A geological fence diagram for England and Wales

This report contains a brief description of the data and methodology used to compile the National Geological Fence Diagram (NGFD). The NGFD comprises a network of intersecting geological cross-sections covering England and Wales, to a minimum depth of 1 km and a total section length of approximately 5,500 km. It was compiled by the British Geological Survey (BGS) on behalf of the Environment Agency (EA) and is based upon lines of section agreed between both parties at the inception of the project. The model includes generalised bedrock strata based principally on the BGS 1:625 000 scale digital geological data and superficial deposits greater than 10m in thickness. Additional sources of model data were also considered, largely taken from published BGS data holdings. In total 41 cross-sections were constructed and geologically correlated within the GSI3D software

Community health survey of Oukasie, 1987

A series of surveys were conducted at the request of the community of Oukasie to determine certain public health information in the township, a peri-urban black community. This article describes two of these surveys. The first, a census and partial demographic survey, showed that the total black population was around 6300 with a mean household occupancy of 4,1. Some of the estimated vital statistics calculated were an infant mortality rate of 36,6/1 000, a crude birth rate of 28,0/1 000, a crude death rate of 6,5/1000, and a general fertility rate of 99,3/1 000. The second survey into the nutritional and immunisation status of children aged under 5 years showed that 20% of children were underweight and nearly half were incompletely immunised at 1 year of age. These studies, involving local community and student volunteers, were rapidly and inexpensively done and provide basic public health Information

Measuring environmental health status in Oukasie, 1987

This article reports on some aspects of the physical environment and on envirorvnental health services at Oukasie. The data were collected over a weekend in August 1987 by an interview and by direct inspection of the environment using a standard schedule. We had a 100% response rate on the interviews. There was a mean of 2,2 ± 1,6 persons per room in the households, with brick houses being less crowded than non-brick houses. Private yards were generally kept very clean. Bucket latrines were unhygienic and used by an average of 4 families. No latrine was built to accepted standards. Garbage collection and emptying of the bucket latrines by the municipality seemed to be unsatisfactory. Our overall impression was that where responsibility for maintenance of hygiene is either undefined, such as the collection chambers of bucket latrines, or a responsibility of the public authorities, such as garbage collection and water drainage, there is an unsatisfactory state of hygiene. Where maintenance of cleanlness is clearly a private responsibility, such as the maintenance of the cleanliness of private yards, the general status of hygiene is good

Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene Series: Where and how to look for potential candidates

International audienc

Observation of quantum entanglement with top quarks at the ATLAS detector

Entanglement is a key feature of quantum mechanics with applications in fields such as metrology, cryptography, quantum information and quantum computation. It has been observed in a wide variety of systems and length scales, ranging from the microscopic to the macroscopic. However, entanglement remains largely unexplored at the highest accessible energy scales. Here we report the highest-energy observation of entanglement, in top–antitop quark events produced at the Large Hadron Collider, using a proton–proton collision dataset with a centre-of-mass energy of √s = 13 TeV and an integrated luminosity of 140 inverse femtobarns (fb)−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top–antitop quark production threshold, at which the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from the limitations of the Monte Carlo event generators and the parton shower model in modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for 340 GeV < mtt < 380 GeV. The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far

Study of Z → llγ decays at √s = 8 TeV with the ATLAS detector

This paper presents a study of Z → llγ decays with the ATLAS detector at the Large Hadron Collider. The analysis uses a proton–proton data sample corresponding to an integrated luminosity of 20.2 fb−1 collected at a centre-ofmass energy √s = 8 TeV. Integrated fiducial cross-sections together with normalised differential fiducial cross-sections, sensitive to the kinematics of final-state QED radiation, are obtained. The results are found to be in agreement with stateof-the-art predictions for final-state QED radiation. First measurements of Z → llγ γ decays are also reported

Search for leptoquark pair production decaying into te−te¯ + or tμ−t¯μ+ in multi-lepton final states in pp collisions at √s = 13 TeV with the ATLAS detector

A search for leptoquark pair production decaying into te−te¯ + or tμ−t¯μ+ in final states with multiple leptons is presented. The search is based on a dataset of pp collisions at √s = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. Four signal regions, with the requirement of at least three light leptons (electron or muon) and at least two jets out of which at least one jet is identified as coming from a b-hadron, are considered based on the number of leptons of a given flavour. The main background processes are estimated using dedicated control regions in a simultaneous fit with the signal regions to data. No excess above the Standard Model background prediction is observed and 95% confidence level limits on the production cross section times branching ratio are derived as a function of the leptoquark mass. Under the assumption of exclusive decays into te− (tμ−), the corresponding lower limit on the scalar mixed-generation leptoquark mass mLQd mix is at 1.58 (1.59) TeV and on the vector leptoquark mass mU˜1 at 1.67 (1.67) TeV in the minimal coupling scenario and at 1.95 (1.95) TeV in the Yang–Mills scenario

Measurements of the production cross-section for a Z boson in association with b- or c-jets in proton–proton collisions at √s = 13 TeV with the ATLAS detector

This paper presents a measurement of the production cross-section of a Z boson in association with bor c-jets, in proton–proton collisions at √s = 13 TeV with the ATLAS experiment at the Large Hadron Collider using data corresponding to an integrated luminosity of 140 fb−1. Inclusive and differential cross-sections are measured for events containing a Z boson decaying into electrons or muons and produced in association with at least one b-jet, at least one c-jet, or at least two b-jets with transverse momentum pT > 20 GeV and rapidity |y| < 2.5. Predictions from several Monte Carlo generators based on next-to-leading-order matrix elements interfaced with a parton-shower simulation, with different choices of flavour schemes for initial-state partons, are compared with the measured cross-sections. The results are also compared with novel predictions, based on infrared and collinear safe jet flavour dressing algorithms. Selected Z+ ≥ 1 c-jet observables, optimized for sensitivity to intrinsic-charm, are compared with benchmark models with different intrinsic-charm fractions