We propose a qualitatively new kind of governance for the emerging need to efficiently guide the densely interconnected, ever more complex world development, which is based on explicit and openly presented problem solutions and their interactive implementation practice within the versatile, but unified professional analysis of complex real-world dynamics, involving both the powerful central units and the attached creative worldwide network of professional representatives. We provide fundamental and rigorous scientific arguments in favour of introduction of just that kind of governance (...) at the modern development stage, after the complexity threshold in the real world dynamics evolution (sometimes intuitively designated as "globalisation"), where the traditional spontaneous-empirical kind of development and related administrative governance lose dramatically and inevitably their efficiency and the necessity of explicit consistent understanding and guidance of complex real-world dynamics becomes evident. (shrink)

We review the recently proposed universal concept of dynamic complexity and its new mathematics based on the unreduced interaction problem solution. We then consider its progress-bringing applications at various levels of complex world dynamics, including complex-dynamical nanometal physics and living condensed matter, unreduced nanobiosystem dynamics and the integral medicine concept, causally complete management of complex economical and social dynamics, and the ensuing concept of truly sustainable world governance.

We explain why exactly the simplified abstract scheme of reality within the standard science paradigm cannot provide the consistent picture of “truly fundamental” reality and how the unreduced, causally complete description of the latter is regained within the extended, provably complete solution to arbitrary interaction problem and the ensuing concept of universal dynamic complexity. We emphasize the practical importance of this extension for both particular problem solution and further, now basically unlimited fundamental science development (otherwise dangerously stagnating within its traditional (...) paradigm). (shrink)

Unified and causal complex-dynamic origin of standard (special and general) relativistic and quantum effects revealed previously at the lowest levels of world interaction dynamics is explicitly generalised to all higher levels of unreduced interaction processes, thus additionally confirming the causally complete character of complex-dynamical, naturally quantised relativity, which does not contain any artificially added, abstract postulates. We demonstrate some elementary applications of this generalised quantum relativity at higher levels of complex brain and social interaction dynamics.

Extended Abstract This book introduces and develops a new, universal method of the scientific comprehension of reality providing the objective, ...

Modern fundamental science tends to avoid the principle of physical causality and realism, replacing it with heuristically postulated and separated mathematical constructions that impose their own rules before being adjusted to measurement results. While it is officially accepted as the single possible kind of rigorous knowledge, we argue that another, explicitly extended kind of science can provide the causally complete picture of reality avoiding the glaring gaps, growing problems and persisting stagnation of the artificially reduced knowledge paradigm. The logic of (...) science development and especially its current state call for the urgently needed transition to the extended, causally complete kind of knowledge and related sustainable progress at superior creativity levels of self-aware, reason-based society. (shrink)

While practical efforts in the field of artificial intelligence grow exponentially, the truly scientific and mathematically exact understanding of the underlying phenomena of intelligence and consciousness is still missing in the conventional science framework. The inevitably dominating empirical, trial-and-error approach has vanishing efficiency for those extremely complicated phenomena, ending up in fundamentally limited imitations of intelligent behaviour. We provide the first-principle analysis of unreduced many-body interaction process in the brain revealing its qualitatively new features, which give rise to rigorously defined (...) chaotic, noncomputable, intelligent and conscious behaviour. Based on the obtained universal concepts of unreduced dynamic complexity, intelligence and consciousness, we derive the universal laws of intelligence applicable to any kind of intelligent system interacting with the environment. We finally show why and how these fundamentally substantiated and therefore practically efficient laws of intelligent system dynamics are indispensable for correct AI design and training, which is urgently needed in this time of critical global change towards the truly sustainable development. (shrink)

We show that critically accumulating "difficult" problems, contradictions and stagnation in modern science have the unified and well-specified mathematical origin in the explicit, artificial reduction of any interaction problem solution to an "exact", dynamically single-valued (or unitary) function, while in reality any unreduced interaction development leads to a dynamically multivalued solution describing many incompatible system configurations, or "realisations", that permanently replace one another in causally random order. We obtain thus the universal concept of dynamic complexity and chaos impossible in unitary (...) mathematics. This huge difference between the unreduced mathematics of real-world dynamics and strongly limited unitary “models” of traditional mathematics inevitably induces a growing series of “unsolvable” problems and other “mysteries” that culminate now in the crisis of the “end of science”, where the stagnating unitary “science” in question includes only the described limitation of the traditional mathematical framework (unfortunately accepted as the unique possible basis for any scientific knowledge). In this brief review, we show that science extension to the unreduced, dynamically multivalued mathematics of the intrinsically complex real-world dynamics provides stagnating problem solutions and reconstitution of the intrinsic causality and unity of science desperately missing in its artificially limited unitary framework. Painful stagnation of the latter should be replaced now by the unlimited new progress of the extended, causally complete knowledge of the universal science of complexity, which provides the urgently needed issue from the current impasse of the global civilisation development. (shrink)

