We present a search for the charged Higgs boson via $e^+ e^-→H^+ H^-→b ̅cbc ̅$ at the 500 GeV ILC. In a general two Higgs doublet model without $Z_{2}$ symmetry, extra Yukawa couplings such as $\rho_{tc}$ and $\rho_{tt}$ can drive baryogenesis, but searches at the HL-LHC may still come away empty-handed. In this report, we take $m_(H^+ )=m_H=m_A=200$ GeV with $\rho_{tc}=\rho_{tt}=0.1$, and no...
We explore a novel possibility that dark matter has a light mass below 1 GeV in a lepton portal dark matter model. There are Yukawa couplings involving dark matter, left-handed leptons and an extra scalar doublet in the model. In the light mass region, dark matter is thermally produced via its annihilation into neutrinos. In order to obtain the correct relic abundance, a neutral scalar is...
The scenario of electroweak baryogenesis in the CP violating extended Higgs model has been strongly limited by current EDM experiments, hence it is difficult to generate the observed baryon density in our universe. Recently, in the CP violating Two Higgs doublet model, which has the SM like coupling of the 125GeV Higgs and the yukawa sector avoiding FCNC, it was shown that the EDM constraints...
We investigate the structure of the Higgs potential in gauge-Higgs unification with a flat extra dimension. As a viable gauge-Higgs unification model, we take the one where the Standard Model Higgs doublet is embedded into a higher-dimensional SU(3)w gauge multiplet and relax five-dimensional Lorentz symmetry. In this model, the deviation in the triple Higgs boson coupling from its SM...
We study the Higgs boson decays h -> c cbar, b bbar, b sbar, photon photon and gluon gluon in the Minimal Supersymmetric Standard Model (MSSM) with general quark flavor violation (QFV), identifying the h with the Higgs boson with a mass of 125 GeV. We compute the widths of the h decays to c cbar, b bbar, b sbar (s bbar) at full one-loop level in the MSSM with QFV. For the h decays to photon...
In the past, homogeneous electromagnetic calorimeters have allowed precision measurements of electrons and photons, while high-granularity, dual-readout, and compensating calorimeters have been considered promising paths for improving hadronic measurements. In this talk, the possibility of using a homogeneous high-granularity crystal electromagnetic calorimeter using SiPMs with a spaghetti...
Jim Brau (U. Oregon), Martin Breidenbach (SLAC), Lorenzo Rota (SLAC), et al.
The SiD Collaboration has had a long interest in the potential for improved granularity in the tracker and ECal; a study of MAPS in the SiD ECal was described in the ILC TDR. Work is progressing on the MAPS application in an upgraded SiD design, both for the ECal and tracking. A prototyping design effort is...
We study search for Right Handed Neutrino at ILC. The process we focus on is the Z′ boson mediated Right Handed neutrino (RHN) pair production process. The advantage of RHN pair production process is back ground free process. In final state, RHN pair production shows the same sign leptons.
We generated this process, investigate event properties, develop reconstruction and selection strategies...
We have fond a relation between the energy deposit and track length in a homogeneous calorimeter situation with GEANT4 at high energy. The relation holds for different materials of the calorimeter from 1 to 100GeV energy range. The energy deposit and track length have a linear relation with positive intercept for both of pions and electrons. The tilt of the straight lines for pion and electron...
The International Large Detector (ILD) is a detector concept for the International Linear Collider (ILC). ILD is a general purpose detector designed to fully reconstruct almost all events. A particular emphasis has been put on excellent jet energy resolution (JER), by optimizing the detector for efficient particle flow reconstruction. Excellent understanding of the absolute jet energy scale...
The origin of tiny neutrino masses, dark matter, and baryon asymmetry of the universe is still a mystery, and there is no doubt that there is new physics beyond the Standard Model. In a previous work, a new physics model at TeV-scale where all of them can be explained has been proposed, however the authors neglected CPV phases, and on the baryon asymmetry, they only showed the possibility of...
Conventional LGADs, of the type to be used in the timing layers of
the upgraded ATLAS and CMS detectors, are unable to provide granularity
finer than the millimeter scale. As a result, a number of
refined approaches are under development to overcome limiting junction
termination requirements and allow for granularity at the 100 um scale
or finer. One such approach, the Deep Junction LGAD,...
We are developing LGAD devices for ILD SiW-ECAL via collaboration with Hamamatsu.
We are testing characteristics of reach-through and inverse-type APDs produced by Hamamatsu with charged particles to estimate gain characteristics and timing resolution. Several test beams have been conducted with sub-GeV positron beam at ELPH, Tohoku University. This talk will cover results with recent test...
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...
