Search for Heavy Top-like Quarks t' -> Wq Using Lepton Plus Jets Events in 1.96 TeV Proton-Antiproton Collisions

We present the results of a search for pair production of a new heavy top-like quark t' decaying to a W boson and another quark using the CDF II detector in Run II of the Tevatron proton-antiproton collider. Using a data sample corresponding to 760 pb^-1 of integrated luminosity, we fit the observed spectrum of total transverse energy and reconstructed t' quark mass to a combination of standard model processes and t' pair production. We see no evidence for t' pair production, and we infer a lower limit of 256 GeV/c^2 on the mass of the t' at 95% C.L. assuming standard strong couplings for the t'.Comment: 7 pages, 2 figure

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

High Frequency, High Efficiency, and High Power Density GaN-Based LLC Resonant Converter: State-of-the-Art and Perspectives

Soft switching for both primary and secondary side devices is available by using LLC converters. This resonant converter is an ideal candidate for today&rsquo;s high frequency, high efficiency, and high power density applications like adapters, Uninterrupted Power Supplies (UPS), Solid State Transformers (SST), electric vehicle battery chargers, renewable energy systems, servers, and telecom systems. Using Gallium-Nitride (GaN)-based power switches in this converter merits more and more switching frequency, power density, and efficiency. Therefore, the present paper focused on GaN-based LLC resonant converters. The converter structure, operation regions, design steps, and drive system are described precisely. Then its losses are discussed, and the magnets and inductance characteristics are investigated. After that, various interleaved topologies, as a solution to improve power density and decrease current ripples, have been discussed. Also, some challenges and concerns related to GaN-based LLC converters have been reviewed. Commercially available power transistors based on various technologies, i.e., GaN HEMT, Silicon (Si) MOSFET, and Silicon Carbide (SiC) have been compared. Finally, the LLC resonant converter has been simulated by taking advantage of LTspice and GaN HEMT merits, as compared with Si MOSFETs

iMPACT: An Innovative Tracker and Calorimeter for Proton Computed Tomography

This contribution describes the first results obtained within the iMPACT project, which aims to build a novel proton computed-tomography (pCT) scanner for protons of energy up to 230 MeV, as used in hadron therapy. The iMPACT pCT scanner will improve the current state-of-the-art in proton tracking at all levels: speed, spatial resolution, material budget, and cost. We will first describe the design of the iMPACT scanner, which is composed by a tracker and a range calorimeter. We will then illustrate the results of a test with the ALPIDE sensor, a monolithic active pixels sensor, developed by the ALICE collaboration, which will equip the iMPACT tracker in this first phase. We finally detail the characterization building elements of the prototype of the range calorimeter, which is composed of segmented scintillator fingers readout by SiPMs. Reported beam-test data will highlight how the technological choices we made well address the performances of a state-of-the-art pCT system

Emile Driant/Capitaine Danrit. La warfiction francese tra revanche ed orientalismo

Emile Driant/Capitaine Danrit. La warfiction francese tra revanche ed orientalism

Direct measurement of the W boson width in p(p)over-bar collisions at root s=1.96 TeV

A direct measurement of the total decay width of the W boson Gamma(W) is presented using 350 pb(-1) of data from p (p) over bar collisions at root s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230 185 W candidates decaying to e nu and mu nu in the transverse-mass region 50 < M(T) < 90 GeV and then fitting the predicted shape to 6055 events in the high-M(T) region, 90 < M(T) < 200 GeV. The result is Gamma(W) = 2032 +/- 45(stat) +/- 57(syst) MeV, consistent with the standard model expectation