The unreduced solution to the arbitrary interaction problem, absent in the standard theory framework, reveals many equally real and mutually incompatible system configurations, or "realizations". This is the essence of universal dynamic undecidability, or multivaluedness, and the ensuing causal randomness (unpredictability), non-computability, irreversible time flow (evolution, emergence), and dynamic complexity of every real system, object, or process. This creative undecidability of real-world dynamics provides causal explanations for "quantum mysteries", relativity postulates, cosmological problems, and the huge efficiency of high-complexity phenomena, such (...) as life, intelligence, and consciousness, giving rise to extended applications, far beyond the critical limits of usual science paradigm. (shrink)

This summary of the original paradigm of the universal science of complexity starts with the discovered exact origin of the stagnating "end" of conventional, unitary science paradigm and development traditionally presented by its own estimates as the only and the best possible kind of scientific knowledge. Using a transparent generalisation of the exact mathematical formalism of arbitrary interaction process, we show that unitary science approach and description, including its imitations of complexity and chaoticity, correspond to artificial and ultimately strong reduction (...) of the natural plurality of unreduced interaction results called realisations to a single, "average" or "exact", realisation. This severe reduction of the natural world dynamics in unitary science underlies all its unsolvable "mysteries" and "paradoxes", persisting "difficult problems", and finally the modern "end" of the progress of just that, actually very special kind of knowledge, whose irreducible limits lead to the modern deep crisis of the global civilisation development. We show then how the rigorously substantiated restoration of the full richness of real-world dynamics within the intrinsically unified knowledge of the universal science of complexity provides not only the causally complete solution to the old and new problems of unitary science but opens practically unlimited possibilities for the new progress of science and civilisation as a result of this crucial extension, which we call complexity revolution. The unreduced analysis of the universal complexity science shows that at the current critical bifurcation point of development, we have only two incompatible possibilities and emerging tendencies, either the dangerously growing degradation within the dominating unitary science and thinking limits (irrespective of purely empirical technology power becoming even dangerous here) or the new golden age of scientific discoveries and civilisation progress with the qualitatively extended approach and results of unreduced complexity science and the new thinking it implies. (shrink)

The unreduced many-body interaction problem solution, absent in usual science framework, reveals a new quality of emerging multiple, equally real but mutually incompatible system configurations, or “realisations”, giving rise to the universal concept of dynamic complexity and chaoticity. Their imitation by a single, “average” realisation or trajectory in usual theory (corresponding to postulated “exact” or perturbative problem solutions) is a rough simplification of reality underlying all stagnating and emerging problems of conventional (unitary) science, often in the form of missing, or (...) “dark”, entities and “hidden variables”. We show how the application of unreduced interaction problem solution and the ensuing concept of dynamic complexity provides the desired causally complete and intrinsically unified solutions to respective unitary science problems in the entire range of complexity levels, from elementary particles and cosmology to emergent consciousness and modern development crisis, implying real, essential and urgently needed progress. (shrink)

The deep crisis in modern fundamental science development is ever more evident and openly recognised now even by mainstream, official science professionals and leaders. By no coincidence, it occurs in parallel to the world civilisation crisis and related global change processes, where the true power of unreduced scientific knowledge is just badly missing as the indispensable and unique tool for the emerging greater problem solution and further progress at a superior level of complex world dynamics. Here we reveal the mathematically (...) exact reason for the crisis in conventional science, containing also the natural and unified problem solution in the form of well-specified extension of usual, artificially restricted paradigm. We show how that extended, now causally complete science content provides various "unsolvable" problem solutions and opens new development possibilities for both science and society, where the former plays the role of the main, direct driver for the latter. We outline the related qualitative changes in science organisation, practice and purposes, giving rise to the sustainability transition in the entire civilisation dynamics towards the well-specified superior level of its unreduced, now well understood and universally defined complexity. (shrink)

