This is a comprehensive description of the Enterprise Ontology, a collection of terms and definitions relevant to business enterprises. We state its intended purposes, describe how we went about building it, define all the terms and describe our experiences in converting these into formal definitions. We then describe how we used the Enterprise Ontology and give an evaluation which compares the actual uses with original purposes. We conclude by summarising what we have learned. The Enterprise Ontology was developed within the Enterprise Project, a collaborative effort to provide a framework for enterprise modelling. The ontology was built to serve as a basis for this framework which includes methods and a computer tool set for enterprise modelling. We give an overview of the Enterprise Project, elaborate on the intended use of the ontology, and give a brief overview of the process we went through to build it. The scope of the Enterprise Ontology covers those core concepts required for the project, which will appeal to a wider audience. We present natural language definitions for all the terms, starting with the foundational concepts (e.g. entity, relationship, actor). These are used to define the main body of terms, which are divided into the following subject areas: activities, organisation, strategy and marketing. We review some of the things learned during the formalisation process of converting the natural language definitions into Ontolingua. We identify and propose solutions for what may be general problems occurring in the development of a wide range of ontologies in other domains. We then characterise in general terms the sorts of issues that will be faced when converting an informal ontology into a formal one. Finally, we describe our experiences in using the Enterprise Ontology. We compare these with the intended uses, noting our successes and failures. We conclude with an overall evaluation and summary of what we have learned.

Searches for new resonances decaying into two photons in the ATLAS experiment at the CERN Large Hadron Collider are described. The analysis is based on protonproton collision data corresponding to an integrated luminosity of 3.2 fb −1 at √ s = 13 TeV recorded in 2015. Two searches are performed, one targeted at a spin-2 particle of mass larger than 500 GeV, using Randall-Sundrum graviton states as a benchmark model, and one optimized for a spin-0 particle of mass larger than 200 GeV. Varying both the mass and the decay width, the most significant deviation from the background-only hypothesis is observed at a diphoton invariant mass around 750 GeV with local significances of 3.8 and 3.9 standard deviations in the searches optimized for a spin-2 and spin-0 particle, respectively. The global significances are estimated to be 2.1 standard deviations for both analyses. The consistency between the data collected at 13 TeV and 8 TeV is also evaluated. Limits on the production cross section times branching ratio to two photons for the two resonance types are reported. Conclusion 26The ATLAS collaboration 33 IntroductionNew high-mass states decaying into two photons are predicted in many extensions of the Standard Model (SM). The diphoton final state provides a clean experimental signature with excellent invariant mass resolution and moderate backgrounds. Searches for new high-mass resonances decaying into two photons are described, using CERN Large Hadron Collider (LHC) [1] proton-proton (pp) collision data at √ s= 13 TeV recorded in 2015 by the ATLAS detector. The data correspond to an integrated luminosity of 3.2 fb −1 .The decay photons would have different kinematic properties depending on whether the hypothetical particle has spin-0 or spin-2. These are exploited by applying two different -1 - JHEP09(2016)001selections, with looser kinematic selection requirements for the spin-2 resonance search. The photon identification criteria and the event pre-selection are common to both searches.The search for a spin-2 γγ resonance uses the Randall-Sundrum (RS) model [2] graviton as a benchmark. This entails a lightest spin-2 graviton excitation (G * ) with a dimensionless coupling k/M Pl , where M Pl = M Pl / √ 8π is the reduced Planck scale and k the curvature scale of the extra dimension. The lightest graviton excitation is expected to be a fairly narrow resonance for k/M Pl < 0.3 [4], with the width given by 1.44(k/M Pl ) 2 m G * , where m G * is the mass of the lightest graviton state. For k/M Pl = 0.1, the natural width increases from 11 GeV at m G * = 800 GeV to 30 GeV at m G * = 2200 GeV. For m G * = 800 GeV, the contributions of the natural width and of the experimental mass resolution to the width of the resonance are comparable. The shape of the invariant mass distribution of the main background from the production of prompt photon pairs is estimated from theoretical computations, and the contribution from the reducible background of events where at least one jet is misidentified as a photon is added f...

A measurement of the total pp cross section at the LHC at √ s = 7 TeV is presented. In a special run with high-β beam optics, an integrated luminosity of 80 µb −1 was accumulated in order to measure the differential elastic cross section as a function of the Mandelstam momentum transfer variable t. The measurement is performed with the ALFA sub-detector of ATLAS. Using a fit to the differential elastic cross section in the |t| range from 0.01 GeV 2 to 0.1 GeV 2 to extrapolate to |t| → 0, the total cross section, σ tot (pp → X), is measured via the optical theorem to be:where the first error is statistical, the second accounts for all experimental systematic uncertainties and the last is related to uncertainties in the extrapolation to |t| → 0. In addition, the slope of the elastic cross section at small |t| is determined to be B = 19.73 ± 0.14 (stat.) ± 0.26 (syst.) GeV −2 .

