, A. F. Żarnecki, L. Zawiejski, C. Zhang, J. Zhang, Y. Zhang, Z. Zhang, A. Zhemchugov
The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies: 380 GeV, 1.5 TeV, and 3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of ttH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.
The Compact Linear Collider, CLIC, is a multi-TeV electron-positron collider proposed for construction at CERN. A detector model, CLICdet, that is suited for the experimental conditions at CLIC and is based on realistic performance, has been developed. This paper describes the implementation of CLICdet in a fast simulation tool for particle physics collider experiments, DELPHES. The geometry of the detector concept as well as performance parameters extracted from full simulation studies are implemented in DELPHES parameter cards for CLICdet. Jet reconstruction for electron-positron colliders i…
We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy $γγ$ collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a $γγ$ total (peak) luminosity of $2.0 (0.36) \times 10^{34}$ cm$^{-2}$s$^{-1}$ with $E_{CM}(γγ) \sim 115$ GeV. We show how CLICHE could be used to measure accurately the mass, $\bar…
The Compact Linear Collider, CLIC, is a proposed e$^+$e$^-$ collider at the TeV scale whose physics potential ranges from high-precision measurements to extensive direct sensitivity to physics beyond the Standard Model. This document summarises the physics potential of CLIC, obtained in detailed studies, many based on full simulation of the CLIC detector. CLIC covers one order of magnitude of centre-of-mass energies from 350 GeV to 3 TeV, giving access to large event samples for a variety of SM processes, many of them for the first time in e$^+$e$^-$ collisions or for the first time at all. Th…
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.
The event generator BEEC [Z. Yang, X.G. Wu and X.Y. Wang, Comput. Phys. Commun. 184, 2848 (2013)] was devoted to the simulation of heavy quarkonium production at an unpolarized electron-positron collider. We upgraded it here by adding the generation of quarkonium with polarized electron and positron beams. In addition, the production of color-singlet 2S-wave states were included. Several future electron-positron colliders with high luminosity have been under discussion in the past decade. Especially, their possibility of producing polarized beams is important for providing more insights into t…
We propose a new beam dump experiment at future colliders with electron ($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of $e^\pm$ beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at $e^+e^-$ linear collider) significantly enlarges the parameter region where the signal of the hidden particle can be discovered…
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon collisions. With the full integrated luminosity the Higgs boson photoproduction can be reliably observed. A large statistics of various quarkonium states can be collected. The LEP results on the photon structure function and the tau lepton anomalous magnetic moment can be improved by 1-2 orders of magnitude.
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.
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, t…
Universal extra dimensions and supersymmetry have rather similar experimental signatures at hadron colliders. The proper interpretation of an LHC discovery in either case may therefore require further data from a lepton collider. In this paper we identify methods for discriminating between the two scenarios at the linear collider. We study the processes of Kaluza-Klein muon pair production in universal extra dimensions in parallel to smuon pair production in supersymmetry, accounting for the effects of detector resolution, beam-beam interactions and accelerator induced backgrounds. We find tha…
The effect of single top production on the study of top quark pair production in future high energy electron--positron colliders is evaluated. The rate of the single top quark production process is sizeable throughout a large range of center-of-mass energies and cannot easily be distinguished from the dominant pair production process. We discuss the impact on the top quark mass extraction from a scan through the pair production threshold and the determination of top quark form factors in the continuum. These results advocate for the exploration of the inclusive $e^+e^-\rightarrow W^+bW^-\bar{b…
The generalized Crewther relation relates the cross section ratio $R=σ(e^+e^- \to {\rm hadrons})/σ(e^+e^- \to μ^+ μ^-)$ in $e^+e^-$ annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep inelastic scattering and provides a fundamental connection for observables in Quantum Chromodynamics (QCD) without scale or scheme ambiguities. The ratio $R$ can be measured at the upgrated Bejing Electron Positron Collider or the $τ$-Charm factory with higher precision and thus can be served for a high precision test of QCD in the Standard Model.