One of the physics challenges for new detectors at an e+e- linear collider is to distinguish W and Z vector bosons in their hadronic decay mode. This requires a di-jet mass resolution of the order of the natural width of these bosons and hence a jet energy resolution of about 3%. For hadron calorimetry this means that the required energy resolution be a factor of about two better than...
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 detection layers with scintillator strips ($45~\mathrm{mm} \times 5~\mathrm{mm} \times 2~\mathrm{mm}$ each) coupled to SiPMs are stacked alternately in an orthogonal...
We consider the renormalizable leptophilic WIMP models with the scalar mediators which have lepton numbers. We perform a comprehensive analysis for such a WIMP scenario for two distinct cases with SU(2) doublet or singlet mediators considering all the relevant theoretical, cosmological and experimental constraints at present. We show that mono-photon search at ILC experiment can play a...
During last year, we made significant progress about the material structures that make the fabrication of a DoTPiX pixel and pixel array a reachable goal. The trend is to obtain a small pixel reaching the 1 micrometre x 1 micrometre scale. The structure was simulated as early as 2017 (N. Fourches, IEEE TED 2017) to assess tits electrical and detector capabilities. A work-group was founded with...
We have produced and tested scintillator strips by injection molding method. The newly fabricated scintillator strip stability for ILC scintillator ECAL is studied. Here we report a stability test using beta ray source for more than 3 months. The measured MIP peak position has tendency of gradual change of -0.013%/day.
We have studied the dimple shape for scintillator strips of ILC ECAL....
We study the $S_3$-symmetric two Higgs doublet model by adding two generations of vector like leptons (VLL) which are odd under a discrete $Z_2$-symmetry. The lightest neutral component of the VLL acts as a dark matter (DM) whereas the full VLL set belongs to a dark sector with no mixings allowed with the standard model fermions. We analyse the model in light of dark matter and collider...
The ILC provides an extremely high energy electron beam with an excellent beam divergence. Thus, a linearly polarized photon beam of about 75 GeV can be produced by coherent bremsstrahlung using a thin diamond radiator. Thanks to the electron beam polarization, it is also possible to generate a circularly polarized photon beam. Such a very high energy photon beam would be useful to produce...
The process ee->qq (with q from u to top) plays a central role in the physics programs of high energy electron-positron colliders operating from the O(100GeV) to O(1TeV) center of mass energies. Furthermore, polarised beams as available at the International Linear Collider (ILC) are an essential input for the complete measurement of the helicity amplitudes that govern the production cross...
The International Linear Collider (ILC) will have electron and positron beam energies above 125 GeV. High intensity lasers have achieved unprecedented intensities of $10^{23}$ W/cm$^2$. Although typically such lasers have photons with energies in the eV range in the laboratory frame, colliding such high intensity lasers and the ultrahigh energy electron and positron beams of the ILC will...
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...
Future accelerators like ILC or CLIC are with immense possibilities to improve our understanding of nature's fundamental building blocks and to discover new particles, e.g., WIMPs along with other physics phenomena. In scenarios where dark matter does not or feebly couple with quarks, we can consider the dominant couplings of them with charged leptons. We consider the pair production of...
Conventional muon beams are produced using proton beams and are used in material sciences such as $\mu$SR and elemental analysis, and fundamental physics experiments such as muon g-2 measurements and precision measurements of muoniums. These muon beams have high intensity but poor emittance, and their kinetic energies are $O$(1) MeV. On the other hand, muon beams with a low emittance on the...
Linear Colliders with polarised beams provide unique opportunities to measure the helicity structure of the process ee->qq and to discover the onset of new physics.
This talk presents the status of a detailed simulation study of the process ee->ss based on the ILD concept. Particle identification of final state Kaons plays plays a crucial role for the success of the measurement and will be at...
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 of 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...
In this work, we study the production of color-neutral and singly-charged heavy leptons at the proposed International Linear Collider. We use the optimal observable technique to determine the statistical accuracy to which the coupling of such fermions to the $Z$ gauge boson (vector, axial or chiral) can be measured. We also consider a UV-complete model that contains these particles as well as...
Neutrons are widely used for material sciences, imaging, fundamental physics and so on due to its unique properties. Recently, spallation neutron sources using megawatt class accelerators are coming up as next-generation neutron sources instead of research reactors. A spallation neutron source irradiates proton beam with energy of a few GeV into a neutron spallation target made of a heavy...
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 study of...
The traditional purpose of the ECAL of the ILD experiment is to measure neutrals
(especially photons but also the interacting neutral hadrons) while tracking the
charged particles for particle flow algorithms.
A highly granular Silicon-Tungsten ECAL (SiW-ECAL) is particularly suited for these tasks.
The SiW-ECAL faces many technical challenges: the main ones have been solved,
some...
