539 research outputs found

    Constraints on Higgs effective couplings in HννˉH\nu \bar{\nu} production of CLIC at 380 GeV

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    The potential of the e+e−→ννˉHe^+e^-\to\nu \bar{\nu} H process in the first stage of CLIC considering center of mass energy of 380 GeV and assuming the baseline integrated luminosity of 500 fb−1^{-1} is examined to probe CP conserving dimension-six operators in a model-independent Standard Model effective field theory framework. In the analysis, a detailed fast simulation on e+e−→ννˉHe^+e^-\to\nu \bar{\nu} H signal processes and dominant backgrounds are performed including parton showering with PYTHIA and detector simulation based on ILD type detector with DELPHES in MadGraph. The obtained best limits on the cˉHB\bar{c}_{HB} , cˉW=−cˉB\bar{c}_{W}=- \bar{c}_{B} and cˉHW\bar{c}_{HW} are [−4.82;1.53]×10−2[-4.82;1.53]\times10^{-2}, [−5.11;4.13]×10−3[-5.11;4.13]\times10^{-3} and [−6.58;5.55]×10−3[-6.58;5.55]\times10^{-3}, respectively.Comment: 13 pages, 6 figures, published versio

    Probing Charged Higgs Boson Couplings at the FCC-hh Collider

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    Many of the new physics models predicts a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at the FCC-hh collider. With an integrated luminosity of 500 fb−1^{-1} at very high energy frontier, we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1 TeV.Comment: 22 pages, 26 figures, 6 table

    Top quark FCNC couplings at future circular hadron electron colliders

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    A study of single top quark production via flavor changing neutral current interactions at tqγtq\gamma vertices is performed at future circular hadron electron collider. The signal cross sections for the processes e−p→e−W±q+Xe^{-}p\to e^{-}W^{\pm}q+X and e−p→e−W±bq+Xe^{-}p\to e^{-}W^{\pm}bq+X in the collision of electron beam with energy Ee=E_e= 60 GeV and proton beam with energy Ep=E_p= 50 TeV are calculated. In the analysis, the invariant mass distributions of three jets reconstructing top quark mass, requiring one b-tagged jet and other two jets reconstructing the WW mass are used to count signal and background events after all selection cuts. The upper limits on the anomalous flavor changing neutral current tqγtq\gamma couplings are found to be λq<\lambda_q < 0.01 at future circular hadron electron collider for Lint=100L_{int}=100 fb−1^{-1} with the fast simulation of detector effects. Signal significance depending on the couplings λq\lambda_q is analyzed and an enhanced sensitivity is found to the branching ratio BR(t→qγt\to q\gamma) at the future circular hadron electron collider when compared to the current experimental results.Comment: 11 pages, 4 Figures, 4 Tables, to appear in Phys. Rev.

    Computer simulation of a pilot in V/STOL aircraft control loops

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    The objective was to develop a computerized adaptive pilot model for the computer model of the research aircraft, the Harrier II AV-8B V/STOL with special emphasis on propulsion control. In fact, two versions of the adaptive pilot are given. The first, simply called the Adaptive Control Model (ACM) of a pilot includes a parameter estimation algorithm for the parameters of the aircraft and an adaption scheme based on the root locus of the poles of the pilot controlled aircraft. The second, called the Optimal Control Model of the pilot (OCM), includes an adaption algorithm and an optimal control algorithm. These computer simulations were developed as a part of the ongoing research program in pilot model simulation supported by NASA Lewis from April 1, 1985 to August 30, 1986 under NASA Grant NAG 3-606 and from September 1, 1986 through November 30, 1988 under NASA Grant NAG 3-729. Once installed, these pilot models permitted the computer simulation of the pilot model to close all of the control loops normally closed by a pilot actually manipulating the control variables. The current version of this has permitted a baseline comparison of various qualitative and quantitative performance indices for propulsion control, the control loops and the work load on the pilot. Actual data for an aircraft flown by a human pilot furnished by NASA was compared to the outputs furnished by the computerized pilot and found to be favorable

    Search for the electromagnetic properties of the neutrinos at the HL-LHC and the FCC-hh

