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Please see the main conference web pages
http://www.uta.edu/physics/lcws18/index.html
for all information on the program, registration, venue, accommodation.
On-site registration
Dr. Duane Dimos (UTA VP Research)
Dr. Morteza Khaledi (Dean, College of Science)
Dr. Alex Weiss (Chair, UTA Physics)
CMOS Pixel Sensors (CPS) are currently developed for the CBM Micro-Vertex Detector at FAIR/GSI, extrapolating from the ALPIDE
chip fabricated for the ALICE-ITS. The MIMOSIS sensor for CBM will provide resolutions of 5 mum and 5 mus to comply with the CBM requirements and a 50 times higher data flow capacity compared to ALPIDE. Sensors adapted to the ILC requirements are expected to be directly derivable from this chip, with spatial resolution of about 4 mum, read-out time of about 1-2 mus and instantaneous data flow of about few GB/s. This talk will describe the MIMOSIS architecture and the roadmap to adapt it to the ILC requirements. Furthermore, the MIMOSIS-0 sensor, fabricated in 2017 (in the 0.18 mum Tower-Jazz process) has been tested this current year and its results will be shown. Based on this architecture, power consumption estimates of the ILD vertex detector has been reevaluated more precisely and will also be presented. Finally, 2 double sided ladder PLUME have been operated in the BEAST-II infrastructure at superKEKB and were running continuously
from March to July 2018. As a first successful use of CMOS sensors
in an e+e- environment, a feedback experience will be provided.
Future accelerator facilities such as the proposed MaRIE X‐ray Free Electron Laser (XFEL) and compact accelerators for medical applications and National Security would greatly benefit from ultra‐high gradient (UHG) radio‐frequency (RF) accelerating structures. High gradient structures will reduce the construction and operational cost of large facilities and deliver engineering solutions for making compact accelerator systems transportable. Apart from high gradients, some applications need longer pulse durations that are often limited by RF pulse heating in the accelerator structure. This proposal brings together LANL experts from accelerator physics and engineering, metallurgy, and material science to undertake a systematic effort to develop a superior high gradient RF accelerating structure. The areas of research include high gradient cavity shapes (mostly standard nowadays), molecular dynamics modeling of metallic surfaces to study sources of break‐down and potential suppression strategies and fabrication strategies that preserve metallurgic improvements when performing machining or forming. The object of study is a cryo‐cooled copper C‐band resonator.
LANL Publication: LA‐UR‐18‐29159
Chair: Mikael Berggren mikael.berggren@desy.de
How LHC tells us that there is excellent potential for ILC to discover new particles
Data from LHC confirm the existence of a very SM-like Higgs boson
at 125 GeV.
However, it is hard to understand the existence of such a particle
state when its mass is unstable under quantum corrections.
Supersymmetry tames the quantum divergences and the h(125) mass falls
squarely within the narrow SUSY predicted window.
To avoid an unnatural Little Hierarchy within the MSSM,
higgsinos with mass not too far from m(W,Z,h)~100 GeV are required.
Other sparticle contributions to the weak scale are all loop suppressed
and can occur at the several TeV scale with little cost to naturalness.
While light higgsinos are difficult to see at LHC,
they would easily be discovered at ILC with rs>2m(higgsino).
Such light higgsinos are consistent with a SUSY DFSZ solution to the
strong CP problem which also solves the SUSY mu problem and admits a hierarchy
mu<<m(sparticle). Dark matter is expected to be a wimp/axion admixture.
Radiative corrections drive unnatural high scale soft terms to natural
values at the weak scale giving rise to barely broken EW symmetry.
Such a scenario seems to be required by the
string theory landscape which favors large soft terms and a weak scale
not too far from 100 GeV.
Sparticle mass predictions from the landscape are also shown.
-> based on fits in various SUSY frameworks we predict where to find
SUSY at ILC/CLIC.
