The THDMa is a new physics model that extends the scalar sector of the Standard Model by an additional doublet as well as a pseudoscalar singlet and allows for mixing between all possible scalar states. In the gauge-eigenbasis, the additional pseudoscalar serves as a portal to the dark sector, with a priori any dark matter spins states. The option where dark matter is fermionic is currently...
Extensions of the Standard Model that include vector-like quarks commonly also include additional particles that may mediate new production or decay modes. Using as example the minimal linear $\sigma$ model, that reduces to the minimal $SO(5)/SO(4)$ composite Higgs model in a specific limit, we consider the phenomenology of vector-like quarks when a scalar singlet $\sigma$ is present. This new...
We studied phenomenological implications of numerious Family Non-Universal U(1)$^\prime$ sub-models in the minimal U(1)$^\prime$ extended Supersysmmetric Model (UMSSM) possesing an extra down quark type exotic field. In doing this, we started with anomaly cancelation criteria to generate a number of solutions in which the extra U(1)' charges of the particles are treated as free parameters....
The problematic huge hierarchy between the usual 4-dimensional Planck mass scale of gravity and the ElectroWeak symmetry breaking scale can interestingly disappear at some point-like location along extra space-like dimensions where the effective gravity scale is reduced down to the TeV scale. Field theories with point-like particle locations (3-dimensional brane-worlds) or point-like...
The recent tension between local and early measurements of the Hubble constant can be explained in a particle physics context. A mechanism is presented where this tension is alleviated due to the presence of a Majoron, arising from the spontaneous breaking of Lepton Number. The lightness of the active neutrinos is consistently explained. Moreover, this mechanism is shown to be embeddable in...
A new LCIO-based data format called mini-DST has been developed, which combines PFO- and event-level information, including the output of the most important high-level reconstruction algorithms.
Originally triggered by Snowmass 2021 studies, the mini-DST is useful for beginners as the starting point of analysis.
In this talk, we discuss the basics and contents of the mini-DST, how to use it...
The Event Data Model (EDM) is at the core of HEP experiments software frameworks. It defines the language in which physicists are able to express their ideas and also how the different software components communicate with each other. The Key4HEP project aims to develop a common software stack for future collider projects. One of the main components of Key4HEP is a common EDM in the form of...
In this talk, I will discuss a computational set-up for calculating the production of a massive quark-antiquark pair in $e^+e^-$ collisions at order $\alpha_s^2$ in the coupling of quantum chromodynamics (QCD) at the differential level by means of the antenna subtraction method.
Theoretical predictions on the production of top quark pairs in the continuum, and the bottom quark pairs at the...
Since 2020, CLIC and ILC take part in the Key4hep collaboration, which strives to create a common software for HEP collider design studies. Key4hep represents a flexible, multi-layered model of collaboration, where different common components like documentation, build system, data modeling, persistency and framework components are adopted as needed. This talks gives a bird's-eye view of...
We explore composite models with different manifestations of the Global symmetry (G) and its subgroup (H) it breaks into. One feature common to all is the possibility for the presence of one (or more) CP-odd scalar singlet states ("$\eta$") which are Goldstones of the breaking of the global symmetry. There exist possibilities where the corresponding mass corrections for the $\eta$ are highly...
To ensure the backward compatibility between iLCSoft and Key4hep and to ease the validation of the iLCSoft processors, k4MarlinWrapper provides the necessary tools to run Marlin processors using the Gaudi framework, allowing for a smooth transition from current battle-tested particle reconstruction frameworks, to a common framework for future experiments like CLIC or FCC. It creates a wrapper...
Using the method of massive operator matrix elements, we calculate the subleading QED initial state radiative corrections to the process $e^+ e^− \to \gamma^∗/Z^∗$ for the first three logarithmic contributions. The calculation is performed in the limit of large center of mass energies $s \gg m_e^2$.
These terms supplement the known corrections to $O(\alpha^2)$, which were completed...
The iLCDirac grid interface has been successfully used by Linear Collider community for many years. It has made it possible to isolate the users from the ever changing distributed environments by offering a consistent interface throughout the years. In this contribution we detail the current status and latest developments as well as the plans for keeping iLCDirac up-to-date with the latest...
We test the assumption that fermion-loop corrections to high energy W+W− scattering are negligible when compared to the boson-loop ones. Indeed, we find that, if the couplings of the interactions deviate from their Standard Model values, fermion-loop corrections can in fact become as important or even greater than boson-loop corrections for some particular regions of the parameter space, and...
We have produced new high statistics 250 GeV common MC samples
for the ILD physics study using the latest generator, simulation, and reconstruction packages.
Aiming for the requested statistics of MC samples for physics study,
we utilized ILCDIRAC distributed computing environment for mass production.
In this talk, we will report the estimated resource requirements
and the current...
The US Particle Physics Community Planning Exercise (aka Snowmass), sponsored by the APS Division of Particles and Fields, provides an opportunity for particle physicists in the US, together with international partners, to build consensus on possible future projects and explore their potential scientific reach. The Silicon Detector (SiD) is one of two mature detector concepts proposed for the...
Determination of the Higgs boson self-coupling is crucial for understanding the structure of the electroweak symmetry breaking vacuum. I will review the theoretical extraction of the self-coupling from observed cross sections of e+e- -> Zhh and e+e- -> vvhh at high energy, current projections of experimental sensitivity, and the limiting factors for this measurement.
In the Standard Model（SM）, ΗγZ coupling is a loop induced coupling, therefore it might receive relatively large correction from Beyond Standard Model（BSM） physics. It is very challenging to measure at the HL-LHC, where only 3σ significance is expected for branching ratio of H$\to$γZ. On the other hand, HγZ coupling is potentially very sensitive to new physics, for example some new heavy...
