The Cool Copper Collider (C$^3$) is a proposed linear electron-positron linear collider operating at a center-of-mass energy of 250 GeV, with an upgrade to 550 GeV. A key aspect of evaluating the physics potential of any proposed Higgs factory is to quantify the effect of the various beam- and machine-induced backgrounds on the detector occupancy, and, ultimately, on the expected precision...
New physics models such as Z' models or EWIMPs (via loop contribution) can be probed by the precise measurements of 2-fermion final states at Higgs factories and measuring dependence on fermions, polarization and angles can enhance the possibility of searching and identifying those models. We are studying qq and ll final states with 500 GeV ILC using ILD full simulation. The analysis methods...
Scalars particles lighter than 90 GeV are predicted in various new physics scenarios. They can be produced via rare decays of the Z boson, together with a photon, offering an ideal discovery channel in e+e- colliders. I will present possible search strategies at the Tera-Z run of the FCC-ee, highlighting the complementarity with other colliders (HL-LHC) and the high-energy reach of such...
While the ionization process by charged particles (dE/dx) is commonly used for particle identification, uncertainties in total energy deposition limit particle separation capabilities. To overcome this limitation, the cluster counting technique (dN/dx) leverages the Poisson nature of primary ionization, providing a statistically robust method for inferring mass information. Simulation studies...
The future lepton collider experiments, e.g. the Circular Electron Positron Collider (CEPC), are aimed at the precise measurement of the Standard Model (SM) particles and the exploration of new physics. This imposes stringent requirement on the jet measurement. Therefore, a novel high granularity calorimetry system has been proposed. It contains a homogeneous crystal bar electromagnetic...
Future e$^+$e$^-$ colliders, thanks to their clean environment and triggerless operation, offer a unique opportunity to search for long-lived particles (LLPs) at sub-TeV energies. Considered in this contribution are promissing prospects for LLP searches offered by the International Large Detector (ILD), with a Time Projection Chamber (TPC) as the core of its tracking systems, providing almost...
Future Higgs Factories will allow the precise study of $e^{+}e^{-}\rightarrow q\bar{q}$ with 𝑞$q=s,c,b,t$ interactions at different energies, from the Z-pole to high energies never reached before.
In this contribution, we will discuss the experimental prospects for the measurement of differential observables in $e^{+}e^{-}\rightarrow b\bar{b}$ and $e^{+}e^{-}\rightarrow c\bar{c}$ processes at...
Calorimetry based on liquefied noble gases is a well proven technology that has been successfully applied in numerous high-energy physics experiments, such as DØ at the Tevatron, ATLAS at the LHC and NA62 at the SPS. In addition to extreme radiation hardness, noble liquid calorimeters provide excellent energy resolution, linearity, stability, uniformity and timing properties at a reasonable...
We discuss the evidence for a Higgs boson with a mass of $\sim$ 95.4 GeV. We demonstrate the physics capabilities of a 250 GeV $e^+e^-$ collider in the analysis of such a light Higgs boson, making it the best physics case for such a future experiment
Any new physics (NP) lying at the TeV scale must pass stringent flavor as well as collider bounds. Since the top Yukawa gives the largest quantum correction to the Higgs mass, one well-motivated expectation is TeV-scale NP dominantly coupled to the third family. This setup delivers U(2) flavor symmetries that allow one to start explaining flavor at the TeV scale, while simultaneously improving...
Detector studies for future experiments rely on advanced software tools to estimate performance and optimize their design and technology choices. The Key4hep project provides a turnkey solution for the full experiment life- cycle based on established community tools. An important ingredient for the performance of future Higgs Factory experiments, is the particle flow reconstruction for optimal...
The technology of dual readout calorimetry, based on the simultaneous measurement of Cherenkov and scintillation light shows great potential for applications at Future Colliders.
Coupled with high-granularity designs, it allows to obtain excellent energy resolution for e.m. particles, and at the same time an event-by-event compensation of the electromagnetic and hadronic energy...
The physics program of the Higgs factory will focus on measurements of the 125 GeV Higgs boson, with the Higgs-strahlung process being the dominant production channel at 250 GeV. However, production of extra light scalars is still not excluded by the existing experimental data, provided their coupling to the gauge bosons is sufficiently suppressed. Fermion couplings of such a scalar could also...