The physics potential of an e+e- linear collider can be significantly enhanced if both the electron and positron beams are polarised. Low energy running at the Z-resonance or close to the W-pair threshold is particularly attractive with polarised positrons. This note discusses the experimental aspects and physics opportunities of both low energy running and positron polarisation.
By exploiting the relatively long lifetime of the tau lepton, we propose several novel methods for searching for new physics at an electron-positron collider. We consider processes that involve final states consisting of a tau lepton pair plus two missing particles. The mass and spin of the new physics particles can be measured in 3-prong tau decays. The tau polarization, which reflects the coupling to new physics, can be measured from the $τ\to πν$ decay channel using the impact parameter distribution of the charged pion. We also discuss the corresponding backgrounds for these measurements, t…
Gamma-proton collisions allow unprecedented investigations of the low x and high $Q^{2}$ regions in quantum chromodynamics. In this paper, we investigate the luminosity for "ILC"$\times$LHC ($\sqrt{s_{ep}}=1.3$ TeV) and "CLIC"$\times$LHC ($\sqrt{s_{ep}}=1.45$ TeV) based $γp$ colliders. Also we determine the laser properties required for high conversion efficiency.
The potential for the measurement of the branching ratio of the Standard Model-like Higgs boson decay into a mu+mu- pair at 1.4 TeV CLIC is analysed. The study is performed using the fully simulated CLIC_ILD detector concept, taking into consideration all the relevant physics and the beam-induced backgrounds. Despite the very low branching ratio of the H->mu+mu- decay, we show that the product of the branching ratio times the Higgs production cross section can be measured with a statistical uncertainty of 38 percent, assuming an integrated luminosity of 1.5 ab^-1 collected in five years of the…
CLICdp, the CLIC detector and physics study, is an international collaboration presently composed of 23 institutions. The collaboration is addressing detector and physics issues for the future Compact Linear Collider (CLIC), a high-energy electron-positron accelerator which is one of the options for the next collider to be built at CERN. Precision physics under challenging beam and background conditions is the key theme for the CLIC detector studies. This leads to a number of cutting-edge R&D activities within CLICdp. The talk includes a brief introduction to CLIC, accelerator and detectors, h…
Precision studies at electron-positron colliders with center-of-mass energies in the charm-tau region and below have strongly contributed to our understanding of light-meson interactions at low energies. We focus on the processes involving two or three light mesons with invariant masses below nucleon-antinucleon threshold. A prominent role is given to the interactions of the nine lightest pseudoscalar mesons (pions, kaons, $η$, and $η'$) and the two narrow neutral isoscalar vector mesons $ω$ and $ϕ$. Experimental methods used to produce the mesons are reviewed as well as theory tools to extrac…
The Compact Linear Collider (CLIC) is a proposed TeV-scale high-luminosity electron-positron collider. For an optimal exploitation of its physics potential, CLIC is foreseen to be built and operated in three stages, with centre-of-mass energies ranging from 380 GeV up to 3 TeV. Electron beam polarisation is provided at all energies. The initial energy stage will focus on precision measurements of Higgs-boson and top-quark properties. The subsequent energy stages enhance the reach of many direct and indirect searches for new physics Beyond the Standard Model (BSM) and give access to the Higgs s…
In 2012, a light scalar boson (denoted as H(125) in this paper) was discovered at the LHC. We explore the possible correlation between the lightness of H(125) and the smallness of CP-violation based on the Lee model, namely the spontaneous CP-violation two-Higgs-doublet-model. It is a new way to understand why H(125) is light. Based on this we propose that it is the much heavier scalar bosons, instead of the H(125), which need to be understood. This opens a new paradigm that one tries to understand the electro-weak symmetry breaking and CP violation. For the new paradigm, similar to many other…
A precise knowledge of charged Triple Gauge Couplings (cTGCs) is important for the determination of Higgs couplings and for constraining physics beyond the Standard Model. Future high-energy $e^{+}e^{-}$ colliders could have a significantly improved sensitivity to anomalous cTGCs. The fit framework presented here extracts cTGCs in parallel with chiral cross sections and beam polarisation parameters. It demonstrates that cTGCs can be measured with precision in the $10^{-3}-10^{-4}$ range. A strong dependence of the cTGC sensitivity on the available luminosities and polarisations is observed.