An extended analysis compared to observations shows that modern “globalised” world civilisation has passed through the invisible “complexity threshold”, after which usual “spontaneous”, empirically driven kind of development (“invisible hand” etc.) cannot continue any more without major destructive tendencies. A much deeper, non-simplified understanding of real interaction complexity is necessary in order to cope with such globalised world development problems. Here we introduce the universal definition, fundamental origin, and dynamic equations for a major related quantity of (systemic) risk characterising real (...) complex system development tendencies at any level of dynamics. Practically important conclusions are derived, opening further detailed applications in economy, finance and development practice. (shrink)

Instead of postulated fixed structures and abstract principles of usual positivistic science, the unreduced diversity of living world reality is consistently derived as dynamically emerging results of unreduced interaction process development, starting from its simplest configuration of two coupled homogeneous protofields. The dynamically multivalued, or complex and intrinsically chaotic, nature of these real interaction results extends dramatically the artificially reduced, dynamically single-valued projection of standard theory and solves its stagnating old and accumulating new problems, “mysteries” and “paradoxes” within the unified (...) and causally complete picture of intrinsically evolving, dynamically complex reality. The permanently unfolding complexity progress thus revealed is fundamentally unlimited and does not need to stop at the directly observed diversity of usual matter complexity. The exciting, but rigorously substantiated and objectively inevitable prospects of further civilisation complexity development towards its superior levels of genuine sustainability and global Noosphere are outlined, with practically important conclusions for today’s critical problem solution. (shrink)

Critically growing problems of fundamental science organisation and content are analysed with examples from physics and emerging interdisciplinary fields. Their origin is specified and new science structure (organisation and content) is proposed as a unified solution.

A qualitatively new, much more liberal and efficient organisation of science is proposed and justified in connection with emerging international science structures, such as the European Research Council, and growing debates about further role and development of fundamental science. Although the ideas are expressed in terms of "common sense" arguments accessible to a "general" audience, they are based on the rigorous analysis within the recently advanced "universal concept of complexity", which can be applied, due to its universality, also to science (...) structure itself considered as a complex system. We demonstrate thus the application of this ultimate criterion of completeness of a system of knowledge (and viability of related intelligence) that should be able to derive consistent, provable, and practically relevant conclusions about its own purpose, sense, evolution, and current state. (shrink)

Education is essential to life, and the epidemic affected everything. Parents want to get their kids the most important teaching. However, since COVID-19 has affected schools and other institutions, providing education has become the most significant issue. Online learning pedagogy uses technology to provide high-quality learning environments for student-centered learning. Further, this study explores the experiences and challenges faced by Filipino tertiary students regarding the lack of gadgets amidst online learning. Employing the Interpretative Phenomenological Analysis, the findings of this study (...) were: Some college students still have difficulty with online learning. Attending online classes is difficult, especially for students with limited resources. Smartphones, other gadgets, and internet connections play a significant role in online classrooms because they are the ones that students utilize while learning online, which is essential for successful participation in online higher education as well as for solving a variety of other difficulties in the new normal. Further, College students face similar health challenges. Having an online learning setup is not just about students' struggles with learning resources but also about their health issues. When our respondents used their smartphones for an extended period, they reported eye aches and blurred vision. They also said that some of their body parts, such as their legs and back, are aching, and feel pressured because they tend to overthink things in their surroundings, which causes them incredible difficulty in performing their best in attending online classes. Even though college students continue to suffer from a lack of learning resources during online sessions, they do their best to manage their needs and the scarcity of learning resources. Students have unique coping methods for dealing with difficulties in online classes. (shrink)

© 2016, CERN for the benefit of the ATLAS collaboration.The number of charged particles inside jets is a widely used discriminant for identifying the quark or gluon nature of the initiating parton and is sensitive to both the perturbative and non-perturbative components of fragmentation. This paper presents a measurement of the average number of charged particles with >500 pT> 500 {\mathrm{MeV}} MeV inside high-momentum jets in dijet events using 20.3 fb-1 of data recorded with the ATLAS detector in pp collisions (...) at √s = 8 TeV collisions at the LHC. The jets considered have transverse momenta from 50 GeV up to and beyond 1.5 TeV. The reconstructed charged-particle track multiplicity distribution is unfolded to remove distortions from detector effects and the resulting charged-particle multiplicity is compared to several models. Furthermore, quark and gluon jet fractions are used to extract the average charged-particle multiplicity for quark and gluon jets separately. (shrink)