We report on studies of the e+e− → HZ process with the subsequent decay of the Higgs boson H → ZZ , where the ZZ combination is reconstructed in the final states with two jets and two leptons. The analysis is performed using Monte Carlo data samples obtained assuming the ILD detector model, the integrated luminosity 2 ab−1 and the center-of-mass energy √s = 250 GeV. Signals are measured for...
As a multi-TeV energy-staged machine, CLIC offers millions of Higgs bosons to be produced in a low-background environment enabling measurements of most of the Higgs couplings at a few per mille level. To this end, individual measurements at different CLIC energy stages, in various Higgs production and decay channels, are subjects of global fits of the Higgs properties in model-independent or...
In this talk we address a potential of 3 TeV center-of-mass energy Compact Linear Collider (CLIC) to measure the Standard Model (SM) Higgs boson decay to two photons. Since photons are massless, they are coupled to the Higgs boson at a loop level, in exchange of heavy particles either from the Standard Model or beyond. Any deviation of the Higgs to di-photon branching fraction and...
In Standard Model (SM) Higgs Boson pair production initiated by photons ($\gamma \gamma \to h h$) is loop-generated process and thereby is very sensitive to any new couplings and particles that may come in loops. Composite Higgs Models (CHMs) provide an alternate mechanism to address the hierarchy problem of SM where Higgs could be a bound state of a strongly interacting sector instead of...
A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is the reference design of the ECAL for International Large Detector (ILD) concept, one of the two detector concepts for the detector(s) at the future International Linear Collider. Prototypes for this type of detector are developed within the CALICE Collaboration. The technological prototype addresses technical...
The naturalness problem motivates new physics beyond the Standard Model (SM). The Higgs sector in neutral naturalness models provides a portal to the hidden QCD sector, and thus Higgs coupling measurements play a central role in exploring the model parameter space. We investigate a class of neutral naturalness models, in which the Higgs boson is a pseudo-Goldstone boson with the radial mode at...
A prototype of a digital pixel EM calorimeter, EPICAL-2, has been designed and constructed, following up on a previous prototype [1]. It consists of alternating W absorber and Si sensor layers, with a total thickness of ~20 radiation lengths, an area of $\mathrm{30mm\times30mm}$, and ~25 million pixels. The new EPICAL-2 detector employs the ALPIDE pixel sensors developed for the ALICE ITS...
The increase of the particle flux (pile-up) at the HL-LHC with luminosities of L ≃ 7.5 × 1034 cm−2s−1 will have a severe impact on the ATLAS detector reconstruction and trigger performance. The end-cap and forward region where the liquid Argon calorimeter has coarser granularity and the inner tracker has poorer momentum resolution will be particularly affected. A High Granularity Timing...
We study the process $e^+ e^- \to \ell^+ \ell^- h\left(b\bar{b}\right)$ considering centre-of-mass
energies $\sqrt{s} = \{250, 1000, 3000\} \, \text{GeV}$ using resolved- and boosted-analysis
techniques to reconstruct the Higgs boson. We show that this process probes the tensor
structure of the $hZZ^*/hZ\bar{f}f$ couplings via Higgs-strahlung and $Z$-boson fusion in the
dimension-six...
CMS is building a High Granularity sampling Calorimeter (HGCAL), which will replace the existing endcap calorimeters (electromagnetic and hadronic) as part of the CMS phase-II upgrade to prepare for the High-Luminosity phase of the LHC (HL-LHC), due to start around 2027. The HGCAL includes two compartments: the CE-E and CE-H for measurements of electromagnetic and hadronic showers...
We study the measurement of Higgs boson self-couplings in $2\rightarrow 3$ vector boson scattering processes in proton colliders and lepton colliders in the framework of Standard Model Effective Field Theory, taking the examples of $W^{\pm}_L W^{\pm}_L\rightarrow W^{\pm}_L W^{\pm}_L h$ and $W^+_L W^-_L\rightarrow h h h$. First, by taking Goldstone equivalence theorem and analysing the...
Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains arbitrary number of scalar and fermion fields with arbitrary electric and chromoelectric charges. The BSM Higgs sector is described by using the non-linear sigma...
Electroweakly Interacting Massive Particles (EWIMP) is one of the best dark matter candidates as represented by Wino or Higgsino in SUSY. There are several methods to search for such particles at collider, and one of them is using indirect probe, which is as follows. EWIMP modifies the self energy of electroweak gauge bosons via loop contribution, and this result in a slight change in the...
A Monolithic CMOS Pixel Sensors (CPS), named MIMOSIS, is currently being developed by IPHC/IKF/GSI to equip the Micro-Vertex Detector (MVD) of the CBM heavy ion experiment at FAIR/GSI in the TJ 180nm technology. It features about 500 000 pixels with in-pixel discrimination and data driven read-out. The first full size prototype (MIMOSIS-1) has been fabricated in 2020 in different epitaxial...
Future $e^+e^-$ colliders are excellent tools to probe fundamental physics beyond Standard Model via Higgs and electroweak precision measurements.
Modern silicon detectors are able to measure time-of-arrival with high precision of O(10 ps). This can be used to measure the time-of-flight (TOF) of the particles and improve their identification.
We develop reconstruction and calibration...
Compact Linear Collider (CLIC) was proposed as the next energy-frontier infrastructure at CERN, allowing to study $e^{+}e^{-}$ collisions at three centre-of-mass energy stages: 380 GeV, 1.5 TeV and 3 TeV. The main goal of its high-energy stages is to search for the new physics beyond the Standard Model (SM). The Inert Doublet Model (IDM) is one of the simplest SM extensions and introduces four...