The Compact Linear Collider (CLIC) is a proposed high-luminosity collider that would collide electrons with their antiparticles, positrons, at energies ranging from a few hundred Giga-electronvolts (GeV) to a few Tera-electronvolts (TeV). By covering a large energy range and by ultimately reaching multi-TeV $e^+e^-$ collisions, scientists at CLIC aim to improve the understanding of nature's fundamental building blocks and to discover new particles or other physics phenomena. CLIC is an international project with institutes world-wide participating in the accelerator, detector and physics studi…
We investigate the prospect of discovering the Inert Doublet Model scalars at CLIC. As signal processes, we consider the pair-production of inert scalars, namely e+e- -> H+H- and e+e- -> AH, followed by decays of charged scalars H+ and neutral scalars A into leptonic final states and missing transverse energy. We focus on signal signatures with two muons or an electron and a muon pair in the final state. A number of selected benchmark scenarios that cover the range of possible collider signatures of the IDM are considered. For the suppression of SM background with the same visible signature, m…
The virtual production of axion-like particles (ALPs) in the light-by-light scattering at the CLIC collider is studied. Both differential and total cross sections are calculated, assuming interaction of the ALP with photons via CP-odd term in the Lagrangian. The 95\% C.L. exclusion regions for the ALP mass and its coupling constant are given. By comparing our results with existing collider bounds, we see that the ALP search at the CLIC has a great physics potential of searching for the ALPs, especially, in the mass region 1 TeV -- 2.4 TeV, with the collision energy $\sqrt{s} = 3000$ GeV and in…
Jet flavour identification in multi-TeV e+e- collisions is expected to provide insights on new phenomena at scales beyond those probed by the LHC. The anticipated high track density and jet collimation represent a new challenge to jet tagging algorithms. A method, based on the sampling of the jet charged multiplicity, sensitive to the long decay length and large decay multiplicity of heavy flavour hadrons is proposed and the expected performances for the tagging of e+e- -> bb events at 3 TeV are discussed.
We study the $W^+W^-γ(Z)$ productions at both the CERN Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) in the framework of the Randall-Sundrum (RS) model. The impacts of the virtual RS Kaluza-Klein (KK) graviton on these processes are studied and compared with the standard model (SM) background. We present the integrated and differential cross sections in both the RS model and the SM. The results show that the relative RS discrepancies at the CLIC differ from those at the LHC, particularly in the transverse momentum and rapidity distributions. We also find that the RS signat…
Probing Higgs width $Γ_h$ is critical to test the Higgs properties. In this work we propose to measure $Γ_h$ at the $e^+e^-$ collider with a model-independent analysis under the Standard Model Effective Field Theory framework. We demonstrate that making use of the cross section measurements from $e^+e^-\to Zh$, $e^+e^-\to ν_e\barν_eh$ production and Higgs decay branching ratios $h\to WW^*/ZZ^*/γγ$, one could determine $Γ_h$ at a percentage level with a center of mass energy $\sqrt{s}=250$ and 350 GeV and integrated luminosity $5~{\rm ab}^{-1}$. This conclusion would not depend on the assumptio…
In the context of the positrons sources studies for the Future Linear Collider, the Accelerator Department at LAL Orsay is involved since several years in different activities both experiments and simulations.
