Conveners
Lepton Colliders
- Yu Gao (Institute of High Energy Physics of the Chinese Academy of Sciences)
Lepton Colliders
- Yu Gao (Institute of High Energy Physics of the Chinese Academy of Sciences)
Lepton Colliders
- Kechen Wang (Wuhan University of Technology)
Lepton Colliders
- Gauthier Durieux (CERN)
Lepton Colliders
- Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))
Lepton Colliders
- Kechen Wang (Wuhan University of Technology)
Lepton Colliders
- Kechen Wang (Wuhan University of Technology)
Lepton Colliders
- Gauthier Durieux (CERN)
Lepton Colliders
- Yu Gao (Institute of High Energy Physics of the Chinese Academy of Sciences)
Lepton Colliders
- Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))
The Circular Electron Positron Collider is designed to deliver 1 M Higgs boson, 100 M W boson, 1 Tera Z boson in roughly 10 years of data taking. It is not only a machine for precision measurement but also a Discovery machine. To quantify its physics potential and comparative advantages compared to other facilities, intensive physics studies have been performed, aiming at CEPC physics white...
The discovery of the Higgs boson marked the beginning of a new era in HEP. Precision measurement of the Higgs boson properties and exploring new physics beyond the Standard Model using Higgs as a tool become a natural next step beyond the LHC. Among the proposed Higgs factories worldwide, the Circular Electron Positron Collider (CEPC) is proposed by the Chinese HEP community and to be hosted...
After the recent update of the European Strategy an International Muon Collider Collaboration is forming. The talk will give an overview of the project and the plans of the collaboration. It will highlight some of the challenges and the technologies to address them.
The talk will summarise the status of the muon collider physics potential assessment
The diphoton channel at lepton colliders, $e^+e^- (\mu^+\mu^-) \to \gamma \gamma$, has a remarkable feature that the leading new physics contribution comes only from dimension-eight operators. This contribution is subject to a set of positivity bounds, derived from fundamental principles of Quantum Field Theory, such as unitarity, locality, analyticity and Lorentz invariance. These...
We consider the positivity bounds on dimension-8 four-electron operators and study two related phenomenological aspects at future lepton colliders. First, if positivity is violated, probing such violations will revolutionize our understanding of the fundamental pillars of quantum field theory and the S-matrix theory. Second, the positive nature of the dimension-8 parameter space allows us to...
The talk will address the potential of the muon collider to probe Supersymmetry and related ideas for physics Beyond the Standard Model.
The proposed Circular Electron Positron Collider (CEPC) with a center-of-mass energy √ s = 240 GeV will serve as a Higgs factory, while it can offer good opportunity for new physics search at low energy, which is challenging in hadron colliders but motivated by some theory models such as dark matter. This talk will cover electroweak SUSY and slepton search prospects at CEPC.
We study the impact of future electron-positron colliders, such as CEPC, ILC and FCC-$ee$, on global fits of the simplest supersymmetric models, such as the CMSSM and pMSSM-7, using GAMBIT and publicly available data published by the GAMBIT Community. From the impact of the additional likelihoods, we discuss the discovery prospects and reaches of future colliders.
Future lepton colliders such as the Circular Electron Positron Collider (CEPC) and FCC (Future Circular Collider)-ee would run as high-luminosity $Z$-boson factories, which offer a unique opportunity to study long-lived particles which couple to $Z$-bosons. We consider the long-lived lightest neutralinos in the R-parity-violating supersymmetry, produced from $Z$-boson decays, and show the...
Precision measurements and searches for new phenomena in the Higgs sector are among the most important goals in particle physics. Experiments at the Future Circular Colliders (FCC) are ideal to study these questions. Electron-positron collisions (FCC-ee) up to an energy of 365 GeV provide the ultimate precision with studies of Higgs boson couplings, mass, total width, and CP parameters, as...
As Higgs factory, Higgs study is one of the main physics goal at the CEPC. This presentation will present the latest Higgs results at CDR and new updates afterwards. In addition, the impact of 360 GeV run on CEPC Higgs physics will be addressed as well. Finally, some comparison with other colliders on physics will be discussed.
We propose a method to improve the efficiency of preselection in Higgs signal searches at CEPC.
For this propose we developed three machine learning algorithms including boosted decision tree algorithm, fully-connected neural networks and convolutional neural networks.
Among all these algorithms, we found the fully-connected neural networks gives the best prediction on Higgs signals....
I discuss the physics that underpins QED collinear-factorisation formulae, in particular the PDFs, and some applications of the latter to the simulation of e+e- collision processes
After the triumph of discovering the Higgs boson at the CERN Large Hadron Collider, people are getting increasingly interested in studying the Higgs properties in detail and searching for the physics beyond the Standard Model (SM). A multi-TeV lepton collider provides a clean experimental environment for both the Higgs precision measurements and the discovery of new particles. In high-energy...
Studying the properties of Standard Model (SM) – like Higgs boson becomes one important window to explore the physics beyond the SM. In this work, we present studies about the implications of the Higgs and Z-pole precision measurements at future Higgs Factories. We perform a global fit to various Higgs search channels to obtain the 95% C.L. constraints on the model parameter spaces of Two...