In this talk, we assess the FCC-ee reach for $Z/h\to bs, cu$ decays as a function of jet tagging performance. Recent advances in $b$, $c$, and $s$ quark tagging coupled with novel statistical analysis techniques allow the FCC-ee to place phenomenologically relevant bounds on flavor violating Higgs and $Z$ decays to quarks. We also update the SM predictions for the corresponding branching...
The challenges expected for the future $e^+e^-$ colliders era are pushing to re-think the HEP computing models at many levels.
The evolution toward solutions that allow an effortless interactive analysis experience is one of the key topics foreseen by future colliders collaborations.
In this context, EDM4HEP offers a high-level model which makes it a flexible and user-friendly tool for...
To study the physics potential of the detector concepts proposed for FCC-ee, a detailed simulation of detectors responses to visible particles is required. An essential component of the simulation process is the description of the detector components in terms of geometry, materials and sensitive parts. The future collider community agreed on using the DD4hep framework for their detector...
Technologically mature accelerator and detector design and a well-understood physics program make the ILC a realistic option for the realization of a future Higgs factory. Energy staged data collection, employment of beam polarization, and capability to reach a TeV center-of-mass energy, enable unique sensitivity to New Physics deviations from the Standard Model predictions in the Higgs sector...
A discovery of Lepton Number Violating (LNV) processes at future colliders would be a fascinating signature of new physics beyond the Standard Model (SM). It would prove that the light neutrinos have Majorana-type masses, and could allow a deep insight into the neutrino mass generation mechanism. We discuss how observable LNV can originate from collider testable low scale type I neutrino mass...
Progress on topics related to understanding the potential for precision measurements of the W mass will be reported building on previous work. This includes recent work on WW event selection issues relevant to continuum and threshold, further work on assessing the performance of lepton-based W mass estimators, and developments associated with constrained kinematic fits.
Type I seesaw models generating small masses for the observed neutrinos predict not only heavy neutrinos but also the presence of lepton number violating (LNV) processes. After the discovery of these heavy neutrinos, it becomes essential to examine the amount of LNV in order to shed light on the corresponding neutrino mass-generating mechanism. We discuss the potential of future lepton...
Recently, a concept for a Hybrid Asymmetric Linear Higgs Factory (HALHF) has been proposed, where a center-of-mass energy of 250 GeV is reached by colliding a plasma-wakefield accelerated electron beam of 500 GeV with a conventionally accelerated positron beam of about 30 GeV. While clearly facing R&D challenges, this concept bears the potential to be significantly cheaper than any other...
The reconstruction of heavy flavour jets will play an important role at future e+e- Higgs factories: $H\to b\bar{b}$ is the most frequent decay mode of the SM Higgs, and $H\to c\bar{c}$ is particularly challenging to measure at the LHC. Also exotic scalars could decay into these modes, and b- and/or c-jets occur frequently in top quark as well as Z and W boson decays. While the reconstruction...
The majority of Monte-Carlo (MC) simulation campaigns for future Higgs factories has so far been based on the leading-order (LO) matrix elements provided by Whizard 1.95, followed by parton shower and hadronization in Pythia6, using the tune of the OPAL experiment at LEP. In this contribution, we test the next-to-leading-order (NLO) mode of Whizard. NLO events of key processes ($e^+e^-\to...
Neutrinos are the most elusive particles known. Heavier sterile neutrinos mixing with the Standard Model partners might solve the mystery of the baryon asymmetry of the universe and take part in the mass generation mechanism for the light neutrinos. Future lepton colliders, including e+e− Higgs factories, as well as multi-TeV electron and muon machines, will provide the farthest search reach...
The Cool Copper Collider (C^3) is a proposed linear electron-positron linear collider operating at a center-of-mass energy of 250 GeV, upgradable to 550 GeV. A key aspect of evaluating the physics potential of any proposed Higgs factory is to quantify the effect of the various beam- and machine-induced backgrounds on the detector occupancy, and, ultimately, on the expected precision reach. In...