One of the most attractive features of a linear collider is the ability to extend its energy reach in stages, and to adapt the running plan flexibly in terms of maximum centre-of-mass energy and time spent at each stage. The baseline luminosity staging scenario for CLIC is well-established, and has been used to obtain sensitivity projections for Standard Model measurements and Beyond Standard Model scenarios. Here, as an exercise to illustrate what could be obtained from an alternative running scenario, Higgs coupling sensitivities are presented for the case where more data is collected at the…
We present a study to examine the sensitivity of a future $e^{-} e^{+}$ collider to the anomalous top flavour-changing neutral current (FCNC) to the gluon. To separate signal from background a multivariate analysis is performed on top-quark pair and background events, where one top quark is considered to follow the dominant Standard Model (SM) decay, $t \rightarrow Wb$, and the other top decays through FCNC, $t\rightarrow qg$, where $q$ is a $u-$ or a $c-$quark. The analysis of fully-hadronic FCNC decay of the $t \bar{t}$ pair is also presented. The $95\%$ confidence level limits on the top-qu…
The Compact Linear Collider (CLIC) is a future electron-positron collider that will allow measurement of the trilinear Higgs self-coupling in double Higgs boson events produced at its high-energy stages with collision energies of $\sqrt{s}$ = 1.5 and 3 TeV. The sensitivity to the Higgs self-coupling is driven by the measurements of the cross section and the invariant mass distribution of the Higgs-boson pair in the W-boson fusion process, e$^+$e$^-\to$HH$ν_e \barν_e$. It is enhanced by including the cross-section measurement of ZHH production at 1.5 TeV. The expected sensitivity of CLIC for Hi…
In this lecture, the physics potential for the e+e- linear collider experiments ILC and CLIC is reviewed. The experimental conditions are compared to those at hadron colliders and their intrinsic value for precision experiments, complementary to the hadron colliders, is discussed. The detector concepts for ILC and CLIC are outlined in their most important aspects related to the precision physics. Highlights from the physics program and from the benchmark studies are given. It is shown that linear colliders are a promising tool, complementing the LHC in essential ways to test the Standard Model…
The Inert Doublet Model (IDM) is a simple extension of the Standard Model, introducing an additional Higgs doublet that brings in four new scalar particles. The lightest of the IDM scalars is stable and is a good candidate for a dark matter particle. The potential of discovering the IDM scalars in the experiment at the Compact Linear Collider (CLIC), an e$^{+}$e$^{-}$ collider proposed as the next generation infrastructure at CERN, has been tested for two high-energy running stages, at 1.5 TeV and 3 TeV centre-of-mass energy. The CLIC sensitivity to pair-production of the charged IDM scalars w…
The Compact Linear Collider CLIC is an option for a future multi-TeV electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The CLIC physics potential for measurements of the 125 GeV Higgs boson has been studied using full detector simulations for several centre-of-mass energies. The presented results provide crucial input to the energy staging strategy for the CLIC accelerator. The complete physics program for measurements of accessible Higgs boson couplings is presented in this contribution. The u…
The addition of $SU(2)_L$ triplet fermions of zero hypercharge with the Standard Model (SM) helps to explain the origin of the neutrino mass by the so-called seesaw mechanism. Such a scenario is commonly know as the type-III seesaw model. After the electroweak symmetry breaking the mixings between the light and heavy mass eigenstates of the neutral leptons are developed which play important roles in the study of the charged and neutral multiplets of the triplet fermions at the colliders. In this article we study such interactions to produce these multiplets of the triplet fermion at the electr…
The violation of CP symmetry at the electro-weak scale is one of the essential ingredients for electro-weak baryogenesis. It is therefore of great interest to map the CP properties of the Higgs sector in as much detail as possible. A linear electron-positron Higgs factory collider will provide many opportunities to probe the CP nature of the Higgs sector, thanks to access to several Higgs production processes at a wide range of centre-of-mass energies. In this paper we report on two studies based on full simulation of detector response and realistic reconstruction algorithms: 1) a study of $h …