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    The ννˉγγ\nu\bar{\nu}\gamma \gamma couplings parametrized with the non-standard dimension-seven operators defined by the Effective Field Theory framework are investigated through the process pp→ννˉγpp\to \nu\bar{\nu}\gamma at the High Luminosity-LHC and the Future Circular proton-proton Collider. The effective Lagrangian of ννˉγγ\nu\bar{\nu}\gamma \gamma couplings is implemented into FeynRules to generate a UFO module inserted into Madgraph to generate both background and signal events. These events are then passed through Pythia 8 for parton showering and Delphes to include realistic detector effects. The sensitivities on ννˉγγ\nu\bar{\nu}\gamma \gamma couplings are obtained at 95%95\% confidence level. We show that the analysis of the signal emerging from the process pp→ννˉγpp\to \nu\bar{\nu}\gamma allows to improve constraints on ννˉγγ\nu\bar{\nu}\gamma \gamma couplings given by the LEP collaboration.Comment: 14 pages, 6 figures, 2 tables, version accepted for publication in Physics Letters

    Sensitivity of anomalous quartic gauge couplings via tri-photon production at FCC-hh

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    A direct investigation of the self-couplings of gauge bosons, completely described by the non-Abelian gauge symmetry of the Standard Model, is extremely valuable in understanding the gauge structure of the SM. Any deviation from the SM predictions on gauge boson self-coupling is to give a hint at the existence of a new physics beyond the SM, which is defined with a modification of the self-interactions using an effective field theory approach. In this paper, we present a detailed Monte Carlo study searching for anomalous quartic gauge dimension-8 couplings related to γγγγ\gamma\gamma\gamma\gamma and γγγZ\gamma\gamma\gamma Z vertices at the future hadron-hadron collider (FCC-hh) via tri-photon production at a 100 TeV center of mass energy with an integrated luminosity Lint_{int}=30 ab−1^{-1}. Events that have been parton showered and include detector effects are analyzed with a Toolkit for Multivariate Data Analysis (TMVA) using a boosted decision tree to help distinguish between signal and background events to achieve the best sensitivities on anomalous quartic gauge couplings. Our obtained results reveal that the limits on anomalous quartic gauge couplings fT8/Λ4f_{T8}/\Lambda^{4} and fT9/Λ4f_{T9}/\Lambda^{4} at 95\% C.L. without systematic errors are about three orders of magnitude stronger compared to the best current experimental limits reported by the ATLAS collaboration at the LHC. Considering a realistic systematic uncertainty such as 10\% from possible experimental sources, our obtained limits of anomalous quartic couplings get worse by about one order of magnitude compared to those without systematic uncertainty but are still two orders of magnitude better than those recently reported by ATLAS.Comment: 18 pages, 7 figures, some typos corrected and reference adde

    Probing the electromagnetic properties of the neutrinos at future lepton colliders

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    In this study, we explore the non-standard ννˉγγ\nu\bar{\nu}\gamma \gamma couplings parametrized by dimension-seven operators via e+e−→ννˉγe^{+}e^{-} \to \nu\bar{\nu}\gamma process at the FCC-ee/CEPC and μ+μ−→ννˉγ\mu^{+}\mu^{-}\to\nu\bar{\nu}\gamma process at the Muon Colliders. For the detailed Monte Carlo simulation, all signal and relevant background events are produced within the framework of Madgraph where non-standard ννˉγγ\nu\bar{\nu}\gamma \gamma couplings are implemented. After passing through Pythia for parton showering and hadronization, detector effects are included via tuned corresponding detector cards for each collider in Delphes. Projected sensitivities on ννˉγγ\nu\bar{\nu}\gamma \gamma couplings are obtained at a 5σ\sigma confidence level without and with 5%5\% systematic uncertainties for the FCC-ee/CEPC and the Muon Colliders, showcasing the complementarity between lepton colliders. Our best limit on the anomalous ννˉγγ\nu\bar{\nu}\gamma \gamma couplings even with 5\% systematic uncertainties for muon collider with s=10\sqrt{s}=10 TeV and Lint=3L_{int}=3 ab−1^{-1} are found to be thirteen orders of magnitude stronger than the upper bound obtained from rare decay Z→γγννˉZ\to\gamma\gamma\nu\bar{\nu} analysis using LEP data.Comment: 17 pages, 9 figure
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