We confront the Minimal Supersymmetric Standard Model (MSSM) with the recent measurement of (g-2)_mu, the Dark Matter (DM) relic density, DM direct detection limits and electroweak SUSY searches at the LHC. We demonstrate that various distinct regions of the parameter space can fulfil all experimental constraints. We present predictions for the ILC to explore these regions.
Medical RI production is a very promising application of superconducting (SC) linear accelerator. SC LINAC can easily generate large averaged current beam of higher energy than those from industrial electron sources for the electron beam (EB) processing where RI production must be avoided. ILC type long pulsed SC LINAC has great cost efficiency due to low duty factor where RF heat load can...
If nature is supersymmetric and not fine-tuned, higgsinos may well be within the reach of the ILC. In the NMSSM extended with right-handed neutrinos the right-handed sneutrino is a viable thermal dark matter candidate. We discuss how a light higgsino-type chargino could decay to a sneutrino and a charged lepton with a branching ratio O(10^-5). Such a decay will be unobservable at the LHC, but...
The confirmed $(g-2)_\mu$ anomaly can perfectly be fitted in the Minimal Supersymmetric Standard Model (MSSM), taking into account all experimental constraints. This requires a relatively light electroweak sector of the MSSM, which in turn can give rise to positive contributions of the $W$ boson mass, $M_W$. We analyze these predictions in view of the anticipated improved measurements of $M_W$...
In this contribution, we are going to present the last developments on Inverse Low Gain Avalanche Detectors (iLGADs) at IMB-CNM. This 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 on the LGAD technology, the readout is done at the ohmic contacts,...
First we briefly introduce the basic concept of LUXE as an experiment. The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, using the 16.5 GeV electron beam from the European XFEL, aims to probe QED in the non-perturbative regime created in collisions between high-intensity laser pulses and high-energy electron or photon beams. This setup also provides a unique...
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. A large technological prototype has been built and tested in particles beams at DESY and CERN in 2018, and analyses of this data set are well...
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 spin states. The option where dark matter is fermionic is currently one...
The Inert Doublet Model (IDM) is one of the simplest SM extensions and introduces four new scalar particles: H$^\pm$, A and H; the lightest, H, is stable and hence it is a natural dark matter (DM) candidate. A set of benchmark points is considered, which are consistent with current theoretical and experimental constraints and promise detectable signals at future colliders. Discovery reach for...
Picosecond timing measurements have become to one of the hottest topic in the detector development. We are considering to utilize the latest timing measurement technologies to combine with our ILD concept, including application of LGADs to silicon-tungsten ECAL and 100ps-level timing measurements at scintillator calorimeters. The updated detector can be called as "5D particle imaging device"...
Particle Flow Algorithms (PFAs) attempt to measure each particle in a hadronic jet individually, using the component or detector subsystem providing the best energy/momentum resolution. Calorimeters that can fully exploit the power of PFAs emphasize spatial granularity over single particle energy resolution. In this context, the CALICE collaboration developed the Digital Hadron Calorimeter...
The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, using the 16.5 GeV electron beam from the European XFEL, aims to probe QED in the non-perturbative regime created in collisions between high-intensity laser pulses and high-energy electron or photon beams. This setup also provides a unique opportunity to probe physics beyond the standard model by leveraging the large...
We analyze the possible size of various triple Higgs couplings in the 2HDM (type I and II), allowed by all current theoretical and experimental constraints. We discuss how one can get access to them at future $e^+e^-$ with a center-of-mass energy of 500 GeV or more.
An alternative pixel-detector hybridization technology based on Anisotropic Conductive Films (ACF) is under development to replace the conventional fine-pitch flip-chip bump bonding. The new process takes advantage of the recent progress in industrial applications of ACF and is suitable for time- and cost-effective in-house processing of single devices. This new bonding technique developed can...
The International Linear Collider (ILC) is a next-generation electron-positron linear collider proposed to search for new physics beyond the Standard Model.
In the ILC, the International Large Detector (ILD) has been proposed as a detector for the precise measurement of final state particles. Collision of electron and positron generates tau lepton pair in ILC experiment. This process can be...
The FCAL collaboration is preparing large-scale prototypes of special calorimeters to instrument the very forward region at a future electron-positron collider, in particular ILC. The forward region sets challenging requirements on several detector parameters, such as detector compactness, radiation hardness, or ASICs readout parameters. Prototype detector planes assembled with dedicated FE...
We consider an opportunity for beam dump experiments at ILC beam dumps.
Visible decay signatures from new light particles produced in the beam
dumps are considered. Typical sensitivities to new particles for
experimental setups with thick or thin shields are shown.
Models with scalar doublets and charged scalar singlets have the interesting property that they have couplings between one $Z$ boson and two charged scalars of different masses. This property is often ignored in phenomenological analysis, as it is absent from models with only extra scalar doublets. We explore this issue in detail, considering $h \rightarrow Z \gamma$, $B \to X_s \gamma$, and...
