90 research outputs found

    Scanning spreading resistance microscopy of two-dimensional diffusion of boron implanted in free-standing silicon nanostructures

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    B implants of 1keV, 1×10Âč⁔at.cm⁻ÂČ into 125-nm-wide, free-standing Si nanostructures have been characterized using scanning spreading resistancemicroscopy following a 0s, 1050°Canneal in N₂. A curved diffusion front has been observed. B in the center of the ridge diffuses further than at the sides. A similar effect has been observed in SUPREM-IV simulations. It is attributed to a reduction in transient enhanced diffusion close to the vertical surfaces due to recombination of ion-implantation-induced excess Si self-interstitials

    Measurement of the dependence of transverse energy production at large pseudorapidity on the hard-scattering kinematics of proton-proton collisions at √s=2.76 TeV with ATLAS

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    The relationship between jet production in the central region and the underlying-event activity in a pseudorapidity-separated region is studied in 4.0 pb-1 of s=2.76 TeV pp collision data recorded with the ATLAS detector at the LHC. The underlying event is characterised through measurements of the average value of the sum of the transverse energy at large pseudorapidity downstream of one of the protons, which are reported here as a function of hard-scattering kinematic variables. The hard scattering is characterised by the average transverse momentum and pseudorapidity of the two highest transverse momentum jets in the event. The dijet kinematics are used to estimate, on an event-by-event basis, the scaled longitudinal momenta of the hard-scattered partons in the target and projectile beam-protons moving toward and away from the region measuring transverse energy, respectively. Transverse energy production at large pseudorapidity is observed to decrease with a linear dependence on the longitudinal momentum fraction in the target proton and to depend only weakly on that in the projectile proton. The results are compared to the predictions of various Monte Carlo event generators, which qualitatively reproduce the trends observed in data but generally underpredict the overall level of transverse energy at forward pseudorapidity

    Search for pair-produced resonances decaying to quark pairs in proton-proton collisions at root s=13 TeV

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    A general search for the pair production of resonances, each decaying to two quarks, is reported. The search is conducted separately for heavier resonances (masses above 400 GeV), where each of the four final-state quarks generates a hadronic jet resulting in a four-jet signature, and for lighter resonances (masses between 80 and 400 GeV), where the pair of quarks from each resonance is collimated and reconstructed as a single jet resulting in a two-jet signature. In addition, a b-tagged selection is applied to target resonances with a bottom quark in the final state. The analysis uses data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 35.9 fb(-1), from proton-proton collisions at a center-of-mass energy of 13 TeV. The mass spectra are analyzed for the presence of new resonances, and are found to be consistent with standard model expectations. The results are interpreted in the framework of R-parity-violating supersymmetry assuming the pair production of scalar top quarks decaying via the hadronic coupling lambda ''(312) or lambda ''(323) and upper limits on the cross section as a function of the top squark mass are set. These results probe a wider range of masses than previously explored at the LHC, and extend the top squark mass limits in the (t) over tilde -> qq' scenario.Peer reviewe

    Erratum: Search for Resonant and Nonresonant Higgs Boson Pair Production in the bb[over ÂŻ]τ^{+}τ^{-} Decay Channel in pp Collisions at sqrt[s]=13  TeV with the ATLAS Detector [Phys. Rev. Lett. 121, 191801 (2018)]

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    Measurement of W boson angular distributions in events with high transverse momentum jets at s√= 8 TeV using the ATLAS detector

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    The W boson angular distribution in events with high transverse momentum jets is measured using data collected by the ATLAS experiment from proton–proton collisions at a centre-of-mass energy at the Large Hadron Collider, corresponding to an integrated luminosity of . The focus is on the contributions to processes from real W emission, which is achieved by studying events where a muon is observed close to a high transverse momentum jet. At small angular separations, these contributions are expected to be large. Various theoretical models of this process are compared to the data in terms of the absolute cross-section and the angular distributions of the muon from the leptonic W decay.Fil: Aaboud, M.. UniversitĂ© Mohamed Premier and LPTPM; MarruecosFil: Aad, G.. Aix-Marseille UniversitĂ© ; FranciaFil: Abbott, B.. Oklahoma State University; Estados UnidosFil: Abdallah, J.. Academia Sinica; ChinaFil: Abdinov, O.. Azerbaijan Academy of Sciences; AzerbaiyĂĄnFil: Alconada Verzini, MarĂ­a Josefina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Alonso, Francisco. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Arduh, Francisco Anuar. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Dova, Maria Teresa. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Hoya, JoaquĂ­n. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Monticelli, Fernando Gabriel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Wahlberg, Hernan Pablo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Bossio Sola, Jonathan David. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Marceca, Gino. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Otero y Garzon, Gustavo Javier. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Piegaia, Ricardo Nestor. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Sacerdoti, Sabrina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Zibell. A.. Julius-Maximilians-UniversitĂ€t ; AlemaniaFil: Zieminska, D.. Indiana University; Estados UnidosFil: Zimine, N. I.. Joint Institute for Nuclear Research; RusiaFil: Zimmermann, C.. UniversitĂ€t Mainz ; AlemaniaFil: Zimmermann, S.. Albert-Ludwigs-UniversitĂ€t ; AlemaniaFil: Zinonos, Z.. Georg-August-UniversitĂ€t ; AlemaniaFil: Zinser, M.. UniversitĂ€t Mainz ; AlemaniaFil: Ziolkowski, M.. UniversitĂ€t Siegen ; AlemaniaFil: Ćœivković, L.. University of Belgrade ; SerbiaFil: Zobernig, G.. University of Wisconsin; Estados UnidosFil: Zoccoli, A.. UniversitĂ  di Bologna ; ItaliaFil: Nedden, M. zur. Humboldt University; AlemaniaFil: Zurzolo, G.. UniversitĂ  di Napoli; ItaliaFil: Zwalinski, L.. Cern - European Organization For Nuclear Research; SuizaFil: The ATLAS Collaboration. No especifica

    Operation and performance of the ATLAS Tile Calorimeter in Run 1

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    The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report

    On modeling of logistic overnight in airlines

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    "The present work shows the results of a study that evaluated the overnight operation, using the modeling of air operations where simulation emerges as a tool, consistent with the objective of the organization to achieve better results. The old paradigms air transport issues have worn the new information systems and the need to compensate for supply capacity with demand. Some aviation sector organizations have felt the need to modify their strategic schemes. It is not enough to be part of the market and wait for the opportunities, now, which runs the changes and is innovative in their practices, achieves superior performance in the market. Because of these constant changes, organizations have had to adapt, as in the case of this particular airline, under higher demand stimulated and most comfortable travel plans and innovative, the operations involved in this value chain become more critical, since in the same chain, feels greater dependence and demand in the various logistics operations related to the provision of air service. When viewing this critical chain, there is a need to assess, innovate and improve the most important aspects in the operation.

    TiCl<sub>4</sub>/Et<sub>3</sub>N‑Mediated Condensation of Acetate and Formate Esters: Direct Access to ÎČ‑Alkoxy- and ÎČ‑Aryloxyacrylates

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    A methodology to build (<i>E</i>)-ÎČ-alkoxy- and (<i>E</i>)-ÎČ-aryloxyacrylate moieties from acetate and formate esters promoted by the TiCl<sub>4</sub>/Et<sub>3</sub>N system is presented. The reaction is compatible with a broad range of structural skeletons and elapses through an unusual condensation pathway. Taking into account the obtained results, we propose a plausible mechanism involving a bimetallic titanium intermediate for this type of transformation
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