The Silicon Pixel Tracker (SPT), a 30 Gpixel detector, was first proposed at LCWS2008 as an improvement to the baseline ILC tracking systems. Since then there has been huge progress in the field, with developments such as the 12.5 Gpixel ITS2 for ALICE. We report on how this and other progress has enabled an even better performance spec than in 2008, using state-of-art Monolithic Active Pixel...
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 to the 'worst' and so most global scenario for the searches.
The current...
The last decades have seen the development of calorimeters with pixels smaller than 1 cm² or even 1 cm³ considering the extent in depth. Today it looks possible to measure the time of the pixel energy deposits with a resolution similar to their size (1 cm = 30 ps), even though limitations linked to technology will come in. What can bring such a performance to the performances of the...
The CLIC Tracker Detector (CLICTD) is a monolithic pixel sensor featuring pixels of 30 microns x 37.5 microns and a small collection diode. The sensor is fabricated in a 180 nm CMOS imaging process, using two different pixel flavours: the first with a continuous n-type implant for full lateral depletion, and the second with a segmentation in the n-type implant for accelerated charge...
We introduce here a new method to measure the Higgs decay branching ratios at future e⁺e⁻ Higgs factories, by directly exploiting class numeration.
Given the clean environment at a lepton collider, we build an event sample highly enriched in Higgs bosons and essentially unbiased for any decay mode.
The sample can be partitioned into categories using event properties linked to the expected...
To face the increase of radiation levels and to maintain the high physics performance during the HL-LHC, an upgrade of the Compact Muon Solenoid (CMS) experiment will replace the existing forward calorimeters with a new high granularity sampling calorimeter (HGCAL). The current design of HGCAL uses silicon sensors as active material in the highest radiation regions and plastic scintillator...
CMOS sensors (MIMOSA like) were successfully implemented in the STAR tracker. LHC experiments have shown that efficient B tagging, reconstruction of displaced vertices and identification of disappearing tracks are necessary (1-2). An improved vertex detector is justified for the ILC. To achieve a point-to-point resolution below the one-µm range while improving other characteristics (radiation...
International Large Detector, ILD is a detector concept of the ILC. It is required to measure various kinds of the final state particles very precisely using ILD and jet energy scale (JES) measurement is one of the important parts. In order to reduce the systematic error of the JES measurement, we tried to calibrate the jet energy using reconstructed jet energy from other measured variables....
One of the important goals at the future $e^+e^-$ colliders is to measure
the top-quark mass and width in a scan of the pair production threshold.
However, the shape of the pair-production cross section at the
threshold depends also on other model parameters, as the top Yukawa
coupling, and the measurement is a subject to many systematic uncertainties.
Presented in this work is the most...
The vast majority of foreseen upgrades to existing particle physics detectors, as well as future Linear Collider experiments will continue to be based on silicon sensors as main tracking device. This means sensors will become even more of a cost driver than they already are today. In addition, sensors in the Float-Zone technology currently used in the LHC experiments are available from only a...
In supersymmetric extensions of the Standard Model,higgsino-like charginos and neutralinos are preferred to have masses of the order of the elecktroweak scale by naturalness arguments. Light higgsinos are also well motivated from a top-down perspective. Such light $\tilde{\chi}^{\pm}_{1}$, $\tilde{\chi}^{0}_{1}$ and $\tilde{\chi}^{0}_{2}$ states can be almost mass degenerate. In this talk the...
Despite the discovery of the Higgs boson with a mass of 125 GeV, the structure of the Higgs sector remains unknown. In light of the current situation that a second Higgs boson has not been discovered, indirect searches of such a new particle through observables for Higgs bosons are more and more important. This requires accurate theoretical predictions for such observables in order to compare...
In the framework of the CP conserving Two Higgs Doublet Model (2HDM), type I and II, we analyze the sensitivity to triple Higgs couplings at future high(er) energy electron-positron colliders, such as ILC and CLIC. We study the production cross section of two neutral Higgs bosons in two channels: $e^+e^-\to h_i h_j Z$ and $e^+ e^- \to h_i h_j \nu \bar{\nu}$ within several benchmark planes...
The 2HDMS is based on the CP-conserving 2HDM extended by a complex singlet
field. We impose an additional Z3 symmetry on the potential. This leads to a
Higgs-sector similar to the Next-to-Minimal Supersymmetric SM (NMSSM),
while having fewer symmetry conditions compared to supersymmetric models. We
introduce the theoretical background of this model and set it up for
phenomenological...
CMS reported a ∼ 3$\sigma$ excess at ∼ 96 GeV in the $pp\rightarrow H\rightarrow\gamma\gamma$ channel. In the same mass range, a ∼ 2$\sigma$ excess in the $e^+ e^-\rightarrow Z H, H\rightarrow b\bar{b}$ channel has been reported at LEP as well. We interpret the experimental excesses as the lightest Higgs boson in the Two-Higgs-Doublet Model with a complex singlet (2HDMS) with type II Yukawa...
We present the current status of the assessment of the theoretical issues involved in reaching the targeted 0.01% precision for the FCC-ee/LC luminosity prediction. We also discuss its synergies with other precision theory requirements and efforts for the FCC-ee/LC physics programs.
The Electromagnetic Calorimeter (ECAL) of the CMS detector has played an important role in the physics program of the experiment, delivering outstanding performance throughout data taking. The High-Luminosity LHC will pose new challenges. The four to five-fold increase of the number of interactions per bunch crossing will require superior time resolution and noise rejection capabilities. For...
