10,003 research outputs found

    Investigating the Single Production of Vector-Like Quarks Decaying into Top Quark and W Boson through Hadronic Channels at the HL-LHC

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    We investigate the single production of vector-like quarks at the High Luminosity LHC (HL-LHC). With the assumed (enhanced) couplings to third generation quarks of the standard model, vector-like quarks B/XB/X are produced in association with a bottom (bb) or top (tt) quark, which correspond to BbqBbq and Btq/XtqBtq/Xtq production modes, including an additional soft forward jet from the spectator quark (qq). This study focuses on high-mass vector-like quarks B/XB/X decaying into a top quark and a WW boson, resulting in the final state jets emerging from hadronically decaying top quark (tWbt\to Wb) and WW boson (WqqˉW\to q\bar{q}'). The events with WW boson and tt quark have been analysed using tagging techniques for large-radius jets. The scan ranges of the mass (1000<mB<30001000<m_{B}<3000 GeV) for the relative width ΓB/X/mB/X=0.1\Gamma_{B/X}/m_{B/X}=0.1 of vector-like B/XB/X quarks have been investigated. From the results of the analysis, the masses of vector like quarks B (X) up to 2550 (2450) GeV can be excluded at 95%95\% CL depending on the type and branching scenarios at integrated luminosity projection of 33 ab1^{-1} at the HL-LHC.Comment: 18 pages, 5 Tables, 6 Figure

    Obesity Induces Hypothalamic Endoplasmic Reticulum Stress and Impairs Proopiomelanocortin (POMC) Post-translational Processing

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    It was shown previously that abnormal prohormone processing or inactive proconverting enzymes that are responsible for this processing cause profound obesity. Our laboratory demonstrated earlier that in the diet-induced obesity (DIO) state, the appetite-suppressing neuropeptide -melanocyte-stimulating hormone ( -MSH) is reduced, yet the mRNA of its precursor protein proopiomelanocortin (POMC) remained unaltered. It was also shown that the DIO condition promotes the development of endoplasmic reticulum (ER) stress and leptin resistance. In the current study, using an in vivo model combined with in vitro experiments, we demonstrate that obesity-induced ER stress obstructs the post-translational processing of POMC by decreasing proconverting enzyme 2, which catalyzes the conversion of adrenocorticotropin to -MSH, thereby decreasing -MSH peptide production. This novel mechanism of ER stress affecting POMC processing in DIO highlights the importance of ER stress in regulating central energy balance in obesity.Fil: Cakir, Isin. Brown University; Estados UnidosFil: Cyr, Nicole E.. Brown University; Estados UnidosFil: Perello, Mario. Brown University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Litvinov, Bogdan Patedakis. Brown University; Estados UnidosFil: Romero, Amparo. Brown University; Estados UnidosFil: Stuart, Ronald C.. Brown University; Estados UnidosFil: Nillni, Eduardo A.. Brown University; Estados Unido

    Non-Simplified SUSY: Stau-Coannihilation at LHC and ILC

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    If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small stau_1-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states.Comment: 42 pages, 18 figures, 12 table

    Access to improve the muon mass and magnetic moment anomaly via the bound-muon gg factor

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    A theoretical description of the gg factor of a muon bound in a nuclear potential is presented. One-loop self-energy and multi-loop vacuum polarization corrections are calculated, taking into account the interaction with the binding potential exactly. Nuclear effects on the bound-muon gg factor are also evaluated. We put forward the measurement of the bound-muon gg factor via the continuous Stern-Gerlach effect as an independent means to determine the free muons magnetic moment anomaly and mass. The scheme presented enables to increase the accuracy of the mass by more than an order of magnitude

    Evolved model for early fault detection and health tracking in marine diesel engine by means of machine learning techniques

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    The Coast Guard Command, which has a wide range of duties as saving human lives, protecting natural resources, preventing marine pollution and battle against smuggling, uses diesel main engines in its ships, as in other military and commercial ships. It is critical that the main engines operate smoothly at all times so that they can respond quickly while performing their duties, thus enabling fast and early detection of faults and preventing failures that are costly or take longer to repair. The aim of this study is to create and to develop a model based on current data, to select machine learning algorithms and ensemble methods, to develop and explain the most appropriate model for fast and accurate detection of malfunctions that may occur in 4-stroke high-speed diesel engines. Thus, it is aimed to be an exemplary study for a data-based decision support mechanism

    Low dark current and high speed ZnO metal–semiconductor–metal photodetector on SiO2/Si substrate

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    Cataloged from PDF version of article.ZnO thin films are deposited by radio-frequency magnetron sputtering on thermally grown SiO2 on Si substrates. Pt/Au contacts are fabricated by standard photolithography and lift-off in order to form a metal-semiconductor-metal (MSM) photodetector. The dark current of the photodetector is measured as 1 pA at 100V bias, corresponding to 100 pA/cm(2) current density. Spectral photoresponse measurement showed the usual spectral behavior and 0.35 A/W responsivity at a 100V bias. The rise and fall times for the photocurrent are measured as 22 ps and 8 ns, respectively, which are the lowest values to date. Scanning electron microscope image shows high aspect ratio and dense grains indicating high surface area. Low dark current density and high speed response are attributed to high number of recombination centers due to film morphology, deducing from photoluminescence measurements. These results show that as deposited ZnO thin film MSM photodetectors can be used for the applications needed for low light level detection and fast operation. (C) 2014 AIP Publishing LLC

    Theory of the two-loop self-energy correction to the g factor in nonperturbative Coulomb fields

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    Two-loop self-energy corrections to the bound-electron gg factor are investigated theoretically to all orders in the nuclear binding strength parameter ZαZ\alpha. The separation of divergences is performed by dimensional regularization, and the contributing diagrams are regrouped into specific categories to yield finite results. We evaluate numerically the loop-after-loop terms, and the remaining diagrams by treating the Coulomb interaction in the electron propagators up to first order. The results show that such two-loop terms are mandatory to take into account for projected near-future stringent tests of quantum electrodynamics and for the determination of fundamental constants through the gg factor

    Two-loop virtual light-by-light scattering corrections to the bound-electron g factor

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    A critical set of two-loop quantum electrodynamics corrections to the g factor of hydrogenlike ions is calculated in the Furry picture. These corrections are due to the polarization of the external magnetic field by the quantum vacuum, which is dressed by the binding field. The result obtained for the self-energy–magnetic-loop diagrams is compared with the current state-of-the-art result, derived through a perturbative expansion in the binding strength parameter Zα, with Z the atomic number and α the fine-structure constant. Agreement is found in the Z→0 limit. However, even for very light ions, the perturbative result fails to approximate the magnitude of the corresponding correction to the g factor. The total correction to the g factor coming from all diagrams considered in this work is found to be highly relevant for upcoming experimental tests of fundamental physics with highly charged ions

    QED corrections to the g factor of Li- and B-like ions

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    QED corrections to the gg factor of Li-like and B-like ions in a wide range of nuclear charges are presented. Many-electron contributions as well as radiative effects on the one-loop level are calculated. Contributions resulting from the interelectronic interaction, the self-energy effect, and most of the terms of the vacuum-polarization effect are evaluated to all orders in the nuclear coupling strength ZαZ\alpha. Uncertainties resulting from nuclear size effects, numerical computations, and uncalculated effects are discussed
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