One of the most interesting yet-to-be answered questions in Particle Physics is the nature of the Higgs Yukawa couplings and their universality. Key information in our understanding of this question arises from studying the coupling of the Higgs boson to second generation quarks. Some puzzles in the flavor sector and potential additional sources of CP violation could also have their origins in...
The MUonE experiment aims at a competitive determination of the leading hadronic contribution to the muon anomalous magnetic moment, completely independent from the other existing results.
It could have a crucial role to clarify the comparison of the $a_\mu$ measurement with the Standard Model, given the recent Fermilab result, and the tension between the accepted theory prediction and a new...
We analyze the possible realization of a 96 GeV Higgs boson describing the "excesses" observed at CMS in the di-photon decay channel and at LEP in the $b \bar b$ decay channel. We compare the realizations in the 2DMD with an additional real singlet (N2HDM) or a complex singlet (2HDMS). We discuss how these realizations can possibly resolved at future high-energy $e^+e^-$ colliders.
We perform a feasibility study of fixed-target experiments using ILC positron and electron beam dumps. Both visible and invisible decay signatures from new light particles produced in the beam dumps are considered. We show typical sensitivities to new particles for the ILC positron and electron beam dump experiments.
The LHCb vertex detector, VELO, is being upgraded for the LHC Run3. The new hybrid pixel vertex detector will be capable of 40 MHz readout and will be installed in the secondary vacuum of the LHC at a closest proximity of 5.1 mm to the beams during stable collisions. The pixel detector requires a highly thermally efficient and lightweight cooling system. For this purpose a silicon plate...
In the international linear collider (ILC), a high-intense electron beam passes through a helical undulator to produce a multi-MeV circularly polarized photon beam before it is directed to the interaction point (IP). The photon beam hits a thin rotating target to produce electron positron pairs. A maximum active undulator length of 231 m is foreseen to be appropriate for the ILC 250 GeV...
The ILC target materials, Ti-Alloys, radiated at MAMI with a PEDD corresponding to expectations at the ILC, have been analyzed in detail via synchrotron diffraction methods. The methods and the results are discussed in detail in this talk.
Future high energy colliders like the ILC require high intensity positron beams to achieve their targeted high luminosities. The intensity of positron beams is partially defined by the amount of positrons that can be provided by the positron source, which arises from the amount of originally produced positrons and the fraction that can be captured and transported, the so-called yield. In...
The optical matching device (OMD) is responsible for matching the positron beam, produced in the target, according to the damping ring acceptance. This makes the OMD a crucial component for the number of positrons available in the collision experiments. The active plasma lens (APL) is a current-carrying plasma with the potential of being an innovative alternative for traditional OMD concepts...
TBA
The Community Planning Exercise (aka Snowmass), sponsored by the Division of Particles and Fields of the APS, brings together international partners to investigate the state of the field and promising new possibilities for future study. In this talk we will review the current state of the studies described in the Letters of Interest (LoI) submitted for study of the Higgs boson properties with...
TBA
We compute the one-loop corrections to $\sigma(e^+e^-\to Zh)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar SU(2)L representations, we consider the inert doublet, real and complex triplet, quintuplet, and septuplet models. With the sub-percent level precision expected for prospective future $e+e-$ collider measurements of...
Recent direct detection experiments put the strong constraint on WIMPs at the electroweak scale, and people have started focusing on light DM scenario. For the light thermal scalar DM, it is usually constrained by the CMB observation because it annihilate at s-wave. Despite of CMB constraint, We have revealed that some parameter regions are still surviving for the model with singlet scalar...
We demonstrate how probes of CP-violating observables in Higgs di-tau decays at prospective future lepton colliders could provide a test of weak scale baryogenesis with significant discovery potential. Measurements at the Circular Electron Positron Collider, for example, could exclude a CP phase larger than $2.9^\circ$ ($5.6^\circ$) at 68\% (95\%) C.L. assuming the Standard Model value for the...
We discuss the prospect of detecting new gauge bosons (like the dark photon and leptophilic gauge bosons) using the ILC beam dump, assuming that muon shield, veto counter, and particle detector are installed behind the beam dump. Because the $e^\pm$ beams are dumped after each collision at the ILC, a large number of electrons and positrons are available for the beam dump experiment. If a new...
We obtain the upper bound on the new physics scale as a function
of the Higgs coupling deviation factor by considering the perturbative
unitarity of $2\to2$ scattering amplitudes among the longitudinally
polarized electroweak gauge bosons and the Higgs bosons.
We estimate the unitarity bound in a new effective field theory
which parameterizes the sizable non-decoupling effects from...