© 2014, CERN for the benefit of the ATLAS collaboration.A search is conducted for non-resonant new phenomena in dielectron and dimuon final states, originating from either contact interactions or large extra spatial dimensions. The LHC 2012 proton–proton collision dataset recorded by the ATLAS detector is used, corresponding to 20 fb at = 8 TeV. The dilepton invariant mass spectrum is a discriminating variable in both searches, with the contact interaction search additionally utilizing the dilepton forward-backward asymmetry. No significant deviations from (...) the Standard Model expectation are observed. Lower limits are set on the contact interaction scale between 15.4 TeV and 26.3 TeV, at the 95 % credibility level. For large extra spatial dimensions, lower limits are set on the string scale between 3.2 TeV to 5.0 TeV. (shrink)

Some philosophers working on the metaphysics of agency argue that if agency is understood in terms of settling the truth of some matters, then the power required for the exercise of intentional agency is an irreducible two-way power to either make it true that p or not-p. In this paper, the focus is on two-way powers in decision-making. Two problems are raised for theories of decision-making that are ontologically committed to irreducible two-way powers. First, recent accounts lack an adequate framework (...) for explaining decisions by the reasons of agents. Second, accepting ontologically irreducible two-way powers into one’s metaphysic of agency implies an ontological commitment to substance dualism. An ontologically less-costly alternative to irreducible two-way powers is offered. It is argued that a reductive account of two-way powers in terms of what George Molnar called “derivative powers” should be accepted. The reductive account can provide us with the truthmakers for talk about two-way powers. Moreover, the reductive account does not share the liabilities of accepting irreducible two-way powers. (shrink)

We prove that for a natural class of first-order formulas the validity problem is Π p 2 -complete.

We use the system of p-adic numbers for the description of information processes. Basic objects of our models are so-called transformers of information, basic processes are information processes and statistics are information statistics (thus we present a model of information reality). The classical and quantum mechanical formalisms on information p-adic spaces are developed. It seems that classical and quantum mechanical models on p-adic information spaces can be applied for the investigation of flows of information in cognitive and social systems, since (...) a p-adic metric gives a quite natural description of the ability to form associations. (shrink)

The problem of doxastic agency concerns what sort of agency humans can exercise with regard to forming doxastic attitudes such as belief. In this essay I defend a version of what James Montmarquet calls "The Asymmetry Thesis": Coming to believe and action are asymmetrical with respect to direct voluntary control. I argue that normal adult human agents cannot exercise direct voluntary control over the acquisition of any of their doxastic attitudes in the same way that they exercise such control over (...) their actions, particularly basic actions. I argue, however, that normal adult human agents can exercise indirect voluntary control over coming to have some of their doxastic attitudes just as they can exercise indirect voluntary control over the outcomes of actions. Furthermore, coming to believe as the outcome of some agency performed with the goal of acquiring a particular doxastic attitude towards a specific proposition can be the intentional outcome of some doxastic agency. So if an agent intends to come to believe that p, under some circumstances she can bring it about that she comes to believe that p as the outcome of her exercise of agency. In critiquing the thesis that agents can exercise direct voluntary control over forming their doxastic attitudes, I argue that some ways of exercising such control are conceptually impossible. But even if other ways of exercising direct voluntary control over the formation of doxastic attitudes are not conceptually impossible, I argue that it is psychologically impossible to exercise direct voluntary control over the acquisition of any doxastic attitudes. I consider proposals offered in defense of the claim that normal adult human agents can exercise direct voluntary control over acquiring doxastic attitudes by Carl Ginet, Mark Heller, Sharon Ryan, and Matthias Steup. I argue that none of the theories of doxastic agency defended by these authors is tenable. So while I argue that the variety of doxastic agency normal adult humans can exercise is fairly robust, the most we can hope for is indirect voluntary control over our doxastic attitudes. (shrink)

© 2017, CERN for the benefit of the ATLAS collaboration.A measurement of the calorimeter response to isolated charged hadrons in the ATLAS detector at the LHC is presented. This measurement is performed with 3.2 nb- 1 of proton–proton collision data at s=7 TeV from 2010 and 0.1 nb- 1 of data at s=8 TeV from 2012. A number of aspects of the calorimeter response to isolated hadrons are explored. After accounting for energy deposited by neutral particles, there is a 5% (...) discrepancy in the modelling, using various sets of Geant4 hadronic physics models, of the calorimeter response to isolated charged hadrons in the central calorimeter region. The description of the response to anti-protons at low momenta is found to be improved with respect to previous analyses. The electromagnetic and hadronic calorimeters are also examined separately, and the detector simulation is found to describe the response in the hadronic calorimeter well. The jet energy scale uncertainty and correlations in scale between jets of different momenta and pseudorapidity are derived based on these studies. The uncertainty is 2–5% for jets with transverse momenta above 2 TeV, where this method provides the jet energy scale uncertainty for ATLAS. (shrink)

