2,562 research outputs found

    ATLAS Muon Spectrometer

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    The muon spectrometer of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN was designed to achieve a momentum resolution of better than 10% at 1 TeV. It consists of three superconducting air-core toroid magnets instrumented with three layers of precision drift chambers and dedicated fast trigger chambers. During the commissioning of the full ATLAS detector in the last year several 100 millions of events of cosmic ray data were recorded. We will report on the status and our experience with the muon precision tracking and trigger chambers, the level-1 trigger, and the spectrometer alignment. The global performance of the muon system will be discussed. The readiness of the ATLAS muon spectrometer for first collisions will be demonstrated

    Topological Higgs inflation: The origin of the Standard Model criticality

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    The measured values of the Higgs and top masses and of the strong gauge coupling constant point to the near-criticality of the Standard Model, where two vacua at the electroweak and Planck scales are quasi-degenerate. We argue that the criticality is required by the occurrence of an eternal topological inflation induced by the Higgs potential. The role of this inflation is to continuously create sufficiently flat and homogeneous Universe, providing the necessary initial condition for the subsequent slow-roll inflation that generates the density perturbations of the right magnitude. While the condition for the topological Higgs inflation is only marginally satisfied in the Standard Model, it can be readily satisfied if one introduces the right-handed neutrinos and/or the non-minimal coupling to gravity; currently unknown quantum gravity corrections to the potential may also help. We also discuss the BLB-L Higgs inflation as a possible origin of the observed density perturbations. Its necessary initial condition, the restored BLB-L symmetry, can be naturally realized by the preceding topological Higgs inflation.Comment: 13 pages, 2 figures; Version to appear on PRD(v2

    Interactively Picking Real-World Objects with Unconstrained Spoken Language Instructions

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    Comprehension of spoken natural language is an essential component for robots to communicate with human effectively. However, handling unconstrained spoken instructions is challenging due to (1) complex structures including a wide variety of expressions used in spoken language and (2) inherent ambiguity in interpretation of human instructions. In this paper, we propose the first comprehensive system that can handle unconstrained spoken language and is able to effectively resolve ambiguity in spoken instructions. Specifically, we integrate deep-learning-based object detection together with natural language processing technologies to handle unconstrained spoken instructions, and propose a method for robots to resolve instruction ambiguity through dialogue. Through our experiments on both a simulated environment as well as a physical industrial robot arm, we demonstrate the ability of our system to understand natural instructions from human operators effectively, and how higher success rates of the object picking task can be achieved through an interactive clarification process.Comment: 9 pages. International Conference on Robotics and Automation (ICRA) 2018. Accompanying videos are available at the following links: https://youtu.be/_Uyv1XIUqhk (the system submitted to ICRA-2018) and http://youtu.be/DGJazkyw0Ws (with improvements after ICRA-2018 submission

    The cross-correlation search for a hot spot of gravitational waves : Numerical study for point spread function

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    The cross-correlation search for gravitational wave, which is known as 'radiometry', has been previously applied to map of the gravitational wave stochastic background in the sky and also to target on gravitational wave from rotating neutron stars/pulsars. We consider the Virgo cluster where may be appear as `hot spot' spanning few pixels in the sky in radiometry analysis. Our results show that sufficient signal to noise ratio can be accumulated with integration times of the order of a year. We also construct numerical simulation of radiometry analysis, assuming current constructing/upgrading ground-based detectors. Point spread function of the injected sources are confirmed by numerical test. Typical resolution of radiometry analysis is a few square degree which corresponds to several thousand pixels of sky mapping.Comment: 9 pages, 9 figures, Amaldi 9 & NRD