Fixed target experiments such as NA64 and LDMX use missing energy-momentum to detect the production of dark matter and other long-lived states. The most studied production mechanism is dark Bremsstrahlung through a vector mediator. In this work, we explore a complementary source of missing energy-momentum signals: Bremsstrahlung photons can convert to hard vector mesons in exclusive...
The HEFT is the most general effective field theory with non-linearly realized electroweak symmetry, but it cannot treat the production or decay processes of new particles. In the previous work, we extend the HEFT so that it includes the arbitrary number of neutral and charged scalar fields. In some of the BSM models such as composite Higgs models, however, the SM fermion partners are...
Carbon neutrality by 2050 is one of the most urgent issues in the world, and the ILC aiming to start operation in 2035 should be in line with this global policy. The basic policy of Green ILC activities is not to achieve carbon neutrality within the ILC facility, but to achieve carbon neutrality in the region where the ILC is located. The key to achieving this goal is to cooperate with local...
Precise determination for properties of the Higgs sector is one of the most important issues to clarify physics beyond the SM. For this purpose, we have developed the numerical tool H-COUP, and its version 1 (1-loop calculation for the Higgs boson couplings) and version 2 (1-loop calculation for the Higgs decay rates) have been published. We give a brief review of H-COUP and show how it works...
Higgs couplings to charged leptons forms an important measurement to understand not only the Standard Model but also physics beyond Standard Models including, multihiggs models , supersymmetric models etc. In the present work, We focus on the complementarity between the direct and indirect measurements in fixing the charged Lepton Yukawa couplings including flavour violating couplings. We...
A linear e+e- collider with energy recovery (ERLC) is considered. To avoid parasitic collisions inside the linac a twin LC is proposed. The acceleration gradient is 20 GeV/m, Q=3.10^10. For 2E=250 GeV, the luminosity is about 5.10^35 when working with a duty cycle 1/3 and total power P=130 MW. With the power about 250 MW, it can work in continuous mode and produce L=10^36. This is a “green”...
We consider the next-to-next-to-leading order (NNLO) total cross section of Higgs boson pair production at LHC in the large top quark mass approximation.
At hadron collider, the partonic cross section consists of various initial states such as gluon-gluon, gluon-quark, quark-quark, and we calculated all of them analytically within this approximation.
We found that, in some cases, the...
To generate the baryon asymmetry of the universe, new CP violation sources are needed beyond the Standard Model. We consider a two Higgs doublet model with the CP violation. In this model, the property of the Heavy higgs bosons relevant to the CP phases would be important. We discuss the testability of the model at LHC and ILC.
In Standard Model (SM) Higgs Boson pair production initiated by photons ($\gamma\gamma \to hh$) 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 being an...
In this talk, we will discuss the electroweak first-order phase transition in the Two Higgs Doublet Model. First, we show that an upper bound on the mass of the second Higgs boson can be obtained by combining the sphaleron decoupling condition with perturbative unitarity and vacuum stability. This upper bound is obtained even though the h(125) coupling is standard model-like. Second, we show...
The success of the Belle II experiment at KEK (Japan) relies on the very high instantaneous luminosity, close to 6x10^35 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. The hit rate in the innermost vertex detector layer will exceed 100 MHz/cm2...
We report on studies of the $e^+e^- \to HZ$ process with the subsequent decay of the Higgs boson $H \to Z Z^\star$, where the $Z Z^\star$ combination is reconstructed in the final states with two jets and two leptons. The analysis is performed using Monte Carlo data samples obtained with detailed ILD detector simulation assuming the integrated luminosity 2 ab$^{-1}$, the beam polarizations...
Photon collider (gamma-gamma, gamma-e), PLC, proposed in 1981, was discussed at all LC workshops as a very natural addition to linear e+e-colliders, since the beams are used only once. I will recall the physical motivation and possible parameters of the PLC and what needs to be foreseen in the design of the collider in order to have the PLC in the future (or from the very beginning?).
At the Large Hadron Collider (LHC), several far detectors such as FASER and MATHUSLA have been proposed to target the long-lived particles (LLPs) featured with displaced vertices. Naturally one question arises as to the feasibility of installing similar far detectors at future lepton colliders like the CEPC and FCC-ee. Because of the different kinematics of final state particles and the...
The drive to reduce carbon emissions and reliance on oil and gas has led to the increase in the use of renewable energy heating systems. Ground source heat pump systems are an example of these renewable systems, and tunnels as a way of connecting building heat pump systems to the energy stored in the soil and air. Thermal tunnel energy segments were designed on the Crossrail project, London,...