The Silicon-Tungsten ECAL (SiW-ECAL) of ILD will require about 10,000 detector slabs of 1.4 to 1,8 m in length. For the ease for building and testing, the slabs are made of stitched detector elements of 18×18 cm², composed of a Front-End Board (FEB), hosting the readout ASICs for 1024 channels, on which the Silicon sensors are glued.
Various types of detector elements have been successfully...
While the Standard Model (SM) predicts a branching ratio of the Higgs boson decaying to invisible particles of O(0.001), the current measurement of the Higgs boson coupling to other SM particles allows for up to 20% of the Higgs boson width to originate from decays beyond the SM (BSM). The small SM-allowed rate of Higgs boson decays to invisible particles can be enhanced if the Higgs boson...
The matter-antimatter asymmetry of the universe may result at least partially from CP violation. CP violation in mesons and neutrinos is too small to account for matter-antimatter asymmetry, motivating a search for CP violation in the Higgs sector. We present a study of the potential measurement of CP symmetry of the Higgs boson at the International Linear Collider (ILC) by the SiD experiment....
The Tile Calorimeter (TileCal) is a sampling hadronic calorimeter covering the central region of the ATLAS experiment. TileCal uses steel as absorber and plastic scintillators as active medium. The scintillators are read-out by the wavelength shifting fibres coupled to the photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped, digitized by sampling the signal...
The Analog Hadron Calorimeter (AHCAL) concept developed by the CALICE collaboration is a highly granular sampling calorimeter with 3*3 cm^2 plastic scintillator tiles individually read out by silicon photomultipliers (SiPMs) as active material.
After building a large technological prototype and testing it in particles beams at DESY and CERN in 2018, the hardware developments and tests are now...
We examine the region of the parameter space of the Next to Minimal
Supersymmetric Standard Model (NMSSM) and the Minimal Supersymmetric Standard Model~(MSSM) with a light neutralino~($M_{\tilde{\chi}_1^0} \leq$~62.5~GeV) where the SM-like Higgs boson can decay invisibly, the thermal neutralino relic density is smaller than the measured cold dark
matter~(DM) relic density, and where...
We investigate a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. For this the Minimal Supersymmetric Standard Model is extended by adding light right-handed neutrinos and their superpartners, the R-sneutrinos. Moreover, we consider the lightest neutralinos to be higgsino-like. We first update a previous analysis and assess to...
The Semi-Digital Hadronic CALorimeter (SDHCAL), developed within the CALICE collaboration, is proposed to equip the future ILD detector of the ILC.
A technological prototype has successfully has provided excellent results in terms of energy linearity and resolution but also tracking and PID capabilities.
To validate completely the SDHCAL option for ILD, new R&D activities have started. The...
Right handed neutrino is proposed as the extended of SM. We consider the possibility of exploring the RHN at ILC500. We study the RHN pair production using Delphes mini-DST.
We are developing kinematic fitter which can deal with arbitrary resolution functions. Kinematic fitting is the constrained optimization method which uses distributions of fit parameters and kinematic relations among the parameters. In order to treat non-Gaussian distributions, for example b-jet energy distribution, our kinematic fitter is implemented based on the log-likelihood method.
In...
Sophisticated machine learning techniques have promising potential in search for physics beyond Standard Model (BSM) in Large Hadron Collider (LHC). Convolutional neural networks (CNN) can provide powerful tools for differentiating between patterns of calorimeter energy deposits by prompt particles of Standard Model and long-lived particles predicted in various models beyond the Standard...
The Circular Electron Positron Collider (CEPC) has been proposed for Higgs factory in the next few decades. To achieve the required performance precision, it is critical to optimize the design of the Machine-Detector-Interface(MDI), as well as the Interaction Region(IR). In this work, we will present the latest design and study status of the CEPC MDI IR, covering the overall introduction,...
In this talk, we show the recent results of our R&D works on the Machine Learning Application to the Collider Experiments.
In RCNP, Osaka University, in Japan, we form a group which consists with about 20 researchers on both information science and collider physics (experiment and theory) to work on the R&D of machine learning application to the collider experiments, as a research project in...
Extended Higgs models with CP violation have a possibility to solve the baryon number asymmetry of the universe by electroweak baryogenesis. However, the electric dipole moment (EDM), which is highly sensitive to new CP-violating effects, has not been observed so far. In this talk, we consider the testability of CP violation of a scenario in which the EDM is suppressed by cancellation among...
The uncertainty of energy measurement of the circular electron-positron collider beam is required to be less than $10 \mathrm{MeV}$ for accurate measurement the Higgs/W/Z bosons' mass. It's proposed a new scheme of microwave-beam Compton backscattering to measure the beam energy by detecting the maximum energy of scattered photons. Choosing the ${TM_{010}}$ mode of the standing wave cavity,...
Jet clustering is one of the main key to obtain better physics results because
reducing mis-clustring leads to improve the mass resolution of the resonances especially in multi-jet situation.
Present jet clustering is far from a good tool for reconstructing jets. We need to tackle the problem
and should explore the possibility of constructing better jet clustering algorithm.
Recently,...
We study the search for an extra scalar S boson produced in association with the Z boson at the
International Linear Collider (ILC). The study is performed at center-of-mass energies of 250
GeV and 500 GeV based on the full simulation of the International Large Detector (ILD). In
order to be as model-independent as possible, the analysis uses the recoil technique, in particular
with the Z...
The Compact LInear Collider (CLIC) is a proposed TeV-scale high-luminosity electron-positron collider at CERN. CLIC will allow us to study the Higgs boson properties with very high precision. These measurements can also result in a direct or indirect discovery of "new physics", Beyond the Standard Model (BSM) phenomena, which could help us to understand the nature of dark matter (DM). SM-like...