© 2016, CERN for the benefit of the.The luminosity determination for the ATLAS detector at the LHC during pp collisions at s= 8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers, and comparisons between these luminosity detectors are made to assess the accuracy, consistency and long-term stability of the results. A luminosity uncertainty of δL/ L= ± 1.9 % is obtained for the 22.7fb-1 of pp collision data delivered to ATLAS at s= (...) 8 TeV in 2012. (shrink)

© 2017, The Author.Differential cross sections are presented for the prompt and non-prompt production of the hidden-charm states X and ψ, in the decay mode J/ψπ+π−, measured using 11.4 fb−1 of pp collisions at s=8 TeV by the ATLAS detector at the LHC. The ratio of cross-sections X/ψ is also given, separately for prompt and non-prompt components, as well as the non-prompt fractions of X and ψ. Assuming independent single effective lifetimes for non-prompt X and ψ production gives RB=ℬ+any)ℬ→J/ψπ+π−)/ℬ+any)ℬ→J/ψπ+π−)=±0.08)×10−2 separating (...) short- and long-lived contributions, assuming that the short-lived component is due to Bc decays, gives RB = ± 0.11) × 10−2, with the fraction of non-prompt X produced via Bc decays for pT) > 10 GeV being ± 2 ± 5)%. The distributions of the dipion invariant mass in the X and ψ decays are also measured and compared to theoretical predictions.[Figure not available: see fulltext.]. (shrink)

© 2017, The Author.Same- and opposite-sign charge asymmetries are measured in lepton+jets tt¯ events in which a b-hadron decays semileptonically to a soft muon, using data corresponding to an integrated luminosity of 20.3 fb−1 from proton-proton collisions at a centre-of-mass energy of s=√8 TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. The charge asymmetries are based on the charge of the lepton from the top-quark decay and the charge of the soft muon from the semileptonic (...) decay of a b-hadron and are measured in a fiducial region corresponding to the experimental acceptance. Four CP asymmetries are measured and are found to be compatible with zero and consistent with the Standard Model.[Figure not available: see fulltext.]. (shrink)

© 2016 The Author.The top quark mass is measured in the tt̄ → dileptonchannel using ATLAS data recorded in the year 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of √s=8 TeV and correspond to an integrated luminosity of about 20.2fb-1. Exploiting the template method, and using the distribution of invariant masses of lepton-b-jetpairs, the top quark mass is measured to be mtop=172.99 ±0.41 ±0.74 GeV, with a total uncertainty of 0.84 GeV. Finally, acombination with (...) previous ATLAS mtop measurements from √s=7TeVdata in the tt̄ → dilepton and tt̄→lepton+jetschannels results in mtop=172.84 ±0.34 ±0.61 GeV, with a total uncertainty of 0.70 GeV. (shrink)

© 2016 The Author.This paper describes a measurement of the inclusive top quark pair production cross-section with a data sample of 3.2 fb−1of proton-proton collisions at a centre-of-mass energy of √s=13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron-muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly (...) two b-tagged jets are counted and used to determine simultaneously σtt̄and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt̄ = 818±8 ± 27 ±19 ± 12 pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented. (shrink)

© 2016 The Author.The production of W±Z events in proton–proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb−1. The W±Z candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons. The measured inclusive cross section in the detector fiducial region for leptonic decay modes is σfid.W±Z→ℓʹ νℓℓ=63.2 ±3.2 ±2.6 ±1.5 fb. In comparison, the next-to-leading-order Standard Model (...) prediction is 53.4+3.6−2.8fb. The extrapolation of the measurement from the fiducial to the total phase space yields σtot.W±Z=50.6 ±2.6 ±2.0 ±0.9 ±1.2 pb, in agreement with a recent next-to-next-to-leading-order calculation of 48.2+1.1−1.0pb. The cross section as a function of jet multiplicity is also measured, together with the charge-dependent W+Z and W−Z cross sections and their ratio. (shrink)

© 2016, CERN for the benefit of the ATLAS collaboration.The dijet production cross section for jets containing a b-hadron has been measured in proton–proton collisions with a centre-of-mass energy of s=7 TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2fb-1. The cross section is measured for events with two identified b-jets with a transverse momentum pT> 20 GeV and a minimum separation in the η–ϕ plane of Δ R= 0.4. At least (...) one of the jets in the event is required to have pT> 270 GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization. (shrink)