The CLIC Tracker Detector (CLICTD) is a monolithic CMOS silicon pixel sensor that targets the requirements for the tracking detector of the Compact Linear Collider (CLIC). CLICTD is characterised by a small collection diode that allows for a low sensor capacitance and consequently a high signal-to-noise ratio. The front-end design features an innovative sub-pixel segmentation scheme to reduce...
This talk summarizes a study of realistic design options for a far detector at the Belle II experiment, dubbed GAZELLE. We have quantified the sensitivity of such a detector to long-lived particles produced in e+e- collisions for three benchmark scenarios: axion-like particles, heavy neutral leptons, and a dark matter scenario with a light scalar. GAZELLE will moderately improve the...
A Monolithic CMOS Pixel Sensors (CPS), MIMOSIS, is currently being developed in the TJ-180nm technology by IPHC/IKF/GSI to equip the Micro-Vertex Detector (MVD) of the CBM heavy ion experiment at FAIR/GSI and within the CREMLIN+ program. Thanks to its targeted performances (5 microns spatial resolution/5 micro-second time resolution) MIMOSIS will reach a milestone for the ILC vertex detector...
In many analyses in Higgs, top and electroweak physics, the kinematic reconstruction of the final state is improved by constrained fits. This is a particularly powerful tool at $e^{+}e^{-}$ colliders, where the initial state four-momentum is known and can be employed to constrain the final state. A crucial ingredient to kinematic fitting is an accurate estimate of the measurement...
We consider a gamma-gamma collider with W<12 GeV based on 17 GeV linac of the EU XFEL. High-energy photons will be obtained by Compton scattering of 0.5 μm laser photons on the existing 17.5 GeV electron beams. Such a collider would be an excellent place for the development and application of modern technologies needed for the PLC: powerful lasers, optical cavities and low-emittance electron...
1300MHz Solid State Amplifier that can provide 200kW of 1.6m sec pulse width at 10pps max becomes available with reasonable cost. The latest LDMOS silicon semiconductor devices, NXP's 800W-CW and 1600W-Pk devices, have been implemented and tested successfully.
This amplifier can feed each cavity, which eliminates the complex RF distribution system required for high power Klystrons (MBKs)....
An estimation of detector performance for future particle physics experiments relies both on prototypes tests and on detector simulation quality. Though the most used packages like Geant4 demonstrate quite good agreement, at percent level, for many observables, they are not perfect yet in the description of topological aspects of hadronic shower development, which are important for Particle...
High-voltage CMOS detectors are based on innovative structure where a pixel consists of a single collection electrode with readout electronics placed in it. High-voltage CMOS detectors can be thinned to about 50µm, they have relatively low current consumption and high spatial resolution. Since they are implemented in a commercial CMOS process, the production of large area sensors is...
Potential physical studies feasible with the ILD experiment operating in the e-e- mode at the ILC collider are discussed. A data sample of about 100 fb-1 collected at the e-e- collisions will allow to search for a few specific processes beyond the Standard model. A high sensitivity can be achieved for the processes proceeding through the t-channel exchange of Majorana neutrino, e-e- → W-W-,...
As a postron source at the ILC, it is discussed to use pair creation processes by a $\mathcal{O}(\text{MeV})$ photon beam, which is generated from the high-energy electron beam. The current design expects that the photon flux would be as intense as $10^{17}$ photons / s, being the strongest MeV photon source available on the ground.
We propose to use this photon beam for the search for new...
In the Standard Model（SM）, $h \gamma Z$ 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 3$\sigma$ significance is expected for branching ratio of $h \to \gamma Z$.
On the other hand, $h \gamma Z$ coupling is potentially very sensitive to new...
It is possible to extend the Higgs sector in the Standard Model (SM) of particle physics in various ways, to resolve some of the open problems in the SM. One of the options is the Georgi-Machacek (GM) model, which introduces SU(2) triplet scalars in a non-trivial way. We revisit doubly-charged Higgs boson production processes in the GM model at electron-electron colliders and compare them with...
A monolithic silicon CMOS pixel detector with time-stamping capability (Chronopixel)has been developed based on design goals of the International Linear Collider (ILC). Each hit is accompanied by a time tag with sufficient precision to assign it to a particular ILC bunch crossing - thus the name Chronopixel. This reduces the occupancy to negligible levels, even in the innermost vertex detector...
Though leptoquarks have gained much attention in recent time due to their ability to explain various flavour anomalies, their existence is not confirmed yet experimentally [1]. But, we find that zeros of single photon tree level amplitude [2,3] have the potential to provide information about leptoquarks (if any) at electron-photon collider [4]. It is a well known fact that the tree-level...
In this talk, we discuss whether a multi-step electroweak phase transition (EWPT) occurs in two Higgs doublet models (2HDMs). We examine parameter regions in CP-conserving 2HDMs and find certain areas where the multi-step EWPTs occur. In addition, we compute the Higgs trilinear coupling in the parameter region where the multi-step EWPTs occur, which has the tendency to be large in a certain...