We study the discovery potential of the non-Standard Model (SM) heavy Higgs bosons in theTwo-Higgs-Doublet Models (2HDMs) at a multi-TeV muon collider and explore the discrimination power among different types of 2HDMs.
We study the complementarity of the proposed multi-TeV muon colliders and the near-future gravitational wave (GW) detectors to the first order electroweak phase transition (FOEWPT), taking the real scalar extended Standard Model as the representative model. A detailed collider simulation shows the FOEWPT parameter space can be greatly probed via the the vector boson fusion production of the...
The search for new physics with very feeble interaction strength is stimulating a vibrant experimental program. This talk will present the opportunities that could be exploited at a future high-energy muon collider and highlight the experimental challenges arising from this specific collision environment. Finally, recent results studying the reach of such machine in models predicting...
The International Linear Collider offers a number of unique opportunities for searches for dark matter and dark sector particles potentially related to realization of supersymmetry in Nature. The collider program will offer important capabilities, but also, the ILC will enable new fixed-target experiments using the high-energy electron and positron beams, both beam dump experiments and...
We consider a scenario where light bino is the next-to-lightest supersymmetric particle (NLSP) and gravitino/axino is the lightest superysmmetric particle (LSP). For a bino mass less than or around hundred GeV, it can be pair produced at the future lepton colliders through t−channel slepton exchange, subsequently decaying into a gravitino/axino plus a photon. We study the prospects to look for...
An electron-positron Higgs factory is regarded as the highest-priority next large-scale collider facility. Among others, two linear collider projects are being considered: the Compact Linear Collider (CLIC) and the International Linear Collider (ILC). Reaching energies at the TeV scale, both machines would allow us not only to study Higgs boson and top quark properties with very high precision...
The Future Circular Collider with electron-positron beams (FCC-ee) should provide improvements of the electroweak precision measurement concerning Z, W, H, and their masses by a large factor over the present status. The unparalleled experimental precision would open, via Electroweak loop corrections, a broad discovery potential for new, at least weakly interacting particles up to high energy...
Measuring longitudinally polarized vector boson scattering in, e.g., the ZZ channel is a promising way to investigate the unitarization scheme from the Higgs and possible new physics beyond the Standard Model. However, at the LHC, it demands the end of the HL-LHC lifetime luminosity, 3000/fb, and advanced data analysis technique to reach the discovery threshold due to its small production...
An open question in particle physics is whether the Higgs mechanism generates the masses of all the fermions by the Yukawa interactions. We propose to scrutinize the muon Yukawa coupling at a high-energy muon collider. By the subtle interplay between the muon Yukawa coupling in the high-energy production of multiple (vector and Higgs) bosons, we show that it is possible to measure the muon...
The minimal $U(1)_X$ extension of the Standard Model (SM) is a well-motivated new physics scenario, where the anomaly cancellation requirement dictates the new neutral gauge boson ($Z^\prime$) couplings with the SM fermions in terms of two scalar charges ($x_H$ and $x_\Phi$). In this paper, we investigate the SM charged fermion pair production mechanism for different values of these scalar...
We propose to search for millicharged particles in electron colliders operated with the center-of-mass energies at ${\cal O}$(1-10) GeV, which include Belle II, BESIII, BaBar, and also the proposed experiment STCF. We use the monophoton final state to probe the parameter space of millicharged particles at electron colliders. We find that electron colliders have sensitivity to the previously...
Radiation Amplitude Zero (RAZ) is a well-known phenomenon in electroweak sector [1]. The tree-level single photon amplitudes for various electroweak processes vanish at certain regions of phase space depending on the electric charges and four-momenta of the external particles [2]. Using this fact we perform PYTHIA based analyses to probe the signature of leptoquarks [3], which have gained...
Z-pole operation at FCC-ee offers a unique laboratory for flavor physics, with the anticipated production of 10^12 b-quarks and the opportunity for triggerless data-taking in a clean e+e- collision environment. Using new simulation and analysis tools developed for FCC-ee physics and performance studies, theoretically compelling beauty, charm, and tau decay modes are studied in order to...
We proposed a novel method to test the CP-violation in scalar sector at Higgs factories. Based on the CP-properties' analysis, if we have already discovered two scalars, the existence of three vertices $H_1ZZ$, $H_2ZZ$, and $H_1H_2Z$ at tree level becomes the evidence for us to confirm CP-violation. At a lepton collider, all four components of energy-momentum can be reconstructed, and thus all...
We will discuss the experimental challenges and prospects for precision measurements of observables associated to quark pair production at e+e- Higgs/Top Factories (with focus in the ILC)
In gauge-Higgs unification (GHU), the 4D Higgs boson appears as a part of the fifth dimensional component of 5D gauge field. Recently, an $SO(11)$ GUT inspired $SO(5)\times U(1)\times SU(3)$ GHU model has been proposed. In the GHU, Kaluza-Klein (KK) excited states of neutral vector bosons, photon, $Z$ boson and $Z_R$ boson, appear as neutral massive vector bosons $Z'$s. The $Z'$ bosons in the...