© 2016, CERN for the benefit of the ATLAS collaboration.The algorithms used by the ATLAS Collaboration to reconstruct and identify prompt photons are described. Measurements of the photon identification efficiencies are reported, using 4.9 fb- 1 of pp collision data collected at the LHC at s=7 TeV and 20.3 fb- 1 at s=8 TeV. The efficiencies are measured separately for converted and unconverted photons, in four different pseudorapidity regions, for transverse momenta between 10 GeV and 1.5 TeV. The results from (...) the combination of three data-driven techniques are compared to the predictions from a simulation of the detector response, after correcting the electromagnetic shower momenta in the simulation for the average differences observed with respect to data. Data-to-simulation efficiency ratios used as correction factors in physics measurements are determined to account for the small residual efficiency differences. These factors are measured with uncertainties between 0.5% and 10% in 7 TeV data and between 0.5% and 5.6% in 8 TeV data, depending on the photon transverse momentum and pseudorapidity. (shrink)

© 2017, The Author.A measurement of the ZZ production cross section in the ℓ−ℓ+ℓ′ −ℓ′ + and ℓ−ℓ+νν¯ channels in proton-proton collisions at s=8TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for ZZ → ℓ−ℓ+ℓ′ −ℓ′ + and ZZ→ ℓ−ℓ+νν¯ are measured in selected phase-space regions. The total cross section for ZZ events produced with both Z bosons (...) in the mass range 66 to 116 GeV is measured from the combination of the two channels to be 7.3 ± 0.4 ± 0.3− 0.1− 0.2 pb, which is consistent with the Standard Model prediction of 6. 6− 0.6+ 0.7 pb. The differential cross sections in bins of various kinematic variables are presented. The differential event yield as a function of the transverse momentum of the leading Z boson is used to set limits on anomalous neutral triple gauge boson couplings in ZZ production.[Figure not available: see fulltext.]. (shrink)

© 2017, CERN for the benefit of the ATLAS collaboration.The production of two prompt J/ ψ mesons, each with transverse momenta pT> 8.5 GeV and rapidity |y| < 2.1, is studied using a sample of proton-proton collisions at s=8 TeV, corresponding to an integrated luminosity of 11.4 fb- 1 collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised J/ ψ production, is measured as a function of the transverse momentum of the lower-pTJ/ ψ meson, (...) di-J/ ψpT and mass, the difference in rapidity between the two J/ ψ mesons, and the azimuthal angle between the two J/ ψ mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two J/ ψ mesons. The total and double parton scattering cross-sections are compared with predictions. The effective cross-section of double parton scattering is measured to be σeff= 6.3 ± 1.6 ± 1.0 mb. (shrink)

© 2017, The Author.Ratios of top-quark pair to Z-boson cross sections measured from proton-proton collisions at the LHC centre-of-mass energies of s=13 TeV, 8 TeV, and 7 TeV are presented by the ATLAS Collaboration. Single ratios, at a given s for the two processes and at different s for each process, as well as double ratios of the two processes at different s, are evaluated. The ratios are constructed using previously published ATLAS measurements of the tt¯ and Z-boson production cross (...) sections, corrected to a common phase space where required, and a new analysis of Z → ℓ+ℓ− where ℓ = e, μ at s=13 TeV performed with data collected in 2015 with an integrated luminosity of 3.2 fb−1. Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the Z → e+e− and the Z → μ+μ− channels for each s value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-x values near 0.1 and the light-quark sea for x < 0.02.[Figure not available: see fulltext.]. (shrink)

© 2017, The Author.Measurements of top quark spin observables in tt¯ events are presented based on 20.2 fb−1 of s=8 TeV proton-proton collisions recorded with the ATLAS detector at the LHC. The analysis is performed in the dilepton final state, characterised by the presence of two isolated leptons. There are 15 observables, each sensitive to a different coefficient of the spin density matrix of tt¯ production, which are measured independently. Ten of these observables are measured for the first time. All (...) of them are corrected for detector resolution and acceptance effects back to the parton and stable-particle levels. The measured values of the observables at parton level are compared to Standard Model predictions at next-to-leading order in QCD. The corrected distributions at stable-particle level are presented and the means of the distributions are compared to Monte Carlo predictions. No significant deviation from the Standard Model is observed for any observable.[Figure not available: see fulltext.]. (shrink)