Software tools are foundational for the development of future collider experiments. Detector optimization and physics performance studies crucially depend on the availability of performant and reliable software libraries. The Key4hep project aims at providing infrastructure, interfaces, and a common stack of easy-to-use software tools for future, or even present, High Energy Physics projects....
Experiments at a future 𝑒+𝑒− collider will be able to search for new particles with masses below the nominal centre-of-mass energy by analyzing collisions with initial-state radiation (radiative return). We show that machine learning methods based on semisupervised and weakly supervised learning can achieve model-independent sensitivity to the production of new particles in radiative return...
Using the method of massive operator matrix elements, we calculate the subleading logarithmic QED initial state radiation corrections to the process $e^+ e^- \to \gamma^* / Z^*$ in the limit of large center of mass energies $s \gg m_e^2$ up to $O(\alpha^6)$. We furthermore generalize the calculation to the leading logarithmic corrections to the forward-backward asymmetry to the same order....
A cooling plate has been realized using Aluminum additive manufacturing. It was tested at DESY using a TRACI closed-loop $CO_2$ compressor ensuring a circulation of 2-phase $CO_2$ under a pressure of 60 bars at a temperature of 19 degrees in a Micromegas TPC readout module.
The temperature of the front-end readout cards was continuously monitored for several days using 6 probes. This system...
The Higgs trilinear coupling provides 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. Meanwhile, classical scale invariance (CSI) is an attractive idea for BSM model building, which can explain the apparent alignment of the Higgs sector and potentially relate to the...
A new readout scheme allowing the exploitation of Resistive Plate Chamber (RPC) spatial precision and using a limited number of electronic channels is proposed. The new scheme which exploits the spread of the RPC induced charge on several adjacent inter-connected pads, allows the simultaneous detection of several particles without ambiguity.
In this scheme, pads are connected in rows...
"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...
While QED is a simpler theory than QCD, there are issues related to mass effects and collinear emissions that are specific to higher-order calculations in QED. We discuss our recent approach to tackle these problems, present a first complete NNLO QED calculation for a massive 2->2 process and discuss the impact of these developments on physics at a linear collider.
The Event Data Model (EDM) is at the heart of every HEP experiment software framework. It defines the language physicists can use to express their ideas and also how different software components communicate with each other. The Key4hep project aims to develop a common software stack for all future collider projects. As the common EDM for all these projects, EDM4hep is one of the corner stones...
We studied phenomenological implications of numerous Family Non-Universal U(1)′ sub-models in the minimal U(1)′ extended Supersysmmetric Model (UMSSM) possessing an extra down quark type exotic field. In doing this, we started with anomaly cancellation criteria to generate a number of solutions in which the extra U(1)' charges of the particles are treated as free parameters. We imposed...
We have developed a gaseous pixel detector based on four Timepix3 chips that can serve as a building block for a large detector plane. To provide the required gas amplification a fine grid has been deposited on the chip surface by wafer post-processing (GridPix technology). The precisely aligned grid holes and chip pixels having a pitch of 55 µm and the high time resolution of 1.56 ns of the...
We summarize the status of the multi-purpose event generator Whizard 3 for ILC physics. The focus will be on the UFO interface for BSM models and NLO SM automation. We also cover the top threshold and a few aspects on performance and usage.
In July 2021, we have completed first planned production of the new high statistics 250 GeV MC samples for the ILD physics study using latest generator, simulator, and reconstruction packages.
In this talk, we will summarize the first round of mass production with the summary of produced samples, utilization of ILCDirac, storage occupancy, and the plan of our next production in the ILD.
LHC has produced several indications for new scalars. This talk intends to interpret them within the Georgi Machacek scheme and predict there cross section in e+e-. It follows a presentation delivered at LCWS21 and attemps to complete this presentation showing how the GM model needs to be amplified to take into account the various observations.
References:
[1] Indications for extra...
Extension of the Higgs sector is ubiquitous in physics beyond the Standard Model (BSM), and the two Higgs Doublet Model (2HDM) is one of the simplest extensions containing two scalar doublets instead of one for electroweak symmetry breaking. In the first half of the talk, I will discuss the exclusion limits on the charged Higgs parameter space, $m_{H^\pm}-\tan\beta$, using the CMS results on...
In order to understand the spatial resolution in time direction (z resolution), we are investigating factors that can affect z resolution. Hit position in the z direction is determined by pulse arrival timing and hence depends on the pulse shape. We studied the dependence of the pulse shape on drift distance and magnetic field.
In this talk, we will report the preliminary results from this study.