We developed a novel algorithm of vertex finding for future lepton colliders such as the International Linear Collider. We deploy two networks; one is simple fully-connected layers to look for vertex seeds from track pairs, and the other is a customized Recurrent Neural Network with an attention mechanism and an encoder-decoder structure to associate tracks to the vertex seeds. The performance...
One of the primary goals of the proposed future collider experiments is to search for dark matter (DM) particles using different experimental approaches. High energy $e^+e^-$ colliders offer unique possibility for the most general search based on the mono-photon signature. As any $e^+e^-$ scattering process can be accompanied by a hard photon emission from the initial state radiation, analysis...
Tau lepton physic plays an important role in the research programme at future e+e- experiments. To fully exploit the physics potential of machine and experiments, and for a cost-effective detector design, it is important to to implement from start advanced Machine Learning methods in the development of the detector. With this respect we report here on an ongoing study on τ-identification...
It is commonly believed that Dark Matter (DM) should exist in the form of new, Beyond-the-Standard-Model stable particles.
Such particles, however, have not yet been detected, which means that interactions between DM and SM must be very weak. Dark particles, even if they are already produced at existing colliders, evade detection due to tiny signal-to-background ratio.
Future $e^+e^-$...
Accurate simulation of physical processes is
crucial for the success of modern particle physics.
However, simulating the development and interaction of particle showers with calorimeter detectors is a time consuming process and drives the computing needs of large experiments at the LHC and future colliders. Recently, generative machine
learning models based on deep neural networks have...
The precision-measurement goals for the Linear Collider detectors place strict constraints on the pixel size and the amount of material allowed in the vertex and tracking layers. Low-mass interconnect technologies suitable for small pitch hybridization as well as for the integration of modules are therefore required. An alternative pixel-detector hybridization technology based on Anisotropic...
The EUDET/AIDA beam telescopes are instruments widely used within the experimental high energy physics community, e.g by the detector groups of the LHC experiments, Belle-II, and of course by future linear collider groups. They provide an excellent pointing resolution of down to 2μm even at energies as low as O(1GeV), which makes them very well suited as reference tracking systems at the...
Beam telescopes at test beam facilities are a key technology driver for the design of high precision silicon trackers, both as a test bed for new technologies and to verify their performance. The Lycoris strip telescope is a new large active area beam telescope designed, as part of the AIDA 2020 project, as a general infrastructure upgrade for the DESY II Test Beam Facility. The main component...
In this contribution, we will present the status of the technological developments at IMB-CNM to fabricate 50 m thick Inverse Low Gain Avalanche Detectors (iLGAD) for pixelated timing detectors.
The iLGAD sensor concept is one of the most promising technologies for enabling the future 4D tracking paradigm that requires both precise position and timing resolution. In the iLGAD concept, based...
Future high-energy $e^{+}e^{-}$ colliders will provide some of the most precise tests of the Standard Model. Statistical uncertainties are expected to improve by orders of magnitude over current measurements.
This provides a new challenge in accurately assessing and minimizing systematic uncertainties. Beam polarisation may hold a unique potential to isolate and determine the size of...
Measuring Higgs properties is one of the most important research topics at the Higgs factory.
In this talk, we discuss the prospects of measuring the branching fraction of the Higgs boson decaying into muon pairs at the ILC.
We also discuss the impact of the transverse momentum resolution for this analysis.
In the first part of this contribution, the principles of operation of AC-LGAD, the first silicon detector based on resistive read-out, are illustrated. Then, we outline how AC-LGADs can enable the construction of a low-mass low-power silicon tracker with excellent spatial (2-3 microns/hit) and temporal (20 ps/hit) resolutions.
We report here the experimental prospects on the measurement of cross section and the forward-backward asymmetry for quark and antiquark production in electron positron collisions at 250 GeV at the International Linear Collider operating polarised beams. Thanks to the beam polarisation, we can separate the four independent chirality combinations of the electroweak couplings maximizing in this...
We developed an interdisciplinary fs-laser-based unique technology platform to test and explore new frontiers in light and optics to build up new knowledge that could advance existing strategies for further silicon technology development, emphasizing LGAD timing sensors. In collaboration with ELI Beamlines facility and ELI BioLab, the advanced fs-laser-based TCT/SPA-TPA infrastructure will...
FCAL performs R&D for highly compact electromagnetic calorimeters foreseen to instrument the very forward region of a detector at future e+e− colliders. Two special calorimeters are foreseen, the Luminosity Calorimeter (LumiCal) and the Beam Calorimeter (BeamCal), for a precise and fast, potentially bunch-by-bunch, luminosity measurement. During the last years FCAL has studied finely-segmented...
A new method is presented to extract quark masses from collider data on Higgs production and decay rates. We find a value for the bottom quark MSbar mass at the scale of the Higgs boson mass of mb(mh) = 2.6 +/- 0.3 GeV from recent measurements by ATLAS and CMS. This result is compatible with the prediction of mb(mh) from the evolution of the world average for mb(mb) and thus provides further...
A MPGD (Micro Pattern Gaseous Detector) based TPC can provide higher tracking resolution thanks to its small ExB effect compared to MWPC based detectors. We're investigating 2-track separation capability for a GEM-based TPC using electron beam. Since there is not much multi-track for each event, we have produced a pseudo multi-track event merging 2 events. We will report the details of the...
The violation of the CP symmetry is one of Sakharov's conditions for the matter/anti-matter asymmetry of the Universe. Currently known sources of CP violation in the quark and neutrino sectors are insufficient to account for this. Is CP also violated in the Higgs sector? Could the 125 GeV mass eigenstate be a mixture of even and odd CP states of an extended Higgs sector, or is CP explicitly...
