EPS-HEP2017

Abstracts

Electroweak precision measurements at CLIC

• Speaker: Matthias Weber (CERN)
• Status: Accepted for poster presentation (id 400)
• Track: Top and Electroweak Physics
• Abstract: The Compact Linear Collider (CLIC) is an option for a future electron-positron collider operating at centre-of-mass energies from a few hundred GeV up to 3 TeV. Following an overview of precision electroweak measurements possible at a high-energy electron-positron collider like CLIC, details will be presented on two recent physics benchmark analyses based on full detector simulations and assuming centre-of-mass energies of 1.4 and 3 TeV. Vector boson scattering gives insight into the mechanism of electroweak symmetry breaking. The processes e+e- -> WWvv and e+e- -> ZZvv were studied using fully hadronic events which provide the full kinematic information on the final-state bosons. The expected precisions on anomalous gauge couplings are extracted. The process e+e- -> gammagamma allows to search for deviations from QED. The expected sensitivities to a finite electron size and other scenarios are discussed.
• Poster

Higgs and BSM physics at CLIC

• Speaker: Gordana Milutinovic-Dumbelovic (Vinca Institute)
• Status: Accepted for parallel talk (id 401)
• Track: Higgs and New Physics
• Abstract: The Compact Linear Collider (CLIC) is an option for a future electron-positron collider operating at centre-of-mass energies from a few hundred GeV up to 3 TeV. This contribution discusses the Higgs and BSM physics reach of CLIC operating in several energy stages. The presented results are based on physics benchmark analyses using full detector simulations, several of which have been completed recently. The initial stage of operation near the top quark pair production threshold allows to study Higgs boson production in the Higgsstrahlung and WW-fusion processes, resulting in model-independent determinations of the Higgs couplings. High-energy operation, here assumed at 1.4 and 3 TeV, gives access to rarer Higgs decays and production processes such as double Higgs production, which is sensitive to the Higgs self-coupling. In the second part of the presentation, examples for direct and indirect new physics searches are given. In both cases, the achievable sensitivities generally rise with the centre-of-mass energy.
• Slides

The CLIC detector

• Speaker: Matthias Weber (CERN)
• Status: Accepted for parallel talk (id 402)
• Track: Detector R&D and Data Handling
• Abstract: The proposed Compact Linear Collider (CLIC) will provide electron-positron collisions with centre-of-mass energy operation in three stages from a few hundred GeV up to 3 TeV. This offers a rich precision physics program combined with high sensitivity to a wide range of possible new phenomena. The precision required for such measurements and the specific conditions imposed by the beam bunch sizes and time structure put strict requirements on the detector design and technology development. This includes ultra-low mass vertexing and tracking systems with small cells, highly granular imaging calorimeters, and a precise hit-timing resolution for all subsystems. A new optimised detector model matching these requirements has been integrated in the CLIC simulation framework. A variety of detector optimisation studies have been carried out to establish the overall detector performance and to assess the impact of different technology options. In parallel, ambitious R&D programs, e.g. for silicon tracking detectors, are pursued, addressing the challenging detector requirements with innovative new technologies. This contribution reviews the optimisation studies performed for critical parameters of the CLIC detector, presents the detector performance achieved in full-detector simulations and gives an overview of the ongoing hardware R&D.
• Slides

Toward Precision Top Quark Measurements in e+e- collisions at Linear Colliders

• Speaker: Naomi van der Kolk (Max-Planck-Institute for Physics)
• Status: Joint abstract with ILC/LCC, Accepted for parallel talk
• Track: Top and Electroweak Physics
• Abstract: This talk presents a review of precision top quark measurements at linear e+e- colliders, with results from the ILC detector concepts and the CLIC detector and physics group. After a brief overview of established elements of the top physics programme, the contribution focuses on new developments in the full-simulation studies of key measurements. These include improvements in the experimental strategies for top quark pair production in the continuum, both at 380-500 GeV and at high energy where top quarks are highly boosted. New results are presented on the potential of a linear collider to measure the top electro-weak couplings, where the precision on the CP-violating dipole moment has been evaluated in full simulation for the first time. The study into the potential of the top quark mass measurement at threshold is updated, including a thorough evaluation of theoretical uncertainties. New results on the reach of searches for rare flavour-changing neutral current decays are presented as well.
• Slides