A search is presented for direct top-squark pair production in final states with two leptons (electrons or muons) of opposite charge using 20.3 fb −1 of pp collision data at √ s = 8 TeV, collected by the ATLAS experiment at the Large Hadron Collider in 2012. No excess over the Standard Model expectation is found. The results are interpreted under the separate assumptions (i) that the top squark decays to a b-quark in addition to an on-shell chargino whose decay occurs via a real or virtual W boson, or (ii) that the top squark decays to a t-quark and the lightest neutralino. A top squark with a mass between 150 GeV and 445 GeV decaying to a b-quark and an on-shell chargino is excluded at 95% confidence level for a top squark mass equal to the chargino mass plus 10 GeV, in the case of a 1 GeV lightest neutralino. Top squarks with masses between 215 (90) GeV and 530 (170) GeV decaying to an on-shell (off-shell) t-quark and a neutralino are excluded at 95% confidence level for a 1 GeV neutralino. A Generator-level object and event selection 44 Keywords: Hadron-Hadron ScatteringThe ATLAS collaboration 50 IntroductionSupersymmetry (SUSY) [1][2][3][4][5][6][7][8][9] is an extension to the Standard Model (SM) which introduces supersymmetric partners of the known fermions and bosons. For each known boson or fermion, SUSY introduces a particle with identical quantum numbers except for a difference of half a unit of spin (S). The introduction of gauge-invariant and renormalisable interactions into SUSY models can violate the conservation of baryon number (B) and lepton number (L), resulting in a proton lifetime shorter than current experimental limits [10]. This is usually solved by assuming that the multiplicative quantum number R-parity (R),-1 - JHEP06(2014)124defined as R = (−1) 3(B−L)+2S , is conserved. In the framework of a generic R-parityconserving minimal supersymmetric extension of the SM (MSSM) [11][12][13][14][15], SUSY particles are produced in pairs where the lightest supersymmetric particle (LSP) is stable, and is a candidate for dark matter. In a large variety of models, the LSP is the lightest neutralino (χ 0 1 ). The scalar partners of right-handed and left-handed quarks (squarks),q R andq L , mix to form two mass eigenstates,q 1 andq 2 , withq 1 defined to be the lighter one. In the case of the supersymmetric partner of the top quark (top squark,t), large mixing effects can lead to one top-squark mass eigenstate,t 1 , that is significantly lighter than the other squarks. Consideration of naturalness and its impact on the SUSY particle spectrum, suggests that top squarks cannot be too heavy, to keep the Higgs boson mass close to the electroweak scale [16,17]. Thust 1 could be pair-produced with relatively large cross-sections at the Large Hadron Collider (LHC).The top squark can decay into a variety of final states, depending, amongst other factors, on the hierarchy of the mass eigenstates formed from the linear superposition of the SUSY partners of the Higgs boson and electroweak gauge bosons. I...

This article presents measurements of the t-channel single top-quark (t) and top-antiquark (t) total production cross sections σðtqÞ and σðtqÞ, their ratio R t ¼ σðtqÞ=σðtqÞ, and a measurement of the inclusive production cross section σðtq þtqÞ in proton-proton collisions at ffiffi ffi s p ¼ 7 TeV at the LHC. Differential cross sections for the tq andtq processes are measured as a function of the transverse momentum and the absolute value of the rapidity of t andt, respectively. The analyzed data set was recorded with the ATLAS detector and corresponds to an integrated luminosity of 4.59 fb −1 . Selected events contain one charged lepton, large missing transverse momentum, and two or three jets. The cross sections are measured by performing a binned maximum-likelihood fit to the output distributions of neural networks. The resulting measurements are σðtqÞ ¼ 46 AE 1ðstatÞ AE 6ðsystÞ pb, σðtqÞ ¼ 23 AE 1ðstatÞ AE 3ðsystÞ pb, R t ¼ 2.04 AE 0.13ðstatÞ AE 0.12ðsystÞ, and σðtq þtqÞ ¼ 68 AE 2ðstatÞ AE 8ðsystÞ pb, consistent with the Standard Model expectation. The uncertainty on the measured cross sections is dominated by systematic uncertainties, while the uncertainty on R t is mainly statistical. Using the ratio of σðtq þtqÞ to its theoretical prediction, and assuming that the top-quark-related CKM matrix elements obey the relation jV tb j ≫ jV ts j; jV td j, we determine jV tb j ¼ 1.02 AE 0.07.