At all center-of-mass energies of a future high-energy e$^{+}$e$^{-}$ collider precise determination of the absolute integrated luminosity underpins the physics program. It is especially critical for measuring the number of light neutrino generations ($N_{\nu}$). In this contribution we will emphasize the prospects and investigate the potential of using the pure QED process,...
Along the path defined by the European Strategy for Particle Physics, an electron-positron Higgs factory is the highest priority next collider.
The FCC program at CERN combine in the same 100km infrastructure a high luminosity Higgs and Electroweak factory e collider, followed by a 100 TeV hadron collider. The IDEA project (Innovative Detector for an Electron–positron Accelerator), as a...
The differential and total cross section or related observables of difermion production in high e+e- collisions bear a considerable potential for the discovery of the onset of new physics as the centre-of-mass energy increases. Most of these measurements are only possible due to beam polarisation. Earlier measurements have reported on the determination of the differential cross sections of b,...
The IDEA drift chamber is designed to provide efficient tracking, a high-precision momentum measurement and excellent particle identification by exploiting the application of the cluster counting technique. To investigate the potential of the cluster counting techniques on physics events, a simulation of the ionization cluster generation is needed, therefore we developed algorithms that can...
In this talk we explore the interpretation of neutrino masses as radiatively generated, leveraging the forthcoming precision at the Future Circular Collider. We highlight the discernibility of Higgs-strahlung signals and radiative corrections as key tools for revealing New Physics. In particular, we consider the role of extra fermions in altering the signature proper of the Inert Doublet...
The IDEA experiment muon systems (pre-shower and external tracking) require a large number of u-RWELL detectors. To keep the cost of the entire system affordable, an optimization of the readout electronics channel is needed. For this purpose, resolution studies as a function of the readout segmentation pitch and of the DLC resistivity have been performed.
From the 2021 beam test results, more...
Some say SUSY is dead, because LHC has not discovered it yet. But is this
really true? It turns out that the story is more subtle. SUSY can be 'just
around the corner', even if no signs of it has been found and a closer
look is needed to quantify the impact of LHC limits and their implications
for future colliders. In this contribution, a study of prospects for SUSY
based on scanning...
Most analyses of triple Higgs couplings (THCs) focused on the SM-like coupling, $\lambda_{hhh}$, assuming the SM value, $\kappa_\lambda := \lambda_{hhh}/\lambda_{hhh}^{\rm SM} = 1$.
We will discuss two BSM physics cases:
1) $\kappa_\lambda \neq 1$, which is suggested by the requirements for baryogenesis (to explain the the matter-antimatter asymmetry of the universe.
2) BSM THCs, such as...
The tracking system of the IDEA detector concept consists of different silicon detector subsystems: a vertex detector, an inner tracker and a silicon wrapper between the drift chamber and the calorimeters. Various technologies are being explored and optimized, depending on the physics and operating conditions of teh systems. The high-granularity and low-power ARCADIA prototypes have recently...
The detectors at future e+e- linear colliders will need unprecedented precision on Higgs physics measurements. These ambitious physics goals translate into very challenging detector requirements on tracking and calorimetry. High precision and low mass trackers, as well as highly granular calorimeters, will be critical for the success of the physics program. To develop the next generation of...
Measuring the Higgs self-coupling is a key target for future $e^{+}e^{-}$ colliders and can be accessed through double Higgs production. An important question is how the precision of this measurement improves with higher center-of-mass collision energy. In this work, we study the ZHH process at center-of-mass energies of 500, 550, and 600 GeV, simulated with the ILD detector concept from the...
The direct pair-production of the tau-lepton superpartner, stau, is one of the
most interesting channels to search for SUSY. First of all the stau is with high
probability the lightest of the scalar leptons. Secondly the signature of stau
pair production signal events is one of the most difficult ones, yielding the
'worst' and thus most general scenario for the searches.
The most...
The performance of monolithic CMOS pixel sensors depends on their fabrication process and especially the feature size which directly drives the pixel size. A consortium led by the CERN EP R&D program, the ALICE experiment and various European projects (AIDAinnova, EURIZON) is investigating the benefits of a 65-nm CMOS imager process to design a new generation of pixel sensors. These...