The very high luminosity reach of the FCC-ee is obtained by having separate storage rings for electrons and positrons, which cross at a +/- 15 mrad angle at the interaction points, and by strong focussing obtained via by a set of quadrupoles the last of which has it face at L*=2.2 m from the IP. The crossing of the beam lines by the detector solenoidal field necessitates the insertion of a set...
Particle identification is one of the most important and difficult goal for high energy physics.
Ionization of matter by charged particles is the primary mechanism used for particle identification (dE/dx), but the large and inherent uncertainties in total energy deposition represent a limit to the particle separation capabilities: even in the most favorable momentum region (relativistic...
Neutrinos are probably the most mysterious particles of the Standard Model. The mass hierarchy and oscillations, as well as the nature of their antiparticles, are being currently studied in experiments around the world. Moreover, in many models of the New Physics, baryon asymmetry or dark matter density in the universe are explained by introducing new species of neutrinos. Among others, heavy...
A prime target of the ILC physics program is the precision measurement of the masses of known fundamental particles such as the top quark and the Higgs, W, and Z bosons. The measurement of the absolute center-of-mass energy scale is a primary issue for most determinations, and this will rely critically on the knowledge of the tracker momentum scale. By using particle decays, especially of...
The alignment of a detector aims at the description of the detector geometry as accurately as possible, such that the tracking resolution is not degraded by detector misalignments. The algorithm used for the alignment of the Inner Detector (ID) of the ATLAS experiment consists of a minimisation of the track-to-hit residuals in a sequence of hierarchical levels, ranging from the mechanical...
Future e+e- colliders are prime tools to search for physics Beyond the Standard Model charged under the electroweak force only. A particular example are scalar partners of the charged leptons, known as sleptons in supersymmetric extensions of the Standard Model. The decays of such scalar lepton partners involve additional neutral fermions (neutralinos in supersymmetric models), which are good...
The very forward region of a detector at future e+e- collider is the one of the most challenging regions to instrument. A luminometer – compact calorimeter dedicated for precision measurement of the integrated luminosity at a permille level or better is needed. Here we review a feasibility of such precision at CEPC, considering systematic effects arising from the detector mechanical precision...
A study of prospects for SUSY based on scanning the relevant
parameter space of (weak-scale) SUSY parameters, is presented. In
particular, I concentrate on the properties most relevant to evaluate
the experimental prospects: mass differences lifetimes and decay-modes.
A scan over SUSY parameter space was done, requiring that the NLSP
was a bosino or a stau - the hardest cases - with mass...
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...
Like at the LHC, tests of neutrino mass models will constitute a leading component of the new physics programs at proposed experiments such as the ILC, CepC/CppC, and FCC-ee/hh. This challenge requires the engineering of new search strategies, employing novel production mechanisms, and ultimately the development of Monte Carlo (MC) simulation software that feed into modern simulation tool...
The discovery of the Higgs boson has revealed that the Higgs quartic coupling becomes small at very high energy scales. Guided by this observation, we introduce Higgs Parity, which is a spontaneously broken symmetry exchanging the standard model Higgs with its parity partner. In addition to explaining the small Higgs quartic coupling, Higgs Parity can provide a dark matter candidate, solve the...
We present two new extractions of the QCD coupling constant at the Z pole, $\alpha_S(m_Z)$, from detailed comparisons of inclusive W and Z hadronic decays data to state-of-the-art perturbative Quantum Chromodynamics calculations at next-to-next-to-next-to-leading order (N$^{3}$LO) accuracy, incorporating the latest experimental and theoretical developments. In the W boson case, the total width...
In this talk I will describe our recent work on N$^3$LL+NNLO resummed prediction for 2-jettiness differential distribution for boosted $t\bar t$ pairs produced in $e^+e^-$ collisions calculated in the framework of SCET+(boosted) HQET. The prediction incorporates a precise short distance top mass scheme, such as the MSR scheme. Renormalon subtractions in the mass and soft function play a key...
Precision studies of the Higgs boson at future $e^+e^-$ colliders can help to
shed light on fundamental questions related to electroweak symmetry breaking,
baryogenesis, the hierarchy problem, and dark matter.
The main production process, $e^+e^- \to HZ$, will need to be controlled with
sub-percent precision, which requires the inclusion of next-to-next-to-leading
order electroweak (NNLO)...
In this talk, we present the results for constraining the effective field theory describing the top quark couplings through the $e^{-} e^{+} \rightarrow t \bar{t}+$jet process.
The analysis is performed at two center-of-mass energies of
500 and 3000 GeV considering a realistic simulation of the detector response and the main sources of background.
The expected upper limits at 95\% CL are...
The need for fast detector simulation programs is emphasised, both
in terms of the need for ``rapid response'' to new
results - in particular from the LHC - and new theoretical ideas,
and in terms of how to cope with multi-billion simulated event samples.
The latter would arise both from the need to be able to
simulate significantly more events than expected in the real data, also...
One of the important goals of the proposed future $e^+e^-$
collider experiments is the search for dark matter particles
using different experimental approaches. The most general search
approach is based on the mono-photon signature, which is expected
when production of the invisible final state is accompanied by a
hard photon from initial state radiation. Analysis of...
KKMCee is providing high precision Standard Model predictions for the lepton or quark pair production process at any future lepton colliders (excluding Bhabha process, including muon colliders). It features second order QED photonic corrections with advance soft photon resummation at the amplitude level and full control over longitudinal and transverse polarizations both for beams an outgoing...