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 χ ̃±1 ,χ ̃01 and χ ̃02 states can be almost mass degenerate. In this talk the analysis of two benchmark points which exhibits mass difference of O [GeV] in the higgsino sector is presented. Due to their mass degeneracy it is very difficult to observe the decay of such higgsinos at hadron colliders. ILC being an e+e− collider has the prospect of providing very clean physics environment to observe or exclude such scenarios. However, in addition to the desired e+e− → χ ̃+χ ̃− processes, parasitic collisions of real and virtual photons radiated off the e+e− beams occur at the rates depending on the center of mass energy (250 GeV - 1 TeV) and other beam parameters. For instance, at a centre of mass energy 500 GeV the expectation value is about 1.05 γγ events per bunch crossing. In the given higgsino scenarios, visible decay products have low transverse momenta due to their small mass differences. This so called γγ overlay has a very similar topology to our signal event which makes the removal of overlay very challenging. The standard methods to remove γγ background e.g kt algorithm method remains inadequate. This talk presents a proposed solution namely a newly developed track grouping algorithm which is based on the concept of displaced vertices. The algorithm identifies and clusters the tracks from the same origin. The performance of the algorithm is studied through purity checks of clustered tracks and is presented in this talk. We also discuss the scope and the application of this algorithm on the low ∆M higssino analysis.
The DESY II Test Beam Facility is one of few facilities around the world capable of providing multi
GeV particle beams. It is, as such, a key component in current particle detector development including
development of detectors for the International Linear Collider (ILC) .
As part of the AIDA2020 project, a new large area silicon hodoscope has been designed for installa-
tion at the DESY II Test Beam Facility. The sensor used in the hodoscope is based on the Silicon
Detector (SiD) strip tracker which was successfully assembled at DESY. The hodoscope is to be used
as the reference tracker for ongoing measurements of the Linear Collider Time Projection Chamber
Collaboration to determine the achievable momentum resolution of their detector as part of ongoing
research for the International Large Detector (ILD). In this talk, the current state of the hodoscope
system as well as results from the first test beam with the SiD tracker sensor will be provided.
A global review of the design of the laser-beam systems for the ILC polarimeters is made in view of modern and commercially available systems. This review is done in view of robustness of operations and ease of implementation while preserving or improving the required performances of the laser system at the Compton Interaction Point. The challenges related to precise demonstration of per-mille control of the laser-beam circular polarization at the Compton IP will be exposed, since it is one of parameters that will ultimately limit the precision of the polarimeters.
This short talk introduces the session and includes the complete Agenda for the day.
For the International Large Detector (ILD) at the planned International Linear Collider (ILC) a time projection chamber (TPC) is foreseen as the main tracking detector. To achieve the required point resolution, micro pattern gaseous detectors (MPGD) will be used in the amplification stage. A readout module using a stack of three gas electron multipliers (GEM) for gas amplification was
developed at DESY. In a test campaign at the DESY II Test Beam Facility the performance of three of these modules was investigated. This talk will present results on the system’s particle
identification capabilities using the specific energy loss (dE/dx). The results from the prototype were used to extrapolate to the performance of the full ILD TPC, where a dE/dx resolution of better
than 5% could be achieved. In addition, simulation studies were performed to optimize the readout pad size for improved dE/dx separation power. These studies also investigated the possibility to measure the deposited energy by counting the number of ionization clusters (cluster counting). For small enough pads this a pproach was found to give similar or better performance compared to the traditional method of measuring the deposited charge.
Micro Pattern Gaseous Detectors (MPGD)-based TPC is proposed as centraltracker in the ILD for the ILC experiment. As the advantages of MPGD,ExB effect is small and a few millimeter 2-track separation is possiblecompared with MWPC readout. Electron Multipliers (GEM) or Micro-MEshGAseous Structure (Micro MEGAS) are candidate as MPGD-readout technology.Gas detector such as the MPGD has a issue of discharge. We performedthe beam test using a large prototype TPC equipped with readout modulewith double GEM. And the gating foil to suppress ion feedback was set onthe readout module. I report the analysis result including condition ofdischarge.
Chair: Zhen Liu zliuphys@gmail.com
-> full one loop calculations of EW SUSY production
incl. parameter dependence analysis
Once any new particle indicating new physics beyond the SM is discovered at colliders, one of the first crucial steps is to experimentally determine its spin as well as its mass. The future $e^+e^-$ colliders provide perfect tools for studying such properties as long as kinematically accessible, because of the well-constrained event topology and the very clean experimental environment. In this talk, I will demonstrate the strong physics potential of future $e^+e^-$ colliders in mass and spin determination for invisible particles through single-photon processes and antler-topology processes. I will discuss how a set of observables can be designed for determining the spins and chiral structures of the new particles in a rather model-independent way. By exploiting energy- and angular-dependent observables with the help of polarized beams, one can unambiguously determine the spins of invisible particles.
By assuming a dynamical source of CP violation, the tension between sufficient CP violation for successful electroweak baryogenesis and strong constraints from current electric dipole moment measurements could be alleviated. We study how to explore such scenarios through gravitational wave detection, collider experiments, and their possible synergies with a well-studied example.