The Compact Linear Collider (CLIC) is a mature option for a future electron-positron collider operating at centre-of-mass energies of up to 3 TeV. It incorporates a novel two-beam acceleration technique offering accelerating gradient of up to 100 MeV/m. CLIC would be built and operated in a staged approach with three centre-of-mass energy stages currently assumed to be 380 GeV, 1.5 TeV, and 3 TeV. The first CLIC stage will be focused on precision Higgs and top quark measurements. The so called "Higgs-strahlung" process ($e^+ e^- \to \mathrm{ZH}$) is a key for a model independent measurement of…
Circular electron positron colliders, such as the CEPC and FCC-ee, have been proposed to measure Higgs boson properties precisely, test the Standard Model, search for physics beyond the Standard Model, and so on. One of the important goals of these colliders is to measure the $W$ boson mass with great precision by taking data around the $W$-pair production threshold. In this paper, the data-taking scheme is investigated to maximize the achievable precisions of the $W$ boson mass and width with a threshold scan, when various systematic uncertainties are taken into account. The study shows that …
Conformal tracking is an innovative track finding strategy adopted for the detector at the Compact Linear Collider (CLIC), a proposed future electron-positron collider. It features a pattern recognition in a conformal-mapped plane using the cellular automaton algorithm to reconstruct the trajectory of charged particles in a magnetic field. The efficiency and robustness of the algorithm are validated using full-simulation studies in the challenging beam-induced background conditions expected for the 3 TeV stage of the CLIC collider. The tracking performance requirements, set by the ambitious CL…
The future Compact Linear Collider (CLIC) offers a possibility for a rich precision physics programme, in particular in the Higgs sector through the energy staging. This is the first paper addressing the measurement of the Standard Model Higgs boson decay into two muons at 1.4 TeV CLIC. With respect to similar studies at future linear colliders, this paper includes several novel contributions to the statistical uncertainty of the measurement. The later includes the Equivalent Photon Approximation and realistic forward electron tagging based on energy deposition maps in the forward calorimeters…
We propose a fixed-target experiment to search for Axion-like particles (ALPs) coupling to photons, which utilizes electron and positron beams available at KEK Linac. The sensitivity to ALP is evaluated for two shielding setups in conjunction with other beam dump experiments, fixed-target experiments, and $e^+e^-$ collider experiments. This study shows that the two setups can explore the gap between the search region excluded by the beam dump experiments and the $e^+e^-$ collider experiments.
I summarise the physics opportunities and experimental challenges at future Linear Colliders, using material from the recent ECFA/DESY workshop on the subject as well as contributions to the series of worldwide studies. For reasons of economy, the discussion is restricted to the European Tesla project and to its electron-positron mode only.
An electron-positron linear collider in the energy range between 500 and 1000 GeV is of crucial importance to precisely test the Standard Model and to explore the physics beyond it. The physics program is complementary to that of the Large Hadron Collider. Some of the main physics goals and the expected accuracies of the anticipated measurements at such a linear collider are discussed. A short review of the different collider designs presently under study is given including possible upgrade paths to the multi-TeV region. Finally a framework is presented within which the realisation of such a p…
The harsh machine background at the Compact Linear Collider (CLIC) forms a strong constraint on the design of the innermost part of the tracker. For the CLIC Conceptual Design Report, the detector concepts developed for the International Linear Collider (ILC) were adapted to the CLIC environment. We present the new layout for the Vertex Detector and the Forward Tracking Disks of the CLIC detector concepts, as well as the background levels in these detectors. We also study the dependence of the background rates on technology parameters like thickness of the active layer and detection threshold.
Particle Identification (PID) plays a key role in heavy flavor physics in high-energy physics experiments. However, its impact on Higgs physics is still not clear. In this note, we will explore some of the potential of PID to improve the identification of heavy-flavour jets by using identified charged Kaons in addition to the traditional vertexing information. This could result in a better measurment of the Higgs-charm Yukawa coupling at the future $e^+e^-$ colliders.