Long-range angular particle correlations may serve as manifestations of physics beyond the Standard Model, such as Hidden Valley (HV) scenarios. We focus on QCD-like hidden sectors in which the production of HV matter on top of the QCD partonic cascade would enhance and enlarge azimuthal correlations of final-state particles. We study the observability of such signals at future $e^+e^-$...
The precise reconstruction of electrons is an important ingredient for the proposed physics program at future Higgs factories (HF). It becomes especially important in $m_W$ and TGC measurements in the $e\nu W$ final state. These measurements were identified as two of the high-priority focus topics by the WG1 of the ECFA HF study.
The track reconstruction for electrons is particularly...
We analyze the electroweak (EW) sector of the MSSM in view of the experimental results for the anomalous magnetic moment of the muon, $(g-2)_\mu$, the Dark Matter (DM) relic density, the DM direct detection (DD) bounds and in particular the LHC searches for such EW particles. We demonstrate the complementarity of future DD experiments and future high-energy $e^+e^-$ colliders. We show that...
In a class of theories, dark matter is explained by postulating the existence of a 'dark sector',
which interacts gravitationally with ordinary matter. If this dark sector contains a U(1) symmetry,
and a corresponding 'dark' photon ($A_{D}$) , it is natural to expect that this particle with kineticly mix
with the ordinary photon, and hence become a 'portal' through which the dark sector can...
An effective field theory (EFT) approach is used to investigate naturalness of the Higgs sector at scales below $M \sim {\cal O}(10)$ TeV. In particular, we obtain the leading 1-loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff $\Lambda$ (i.e., $\Lambda < M$), and determine the constraints on the corresponding operator coefficients for these effects to alleviate...
We present the latest development for the FCC-ee interaction region and machine-detector interface (MDI). It represents a major challenge for the FCC-ee colliders, which has to achieve extremely high luminosity over a wide range of centre-of-mass energies. FCC-ee will host two or four high-precision experiments. The machine parameters have to be well controlled and the design of the...
Several indications for neutral scalars are observed at the LHC. One of them, a broad resonance peaked at about 650 GeV which we call H(650), was obtained by an outsider combining published histograms from ATLAS and CMS on ZZ →4ℓ searches, and this combination shows a local significance close to 4 s.d. Since then, CMS has reported two other indications at the same mass, with similar local...
The FCC-ee aims at unprecedented luminosities, to be able to study the Standard Model of particle physics with extreme precision. The vertex detector, located close to the beam pipe, plays a paramount importance in the precise reconstruction of the trajectories of the charged tracks.
In this contribution we will present the design of the IDEA vertex detector, as a result aiming to fulfil...
Particle flow and flavor tagging are the key algorithms determining physics performance at reconstruction for Higgs factory detectors. Particle flow is the reconstruction of individual particles inside jets, which requires precise track-cluster matching in addition to clustering of calorimeter hits. We are implementing a track-cluster matching algorithm on top of GravNet-based calorimeter...
There are no yet results on precision the CP violating Higgs mixing angle can be extracted in VBF at future Higgs factories. This is the first such study based on CP sensitive angular observable, using 1 ab-1 of simulated ILD data, at 1 TeV center of mass energy. The achievable experimental precision will be discussed in the light of goal sensitivity to 10% admixture of the CP-odd state.
The hadron collider phase of the Future Circular Collider (FCC-hh) is a proton-proton collider operating at a center-of-mass energy of 100 TeV. It is one of the most ambitious projects planned for the rest of this century and offers ample opportunities in the hunt for new physics, both through its direct detection reach as well as through indirect evidence from precision measurements....
The IDEA detector designed for the FCC-ee experiment has a cilindrical drift chamber as a main tracking device, surrounded by a spaghetti calorimeter exploiting a dual readout technology.
The fibers are positioned 1.5 mm far from each other giving to the detector an high granularity of about 50 sensitive element per cm2.
The Dual Readout technology, using scintillating and Cherenkov based...
Positron sources are the key elements for the future and current e-e+ collider projects, introducing challenging critical requirements for high intensity and low emittance beams in order to achieve high luminosity.
The conventional way to realize a e+ source consists in using a target with high atomic number Z hit by a high energy primary electron beam. Photons are produced by...