Chair: Keisuke Fujii keisuke.fujii@kek.jp
In this talk, I will discuss about my recent work on universal relations for the Higgs couplings in composite Higgs models and their phenomenological application for the future lepton colliders. These relations are among one Higgs couplings with two electroweak gauge bosons (HVV), two Higgses couplings with two electroweak gauge bosons (HHVV), one Higgs couplings with three electroweak guage bosons (HVVV), as well as triple gauge boson couplings (TGC). All the universal relations are controlled by a single input parameter: the decay constant f of the pseudo-Nambu- Goldstone Higgs boson.
Recently a method of constructing the non-linear sigma model using only the infrared information is developed. The infrared construction utilizes the unbroken symmetry and the Adler’s zero condition as the only input, resulting in a universal Lagrangian for different symmetry breaking patterns. This implies that the interaction of Higgs bosons in composite Higgs models is universal, where the Higgs bosons act as Nambu-Goldstone bosons resulting from spontaneous symmetry breaking. In this talk I describe how the universal Lagrangian of composite Higgs models is constructed, as well as how such a Lagrangian is gauged
We present a measurement of the CP state of tau lepton pairs produced in Higgs decay using their spin correlations. A precision of 75mrad on the system's CP phase can be obtained using the 2/ab integrated luminosity envisaged for the ILC250 program.
In many models with extended Higgs sectors, e.g. Two Higgs Doublet Model, Next-to-Minimal Supersymmetric Standard Model and Randall Sundrum model, there exists an extra scalar $S$, and the coupling of $SZZ$ can be very small, as expected from the likeness of the 125 GeV Higgs boson measured at the LHC to the SM Higgs boson. Searches for additional scalars at LEP and LHC are usually dependent on the model details, such as decay channels. Thus, it is necessary to have a more general analysis with model-independent assumptions. Furthermore, an extra scalar with suppressed couplings to the $Z$ boson, even when its mass is smaller than 125 GeV, would have still escaped detection at LEP due to its limited luminosity. With a factor of 1000 higher luminosity and polarized beams, the International Linear Collider (ILC) is expected to have substantial discovery potential for such states. In this work, we perform a search for an extra scalar boson produced in association with $Z$ boson at the ILC with a center-of-mass energy of 250 GeV and 500 GeV, using the full Geant4-based simulation of the ILD detector concept. In order to be as model-independent as possible, the analysis is performed using the recoil technique, in particular with the $Z$ boson decaying into a pair of muons. As a preliminary result, exclusion cross-section limits are given in terms of a scale factor k with respect to the Standard Model Higgs-strahlung process cross section. These results, covering all possible searching regions of the extra scalar at the 250 GeV ILC and 500 GeV ILC, can be interpreted independently of the decay modes of the $S$.
Chair: Roberto Franceschini franceschini.roberto@gmail.com
Lepton flavour violation in seesaew models at future lepton colliders ||| The type-II seesaw and its left-right extensions are well-motivated frameworks to understand the tiny neutrino masses. Both the neutral and doubly-charged scalars from these models could couple to the charged leptons in a flavor-changing way, which is intimately related to the neutrino mass generation. A large parameter space of the lepton flavor violating couplings can be probed at future lepton colliders like CLIC, which is well beyond the current low-energy lepton flavor constraints.
We consider the minimal U(1)$_X$ extension of the Standard Model (SM), where three right-handed neutrinos (RHNs) and one SM singlet $U(1)_X$ Higgs field are introduced. The model is anomaly free in the presence of the three RHNs. Associated with the U(1)$_X$ symmetry breaking by the $U(1)_X$ Higgs VEV, the RHNs acquire Majorana masses, and the seesaw mechanism for generating light SM neutrino masses is automatically implemented after the electroweak symmetry breaking. In this talk, I will report our studies on U(1)$_X$ gauge boson signatures at the ILC with a variety of final states, such as a pair of SM fermions and $Z H$. I will also discuss a pair production of RHNs mediated by the U(1)$_X$ gauge boson.
Heavy neutral leptons are part of many extensions of the Standard Model, in particular seesaw models that can explain the light neutrino masses and mixing. Many search strategy have been proposed, either via the direct production of the new heavy neutral leptons or via their indirect effects in processes like lepton flavour violation. We propose here a new search strategy based on WWH production at a linear colider. It is complementary to other observables and would allow to probe the multi-TeV regime with flavour-conserving coupling which is otherwise very challenging to experimentally access
Joint with CFS. See CFS agenda talks.