One of the challenges in times of preparing for a next large-scale collider is to properly model its performance. For physical analyses, event generation of signal and background events is often crucial to estimate discovery reach of the machine for New Physics. In many cases, not only should beam collision background samples be analysed, but also there is a need to include background events...
Blockchain is a technology used to create distributed ledgers and to achieve consensus regarding data between distributed entities. Although the technology has been used to perform extremely computationally calculations involving cryptocurrency, its use in the scientific world has been limited.
In this paper we identify several possible use cases by which blockchain could be applied to...
The experimental observations from the colliders established the standard model (SM), the most successful phenomenological framework to explain the non-gravitational interactions of fundamental particles at high energy. Non-zero neutrino mass and dark matter cast a shadow
over its success. This necessitates the extension of the SM. The most straightforward and elegant extension of the SM to...
Future electron-positron colliders will allow us to test Standard Model physics, especially for the electroweak sector, to an unprecedented level of precision, which could reveal signs for new physics that were previously inaccessible. This requires the theory side to put effort into two aspects. First, we need to link observables predicted by models to the experimental process in a...
While the Higgs boson with the mass of 125GeV was discovered at the LHC experiment, the shape of the Higgs sector remains unknown.
Hence, one can consider various possibilities of extended Higgs models.
The property of the discovered Higgs boson will be precisely measured in future collider experiments such as ILC.
This requires theoretical predictions for the discovered Higgs boson...
It is commonly believed that Dark Matter (DM) should exist in the form of new, Beyond-the-Standard-Model stable particles.
Despite continued efforts, such particles 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...
R&D status of positron production target of E-Driven positron source is presented.
The beam loading compensation on the capture linac of E-Driven positron source is discussed.
System description of E-Driven positron source is summarized including the electron driver, target station, capture linac, positron booster, and ECS.
The Particle Physics Community Planning Exercise ("Snowmass") in the United States aims to identify a strategy for future particle physics in the US and elsewhere. This study includes both the physics cases for experiments and facilities and the technologies that are needed to support such ambitions, including computing. I will discuss the areas under review in the Snowmass computing working...
The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first time, we include LHC data on top production and differential distributions together with Higgs production and decay rates and Simplified Template...
As the heaviest particle of the model, with a mass close to the electroweak scale, the top quark is an interesting candidate to look for hints of new physics. The electroweak couplings of the top quarks are specially relevant in many extensions of the Standard Model. Indeed, as the top quark was not produced in the previous generation of electron-positron colliders most of its electro-weak...
HEP experiments are among the top users at HPC centers worldwide, where they have run in production for years. Significant effort has been invested in adapting HEP workflows to these unique platforms. Yet, we have only scratched the surface. The next generation of exascale HPC systems has the potential to revolutionize HEP computing, but only if we can re-engineer our applications to run in...
We'd like to show the status of quantum computing, in particular, the application to HEP. We'll give a summary of the usage of the supercomputers in the ATLAS experiment and our experience in Japan.
The complementarity of searches for new physics has become increasingly important in recent years, and therefore global analyses of BSM models, including constraints from many sources, are necessary for a full understanding on their validity. In this talk I will describe a global analysis of a model with three right-handed neutrinos using the GAMBIT tool, with constraints from cosmological...
The Belle II computing system is expected to manage the process of massive raw data, production of copious simulation and many concurrent user analysis jobs. To cope with these, we established a distributed computing model with DIRAC as a workload management system and started its operation.
It has been roughly 10 years since we started the Belle II distributed computing activity. In this...
With the completion of the Standard Model, there is no guarantee that new particles can be found at current or future colliders. Meanwhile, precision measurements of the Higgs and electroweak bosons at future lepton colliders offer a great opportunity for probing new physics beyond the Standard Model. The Standard Model Effective Field Theory (SMEFT) provides an ideal framework for a...
We examime models with extended Higgs sectors in the light of recent excesses in the BSM Higgs-boson searches at the LHC. We discuss the possibilities to investigate these scenarios at a future e+e- collider (with a special emphasis on the ILC).
Many new physics scenarios beyond the Standard Model (BSM) often necessitate the existence of new neutral and/or charged scalar fields, which might couple to the SM charged leptons and thus give some BSM signals while evading all existing constraints. We show that future lepton colliders provide a clean environment to probe these BSM including some interesting lepton flavor violating (LFV)...
The LUXE experiment (LASER Und XFEL Experiment) is a new experiment in planning at DESY Hamburg using the electron beam of the European XFEL. LUXE is intended to study collisions between a high-intensity optical laser and 16.5 GeV electrons from the XFEL electron beam, as well as collisions between the optical LASER and high-energy secondary photons. The physics objective of LUXE are processes...
In this talk, recent developments of the design of the Detector Hall and the Assembly Hall will be presented.
