Publications by authors named "I P J Shipsey"
A search for the exclusive hadronic decays W^{±}→π^{±}γ, W^{±}→K^{±}γ, and W^{±}→ρ^{±}γ is performed using up to 140 fb^{-1} of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of sqrt[s]=13 TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products.
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- - The ATLAS experiment at the LHC conducted a search for long-lived particles (LLPs) using a large dataset (140 fb^{-1}) from proton-proton collisions at 13 TeV, focusing on LLPs with masses from 5 to 55 GeV that decay within the inner detector.
- - The study considered scenarios where LLPs are produced from exotic Higgs boson decays and models involving axionlike particles (ALPs).
- - No significant findings above expected background levels were detected, leading to the establishment of upper limits on various production rates involving the Higgs boson and the top quark related to LLPs and ALPs.
Article Synopsis
- The study investigates the associated production of Higgs and W bosons, focusing on how the relative signs of the Higgs couplings to W and Z bosons impact the process.
- Two specific searches were conducted using large amounts of collision data from the LHC to analyze different coupling scenarios: one for opposite-sign couplings and another for same-sign (standard model-like) couplings.
- The results significantly exclude the opposite-sign coupling hypothesis and set a strict upper limit on the production rate of this process compared to standard model predictions.
This Letter presents results from a combination of searches for Higgs boson pair production using 126-140 fb^{-1} of proton-proton collision data at sqrt[s]=13 TeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.
View Article and Find Full Text PDFThis Letter presents the first study of the energy dependence of diboson polarization fractions in WZ→ℓνℓ^{'}ℓ^{'}(ℓ,ℓ^{'}=e,μ) production. The dataset used corresponds to an integrated luminosity of 140 fb^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally polarized bosons are defined.
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