Measurement of single top-quark production in association with a W boson in the single-lepton channel at \sqrt{s} = 8\,\text {TeV} with the ATLAS detector

The production cross-section of a top quark in association with a W boson is measured using proton–proton collisions at \sqrt{s} = 8\,\text {TeV}. The dataset corresponds to an integrated luminosity of 20.2\,\text {fb}^{-1}, and was collected in 2012 by the ATLAS detector at the Large Hadron Collider at CERN. The analysis is performed in the single-lepton channel. Events are selected by requiring one isolated lepton (electron or muon) and at least three jets. A neural network is trained to separate the tW signal from the dominant t{\bar{t}} background. The cross-section is extracted from a binned profile maximum-likelihood fit to a two-dimensional discriminant built from the neural-network output and the invariant mass of the hadronically decaying W boson. The measured cross-section is \sigma _{tW} = 26 \pm 7\,\text {pb}, in good agreement with the Standard Model expectation

Oral manifestation of cleido cranial displasia

Cleidocranial dysplasia (CCD) is a congenital hereditary condition caused by a dominant autosomal mutation. The orthodontic management of CCD patients is often complicated by the manifestations associated with the condition. The aim of this study was to evaluate the oral manifestations of patients suffering from CCD. The subjects underwent a thorough clinical evaluation that examined both hard and soft tissue. The subjects also underwent an X-ray examination in order to isolate possible anomalies in the stomach region related to the condition. Case 1 presented with a bilateral cross-bite, retention of deciduous teeth, presence of supernumerary teeth and agenesis. Case 2 presented with bilateral cross-bite, retention of deciduous teeth, and the presence of supernumerary teeth. The individuals in this study represent a broad range of typical CCD manifestations and confirm the close correlation between the mutation at CBFA1 level and the presence or oral-dental alterations. An early diagnosis of CCD is essential and based on clinical manifestations, x-ray evidence and genetic tests. Diagnosing the condition can be difficult in cases where there are no evident morphological signs; however, in most cases, an alteration in the rhythm of deciduous tooth loss is immediately apparent, making a closer collaboration between dentists and geneticists fundamental in achieving early diagnosis. As stated above, the timing of the treatment is crucial in establishing a correct course of treatment that involves extractions, orthodontic surgery and the use of prosthetics

Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ -> 4l and ZZ -> 2l2v final states with the ATLAS detector

A measurement of off-shell Higgs boson production in the ZZ -> 4l and ZZ -> 2l2v decay channels, where stands for either an electron or a muon, is performed using data from proton-proton collisions at a centre-of-mass energy of root s = 13 TeV. The data were collected by the ATLAS experiment in 2015 and 2016 at the Large Hadron Collider, and they correspond to an integrated luminosity of 36.1 fb(-1). An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalised to the Standard Model prediction, of 3.8 (3.4) is obtained at 95% confidence level (CL). Assuming the ratio of the Higgs boson couplings to the Standard Model predictions is independent of the momentum transfer of the Higgs production mechanism considered in the analysis, a combination with the on-shell signal-strength measurements yields an observed (expected) 95% CL upper limit on the Higgs boson total width of 14.4 (15.2) MeV. (C) 2018 The Author. Published by Elsevier B.V

Search for heavy ZZ resonances in the l(+) l(-) l(+) l(-) and l(+) l(-) nu(nu)over-bar final states using proton-proton collisions at root s=13 TeV with the ATLAS detector

A search for heavy resonances decaying into a pair of $Z$ bosons leading to $\ell^+\ell^-\ell^+\ell^-$ and $\ell^+\ell^-\nu\bar\nu$ final states, where $\ell$ stands for either an electron or a muon, is presented. The search uses proton proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$ collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 GeV and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin 0 or spin 2 resonance. The upper limits for the spin 0 resonance are translated to exclusion contours in the context of Type I and Type II two-Higgs-doublet models, while those for the spin 2 resonance are used to constrain the Randall Sundrum model with an extra dimension giving rise to spin 2 graviton excitations

Search for heavy ZZ resonances in the +−+− and +−νν¯ final states using proton–proton collisions at √s = 13 TeV with the ATLAS detector

A search for heavy resonances decaying into a pair of Z bosons leading to +−+− and +−νν¯ final states, where stands for either an electron or a muon, is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb−1 collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, while those for the spin-2 resonance are used to constrain the Randall–Sundrum model with an extra dimension giving rise to spin-2 graviton excitations

Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ -> 4l and ZZ -> 2l2v final states with the ATLAS detector

A measurement of off-shell Higgs boson production in the $ZZ\to4\ell$ and $ZZ\to2\ell2\nu$ decay channels, where $\ell$ stands for either an electron or a muon, is performed using data from proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV. The data were collected by the ATLAS experiment in 2015 and 2016 at the Large Hadron Collider, and they correspond to an integrated luminosity of 36.1 fb$^{-1}$. An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalised to the Standard Model prediction, of 3.8 (3.4) is obtained at 95% confidence level (CL). Assuming the ratio of the Higgs boson couplings to the Standard Model predictions is independent of the momentum transfer of the Higgs production mechanism considered in the analysis, a combination with the on-shell signal-strength measurements yields an observed (expected) 95% CL upper limit on the Higgs boson total width of 14.4 (15.2) MeV