The 4-, 5- and 6-jet resolution scales for the Durham jet algorithm in $e^+ e^-$ collisions are resummed, using an implementation of the well known CAESAR formalism within the Sherpa framework. Results are presented at NLO+NLL' accuracy. In particular the impact of subleading colour contributions is evaluated. Hadronisation corrections are studied using matrix-element plus parton-shower...
To achieve the physics requirements in the future e$^+$e$^-$ collider, the high resolution tracker for the particle track reconstruction and particle identification are demanded. Time Projection Chamber(TPC) is one of the main concept proposal of the central tracker detector, it has an excellent performance on the moment measurement, dE/dx measurement and the spatial resolution.
Based on the...
Searches for light, weakly coupled particles are an important component of the physics program at present and future colliders. A classic benchmark for a potential vector-boson mediator between the standard model and the dark sector is the hypothetical dark photon, which could be produced either directly or through a dark Higgs boson. As part of the US Snowmass process, we are studying the...
We discuss a possibility that the parameter space of the two Higgs doublet model is significantly narrowed down by considering the synergy between direct searches for additional Higgs bosons at the (HL-)LHC and precision measurements of the Higgs boson properties at future e+e- colliders such as the International Linear Collider (ILC). We show that, in the case where the coupling constants of...
Two fermion production at the International Linear Collider (ILC) will allow sensitive indirect
searches for new interactions, e.g. such as heavy gauge boson Z ′. Tools available at ILC to
measure the chirality of such new interactions include the ILC s polarised beams and the tau lepton
polarisation.
Tau polarisation is extracted by measuring the distribution of tau decay products, and...
We propose to utilize angularity distributions in Higgs boson decay to probe light quark Yukawa couplings at $e^+e^-$ colliders. Angularities $\tau_a$ are a class of 2-jet event shapes with variable and tunable sensitivity to the distribution of radiation in hadronic jets in the final state. Using soft-collinear effective theory (SCET), we present a prediction of angularity distributions...
A high performance central tracker is essential for precision measurements of Higgs properties at the ILC. The LCTPC-Asia group is developing a GEM based readout module for a TPC proposed as the central tracker of the ILD. Results from its test beam data taken in 2016 at DESY with the large prototype TPC (LP1) were reported multiple times in the past workshops of this series. This time we...
In the context of the Energy Frontier of Snowmass 2021, we are developing a neural network tagger for identifying the flavour of a jet with a physics focus on strange decays of Higgs bosons. The tagger will be deployed as part of prospect studies for SM H->ss measurements as well as for BSM heavy Higgs measurements, H(+)->cs, at future lepton colliders. In particular, these studies are...
In this talk, I discuss the phenomenology of a minimal model for GeV-scale Majorana dark matter (DM) coupled to the standard model lepton sector via a charged scalar singlet. The theoretical framework extends the Standard Model by two $SU(2)_L$ singlets: one charged Higgs boson and a singlet right-handed fermion. The latter plays the role of the DM candidate. We show that there is an...
The largest phase-1 upgrade project for the ATLAS Muon System at Large Hadron Collider (LHC) is the replacement of the present first station in the forward regions with the New Small Wheels (NSWs). The NSWs consist of two detector technologies: Large size multi-gap resistive strips Micromegas (MM) and small-strip Thin-Gap Chamber (sTGC). The sTGC modules are called “trigger chambers” and...
It has been considered that final assembly of the ILD solenoid should be carried out at an assembly hall which is ground floor of the experimental cavern, because the completed ILD solenoid is too huge to be delivered from the factory. While referring to CMS fabrication experience, we have been discussing manufacture plan with production companies. One third block of coil winding can be...
We will present the motivation to study ee->ss. In addition we will present first data quality checks with recently produced two-fermion samples at 250 GeV for ILD. These checks concern in particular Kaon identification that exploit the dE/dx capabilities of the ILD-TPC.
The leptophilic weakly interacting massive particle (WIMP) is realized in a minimal renormalizable model scenario where scalar mediators with lepton number establish the WIMP interaction with the standard model (SM) leptons. We perform a comprehensive analysis for such a WIMP scenario for two distinct cases with an SU(2) doublet or singlet mediator considering all the relevant theoretical,...
Developments for a TPC at ILC with MPGD readout have been conducted for more than two decades. A new scheme (called ERAM) for charge spreading with a resistive-capacitive anode has been recently tested in a beam at DESY. Preliminary results are presented. It is shown that this new scheme, where the Micromegas mesh is at ground, allows the distortions near the module boundaries to be reduced by...
The Standard Model(SM) can not explain why measured quark masses have different values and why the mass disparity between them. However, we can consider the energy dependence of quark mass, and these values change from measured values at a higher energy scale. Furthermore, some new particles such as SUSY contribute, this energy dependence will deviate from the SM's expectation. Based on this...
In this talk we will discuss about a general anomaly free U(1) extension of the Standard Model which describes a small neutrino mass after the seesaw mechanism. In this scenario a new force carrier called 𝑍′ Can be introduced which plays an interesting role to study a variety of phenomenological aspects including forward backward asymmetry, left right asymmetry, Higgs physics and dark matter...
The Higgs boson decay modes to heavy $b$ and $c$ quarks are crucial for the Higgs physics studies. The presence of semileptonic decays in the jets originating from $b$ and $c$ quarks causes missing energy due to the undetectable neutrinos. A correction for the missing neutrino momenta can be derived from the decay kinematics up to a two-fold ambiguity. The correct solution can be identified by...
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 in 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...