© 2017, CERN for the benefit of the ATLAS collaboration.This paper presents a measurement of the polarisation of W bosons from tt¯ decays, reconstructed in events with one high-pT lepton and at least four jets. Data from pp collisions at the LHC were collected at s = 8 TeV and correspond to an integrated luminosity of 20.2 fb- 1. The angle θ∗ between the b-quark from the top quark decay and a direct W boson decay product in the W boson (...) rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ∗ is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F0=0.709±0.019, FL=0.299±0.015 and FR=-0.008±0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the Wtb vertex are set. (shrink)

© 2017 CERN.A measurement of the inclusive pp→tt+X production cross section in the τ+jets final state using only the hadronic decays of the τ lepton is presented. The measurement is performed using 20.2 fb-1 of proton-proton collision data recorded at a center-of-mass energy of s=8 TeV with the ATLAS detector at the Large Hadron Collider. The cross section is measured via a counting experiment by imposing a set of selection criteria on the identification and kinematic variables of the reconstructed particles (...) and jets, and on event kinematic variables and characteristics. The production cross section is measured to be σtt=239±29 pb, which is in agreement with the measurements in other final states and the theoretical predictions at this center-of-mass energy. (shrink)

© 2016, CERN for the benefit of the ATLAS collaboration.The dijet production cross section for jets containing a b-hadron has been measured in proton–proton collisions with a centre-of-mass energy of s=7 TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2fb-1. The cross section is measured for events with two identified b-jets with a transverse momentum pT> 20 GeV and a minimum separation in the η–ϕ plane of Δ R= 0.4. At least (...) one of the jets in the event is required to have pT> 270 GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization. (shrink)

© 2016 The Author.The production of Wboson pairs in association with one jet in pp collisions at √s = 8 TeV is studied using data corresponding to an integrated luminosity of 20.3 fb-1collected by the ATLAS detector during 2012 at the CERN Large Hadron Collider. The cross section is measured in a fiducial phase-space region defined by the presence of exactly one electron and one muon, missing transverse momentum and exactly one jet with a transverse momentum above 25 GeV and (...) a pseudorapidity of |η| <4.5. The leptons are required to have opposite electric charge and to pass transverse momentum and pseudorapidity requirements. The fiducial cross section is found to be σWWfid,1-jet= 136 ± 6 ± 14 ± 3 fb. In combination with a previous measurement restricted to leptonic final states with no associated jets, the fiducial cross section of WW production with zero or one jet is measured to be σWWfid,≤1-jet= 511 ±9 ±26 ±10 fb. The ratio of fiducial cross sections in final states with one and zero jets is determined to be 0.36 ±0.05. Finally, a total cross section extrapolated from the fiducial measurement of WW production with zero or one associated jet is reported. The measurements are compared to theoretical predictions and found in good agreement. (shrink)

© 2016, CERN for the benefit of the ATLAS collaboration.The result of a search for pair production of the supersymmetric partner of the Standard Model bottom quark is reported. The search uses 3.2 fb- 1 of pp collisions at s=13 TeV collected by the ATLAS experiment at the Large Hadron Collider in 2015. Bottom squarks are searched for in events containing large missing transverse momentum and exactly two jets identified as originating from b-quarks. No excess above the expected Standard Model (...) background yield is observed. Exclusion limits at 95 % confidence level on the mass of the bottom squark are derived in phenomenological supersymmetric R-parity-conserving models in which the b~1 is the lightest squark and is assumed to decay exclusively via b~1→bχ~10, where χ~10 is the lightest neutralino. The limits significantly extend previous results; bottom squark masses up to 800 GeV are excluded for the χ~10 mass below 360 GeV whilst differences in mass above 100 GeV between the b~1 and the χ~10 are excluded up to a b~1 mass of 500 GeV. (shrink)

© 2016 The AuthorA search for dark matter pair production in association with a Higgs boson decaying to a pair of bottom quarks is presented, using 3.2 fb−1of pp collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the LHC. The decay of the Higgs boson is reconstructed as a high-momentum bb¯ system with either a pair of small-radius jets, or a single large-radius jet with substructure. The observed data are found to be consistent with (...) the expected backgrounds. Results are interpreted using a simplified model with a Z′gauge boson mediating the interaction between dark matter and the Standard Model as well as a two-Higgs-doublet model containing an additional Z′boson which decays to a Standard Model Higgs boson and a new pseudoscalar Higgs boson, the latter decaying into a pair of dark matter particles. (shrink)