This report describes an all-solid state central tracker which is intended for use in a detector at the proposed DESY 500 GeV electron-positron linear collider or a similar accelerator. The precise position measurements from position-sensitive silicon detectors give the tracker an outstanding momentum resolution for high momentum tracks: sigma_p/p^2 = 3.6 x 10^{-5} (GeV/c)^{-1} for tracks perpendicular to the beam-line. The report concludes with an example layout for a detector which uses this central tracker.
We investigate the scenario where the dark matter only interacts with the charged leptons in the standard model via a neutral vector mediator $Z'$. Such a scenario with a 430 GeV dark matter can fit the recent positron fluxes observed by the AMS-02 Collaborations, with the reasonable boost factors. We study the possibility of searching such leptophilic $Z'$ via its lepton final states and invisible decay modes at the future electron-positron colliders, such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). We find that for the benchmark models with $Z'$ mass fr…
The Compact Linear Collider (CLIC) is a proposed high-luminosity linear electron-positron collider at the energy frontier. It is foreseen to be built and operated in three stages, with a centre-of-mass energy ranging from a few hundred GeV up to 3 TeV. The main beam-induced background impacting CLIC physics analyses is produced by beamstrahlung radiation from the electron and positron bunches traversing the high field of the opposite beam and converting to hadrons. The timing selections are a powerful tool to discriminate signal from background events at CLIC. For each CLIC stage, three sets o…
This exposition provides a detailed picture of ongoing and planned activities towards the development of a detector for a high-energy Linear Collider. Cases for which research and development activity does not exist, or needs to be bolstered, are identified for the various subsystems. The case is made that the full exploitation of the potential of a high-energy Linear Collider will require the augmentation of existing detector technology and simulation capability, and that this program should become a major focus of the worldwide particle physics community should the construction of a Linear C…
The study of the process $e^+e^- \to W^+W^-$ at Linear Collider energies presents a good opportunity to investigate anomalous triple gauge boson couplings and $W^+_LW^-_L$ rescattering. The helicity analysis of the $e^+e^- \to W^+_LW^-_L$ decays will benefit if the charm quark containing jet can be identified for events which contain one hadronic $W$ boson decay to a charm and another quark. A JAVA implementation of the SLD collaboration's topological vertex finding algorithm (ZVTOP) in the linear collider analysis framework has been used to extract charm tag efficiencies and purities based on…
After the Higgs discovery, precise measurements of the Higgs properties and the electroweak observables become vital for the experimental particle physics. A powerful Higgs/Z factory, the Circular Electron Positron Collider(CEPC) is proposed. The Particle Flow oriented detector design is proposed to the CEPC and a Particle Flow algorithm, Arbor is optimized accordingly. We summarize the physics object reconstruction performance of the Particle Flow oriented detector design with Arbor algorithm and conclude that this combination fulfills the physics requirement of CEPC.
TPC is a promising technology for the future electron positron colliders. However, its application might be limited at high event rate and high hit occupancies. In this paper, we study the feasibility of using TPC at the circular electron positron collider (CEPC) at $Z$ pole using full simulated $Z \rightarrow q\bar{q}$ samples. By evaluating the local charge density and voxel occupancy at different TPC parameters. Our study shows that the TPC could be applied to the CEPC $Z$ pole operation if back flow ion is controlled to per mille level. We also suggest the applicable TPC parameters for FCC…
We discuss a low energy $e^+e^-$ collider for production of the not yet observed ($μ^+μ^-$) bound system (dimuonium). Collider with large crossing angle for $e^+e^-$ beams intersection produces dimuonium with non-zero momentum, therefore, its decay point is shifted from the beam collision area providing effective suppression of the elastic $e^+e^-$ scattering background. The experimental constraints define subsequent collider specifications. We show preliminary layout of the accelerator and obtained main parameters. High luminosity in chosen beam energy range allows to study $π^\pm$ and $η$ -m…