Highly granular electromagnetic calorimeter based on scintillator strip with SiPM readout (Sc-ECAL) is under development in the framework of the CALICE collaboration for future electron-positron colliders such as ILC and CEPC. The fully integrated technological prototype with 32 layers has been constructed to demonstrate the performance of Sc-ECAL with more realistic technical implementation....
Material budget and distance to the interaction point are amongst the key sensor performance figures that determine the tracking and vertexing capabilities of inner tracking systems. To significantly improve these numbers, ALICE is carrying out the R&D for replacing its inner-most tracking layers by truly cylindrical layers made from wafer-scale, bent sensors (Inner Tracking System 3, "ITS3")....
strong text We present status of scintillator ECAL development in Shinshu University. In particular, we are manufacturing and adjusting an ILC type module that integrates a readout electronic circuit and a scintillator sensor in a layer. We have manufactured two layers of such module, and have made fine adjustments to calibrate. Currently, we are conducting performance verification using...
For the HL-LHC upgrade the current ATLAS Inner Detector is replaced by an all-silicon system. The Pixel Detector will consist of 5 barrel layers and a number of rings, resulting in about 14 m2 of instrumented area. Due to the huge non-ionizing fluence (1e16 neq/cm2) and ionizing dose (5 MGy), the two innermost layers, instrumented with 3D pixel sensors (L0) and 100μm thin planar sensors (L1)...
The Higgs trilinear coupling can serve as a unique probe to investigate the structure of the Higgs sector and the nature of the electroweak phase transition, and to search for indirect signs of New Physics. At the same time, classical scale invariance (CSI) is an attractive concept for BSM model building, explaining the apparent alignment of the Higgs sector and potentially relating to the...
The scintillator-based electromagnetic calorimeter (ScECAL) is one of the technology options for ECAL at future electron-positron colliders. The performance of double-sided SiPM redout method on scintillator strip and strip-SiPM misalignment effect have been studied in lab test. The performance of the calorimeter with a realistic design of the scintillator strip including the measured...
The experimental measurements on flavour physics, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson coefficients assuming a model independent effective Hamiltonian approach, by including a proposal of different scenarios to include the New Physics contributions. A...
The Mu3e experiment searches for the lepton flavour violating decay µ→ eee with an ultimate aimed sensitivity of 1 event in 10^16 decays. This goal can only be achieved by reducing the material budget per tracking layer to X/X0 ≈ 0.1 %. High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) which are thinned to 50 µm serve as sensors. Gaseous helium is chosen as coolant. This talks presents...
A light pseudoscalar in extended Higgs sector provides solution to muon anomalous magnetic moment and/or dark matter. We explore the prospect of Yukawa production of such a light boson which can exist in an extended Higgs sector like 2HDM. Considering ILC "Higgs factory" with CM Energy of 250 GeV, we show that the available parameter space can be examined by the (tau) Yukawa process at 5 sigma...
Electromagnetic calorimeter based on scintillator strip with SiPM readout (Sc-ECAL) is one of the technology options for the ECAL at the International Linear Collider (ILC). The SiPM output will become non-linear light when a large amount of light is injected to SiPM and SIPM saturates. The SiPM saturation is measured with a new method based on scintillation light excited by injecting UV-laser...
The success of the Belle II experiment relies for a large part on the very high instantaneous luminosity, close to 8x10^35 cm^-2.s^-1, expected from the SuperKEKB collider. The beam conditions to reach such luminosity levels generate a large rate of background particles in the inner detection layers of Belle II, which exceeds by far the rate of particles stemming from elementary collisions....
We study the scenario of the two Higgs doublet model, where the Higgs potential respects the twisted custodial symmetry at high energy scale. In this scenario, experimental data for the Higgs boson couplings and those for the electroweak precision observables can be explained even when the masses of the extra Higgs bosons are near the electroweak scale. We also discuss the predictions on the...
A prototype of a digital pixel electromagnetic calorimeter, EPICAL-2, was designed and constructed. It consists of a sandwich construction of W absorbers and Si sensor layers, with a total thickness of approximately 20 radiation lengths and a cross section of $\mathrm{30\,mm\times30\,mm}$. This design is the next step in pixel calorimetry following up on a previous prototype using MIMOSA...
The Semi-Digital Hadronic Calorimeter (SDHCAL) is proposed to equip the future ILD detector at ILC. A technological prototype of the SDHCAL developed within the CALICE collaboration has been extensively tested in test beams. The talk will summarize the prototype performances in terms of hadronic shower reconstruction from the most recent analyses test beam data.
I discuss how to employ collinear factorisation theorems for the computation of generic hard-production processes at e+e- colliders, in particular by stressing the strong analogies with their analogues which are routinely used in the context of LHC physics. I shall briefly describe some recent work on the universal behaviour associated with small-angle emissions in QED, that leads to the...
The Analog Hadron Calorimeter (AHCAL) concept developed by the CALICE collaboration is a highly granular sampling calorimeter with 3*3 cm^2 plastic scintillator tiles individually read out by silicon photomultipliers (SiPMs) as active material. We have built a large scalable engineering prototype with 38 layers in a steel absorber structure with a thickness of ~4 interaction length. The...
Applications of Quantum Chromodynamics to collider phenomenology largely rely on factorization, the separation of universal low-energy dynamics from perturbative high-energy physics. Factorization of cross sections was originally established at the leading power in an expansion in the ratio of these energies, but in view of precision physics subleading terms become relevant. I will present...
WHIZARD is a multi-purpose Monte Carlo event generator very well suited for the simluation of lepton collider physics.
In this talk, we are reporting on the recent theoretical and technical developments with respect to the implementation of next-to-leading-order perturbative corrections and the UFO interface to use models beyond the Standard Model within WHIZARD.