© 2016 The AuthorA search is conducted for both resonant and non-resonant high-mass new phenomena in dielectron and dimuon final states. The search uses 3.2fb−1 of proton–proton collision data, collected at s=13TeV by the ATLAS experiment at the LHC in 2015. The dilepton invariant mass is used as the discriminating variable. No significant deviation from the Standard Model prediction is observed; therefore limits are set on the signal model parameters of interest at 95% credibility level. Upper limits are set on (...) the cross-section times branching ratio for resonances decaying to dileptons, and the limits are converted into lower limits on the resonance mass, ranging between 2.74 TeV and 3.36 TeV, depending on the model. Lower limits on the ℓℓqq contact interaction scale are set between 16.7 TeV and 25.2 TeV, also depending on the model. (shrink)

© 2016 The AuthorA search is conducted for both resonant and non-resonant high-mass new phenomena in dielectron and dimuon final states. The search uses 3.2fb−1 of proton–proton collision data, collected at s=13TeV by the ATLAS experiment at the LHC in 2015. The dilepton invariant mass is used as the discriminating variable. No significant deviation from the Standard Model prediction is observed; therefore limits are set on the signal model parameters of interest at 95% credibility level. Upper limits are set on (...) the cross-section times branching ratio for resonances decaying to dileptons, and the limits are converted into lower limits on the resonance mass, ranging between 2.74 TeV and 3.36 TeV, depending on the model. Lower limits on the ℓℓqq contact interaction scale are set between 16.7 TeV and 25.2 TeV, also depending on the model. (shrink)

© 2016 The AuthorThis Letter presents a search for new resonances with mass larger than 250 GeV, decaying to a Z boson and a photon. The dataset consists of an integrated luminosity of 3.2 fb−1 of pp collisions collected at s=13 TeV with the ATLAS detector at the Large Hadron Collider. The Z bosons are identified through their decays either to charged, light, lepton pairs or to hadrons. The data are found to be consistent with the expected background in the (...) whole mass range investigated and upper limits are set on the production cross section times decay branching ratio to Zγ of a narrow scalar boson with mass between 250 GeV and 2.75 TeV. (shrink)

© 2016, The Author.A search for neutral Higgs bosons of the minimal supersymmetric standard model and for a heavneutral Z′ boson is performed using a data sample corresponding to an integrated luminosity of 3.2 fb- 1 from proton–proton collisions at s=13 TeV recorded by the ATLAS detector at the LHC. The heavy resonance is assumed to decay to a τ+τ- pair with at least one τ lepton decaying to final states with hadrons and a neutrino. The search is performed in (...) the mass range of 0.2–1.2 TeV for the MSSM neutral Higgs bosons and 0.5–2.5 TeV for the heavy neutral Z′ boson. The data are in good agreement with the background predicted by the Standard Model. The results are interpreted in MSSM and Z′ benchmark scenarios. The most stringent constraints on the MSSM mA–tan β space exclude at 95 % confidence level tan β> 7.6 for mA= 200 GeV in the mhmod+ MSSM scenario. For the Sequential Standard Model, a ZSSM′ mass up to 1.90 TeV is excluded at 95 % CL and masses up to 1.82–2.17 TeV are excluded for a ZSFM′ of the strong flavour model. (shrink)

© 2016 The AuthorA search is presented for new resonances decaying to a W or Z boson and a Higgs boson in the ℓ+ℓ−bb¯, ℓνbb¯, and νν¯bb¯ channels in pp collisions at s=13 TeV with the ATLAS detector at the Large Hadron Collider using a total integrated luminosity of 3.2 fb−1. The search is conducted by looking for a localized excess in the WH/ZH invariant or transverse mass distribution. No significant excess is observed, and the results are interpreted in terms (...) of constraints on a simplified model based on a phenomenological Lagrangian of heavy vector triplets. (shrink)

© 2017, CERN for the benefit of the ATLAS collaboration.Two searches for new phenomena in final states containing a same-flavour opposite-sign lepton pair, jets, and large missing transverse momentum are presented. These searches make use of proton–proton collision data, collected during 2015 and 2016 at a centre-of-mass energy s=13 TeV by the ATLAS detector at the large hadron collider, which correspond to an integrated luminosity of 14.7fb-1. Both searches target the pair production of supersymmetric particles, squarks or gluinos, which decay (...) to final states containing a same-flavour opposite-sign lepton pair via one of two mechanisms: a leptonically decaying Z boson in the final state, leading to a peak in the dilepton invariant-mass distribution around the Z boson mass; and decays of neutralinos, yielding a kinematic endpoint in the dilepton invariant-mass spectrum. The data are found to be consistent with the Standard Model expectation. Results are interpreted in simplified models of gluino-pair production, and provide sensitivity to gluinos with masses as large as 1.70 TeV. (shrink)