276 research outputs found

    Planning and Logistics Issues raised by the Individual System Tests during the Installation of the LHC

    Get PDF
    The running of individual system tests has to fit within tight constraints of the LHC installation planning and of CERN's accelerator activity in general. For instance, the short circuit tests of the power converters that are performed in-situ restrict the possibility to work in neighbouring areas; much in the same way, the cold tests of the cryogenic distribution line involve safety access restrictions that are not compatible with the transport and installation of cryo-magnets or interconnect activities in the sector considered. Still, these individual system tests correspond to milestones that are required to insure that we can continue with the installation of machine elements. This paper reviews the conditions required to perform the individual system tests and describe how the general LHC installation planning is organised to allocate periods for these tests

    Differential cross-sections for events with missing transverse momentum and jets measured with the ATLAS detector in 13 TeV proton-proton collisions

    Get PDF

    Measurement of vector boson production cross sections and their ratios using pp collisions at s=13.6 TeV with the ATLAS detector

    Get PDF

    Search for heavy Majorana neutrinos in e±e± and e±μ± final states via WW scattering in pp collisions at s=13 TeV with the ATLAS detector

    Get PDF

    Measurement of ZZ production cross-sections in the four-lepton final state in pp collisions at √s = 13.6 TeV with the ATLAS experiment

    Get PDF

    Search for Nearly Mass-Degenerate Higgsinos Using Low-Momentum Mildly Displaced Tracks in pp Collisions at sqrt(s)=13 TeV with the ATLAS Detector

    Get PDF

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and −0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Search for heavy neutral Higgs bosons decaying into a top quark pair in 140 fb−1 of proton-proton collision data at s \sqrt{s} = 13 TeV with the ATLAS detector

    Get PDF

    Search for the Exclusive W Boson Hadronic Decays W±→π±γ , W±→K±γ and W±→ρ±γ with the ATLAS Detector

    Get PDF

    Search for non-resonant Higgs boson pair production in the 2b+2l+ETmiss final state in pp collisions at s = 13 TeV with the ATLAS detector

    Get PDF
    A search for non-resonant Higgs boson pair (HH) production is presented, in which one of the Higgs bosons decays to a b-quark pair (bb ̄) and the other decays to WW*, ZZ*, or τ+τ−, with in each case a final state with l+l−+ neutrinos (l = e, μ). The analysis targets separately the gluon-gluon fusion and vector boson fusion production modes. Data recorded by the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb−1, are used in this analysis. Events are selected to have exactly two b-tagged jets and two leptons with opposite electric charge and missing transverse momentum in the final state. These events are classified using multivariate analysis algorithms to separate the HH events from other Standard Model processes. No evidence of the signal is found. The observed (expected) upper limit on the cross-section for non-resonant Higgs boson pair production is determined to be 9.7 (16.2) times the Standard Model prediction at 95% confidence level. The Higgs boson self-interaction coupling parameter κλ and the quadrilinear coupling parameter κ2V are each separately constrained by this analysis to be within the ranges [−6.2, 13.3] and [−0.17, 2.4], respectively, at 95% confidence level, when all other parameters are fixed
    corecore