Search for lepton flavour violation in the eμ continuum with the ATLAS detector in √s = 7 TeV pp collisions at the LHC

This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark (t) in the e^± μ^∓ continuum using 2.1 fb^(−1) of data collected by the ATLAS detector in √s = 7 TeV pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95 % C.L. are calculated as a function of the scalar top mass (mt). The upper limits on the production cross section for pp → eμX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for m_t=95 GeV to 30 fb for m_t=1000 GeV

A search for tt resonances with the ATLAS detector in 2.05 fb^(−1) of proton-proton collisions at √s =7 TeV

A search for top quark pair resonances in final states containing at least one electron or muon has been performed with the ATLAS experiment at the CERN Large Hadron Collider. The search uses a data sample corresponding to an integrated luminosity of 2.05 fb^(−1), which was recorded in 2011 at a proton-proton centre-of-mass energy of 7 TeV. No evidence for a resonance is found and limits are set on the production cross-section times branching ratio to tt for narrow and wide resonances. For narrow Z′ bosons, the observed 95 % Bayesian credibility level limits range from 9.3 pb to 0.95 pb for masses in the range of m_(Z′)=500 GeV to m_(Z′)=1300 GeV. The corresponding excluded mass region for a leptophobic topcolour Z′ boson (Kaluza-Klein gluon excitation in the Randall-Sundrum model) is m_(Z′)<880 GeV (m_(gKK)< 1130 GeV)

Measurement of dijet production with a veto on additional central jet activity in pp collisions at √s = 7TeV using the ATLAS detector

A measurement of jet activity in the rapidity interval bounded by a dijet system is presented. Events are vetoed if a jet with transverse momentum greater than 20 GeV is found between the two boundary jets. The fraction of dijet events that survive the jet veto is presented for boundary jets that are separated by up to six units of rapidity and with mean transverse momentum 50 < p_T < 500 GeV. The mean multiplicity of jets above the veto scale in the rapidity interval bounded by the dijet system is also presented as an alternative method for quantifying perturbative QCD emission. The data are compared to a next-to-leading order plus parton shower prediction from the powheg-box, an all-order resummation using the hej calculation and the pythia, herwig++ and alpgen event generators. The measurement was performed using pp collisions at √s=7 TeV using data recorded by the ATLAS detector in 2010

Measurement of the inclusive jet cross-section in pp collisions at √s = 2.76 TeV and comparison to the inclusive jet cross-section at √s = 7 TeV using the ATLAS detector

The inclusive jet cross-section has been measured in proton–proton collisions at √s = 2.76 TeV in a dataset corresponding to an integrated luminosity of 0.20^(-1) collected with the ATLAS detector at the Large Hadron Collider in 2011. Jets are identified using the anti-k_t algorithm with two radius parameters of 0.4 and 0.6. The inclusive jet double-differential cross-section is presented as a function of the jet transverse momentum p_T and jet rapidity y, covering a range of 20≤p_T<430 GeV and |y|<4.4. The ratio of the cross-section to the inclusive jet cross-section measurement at √s = 7 TeV , published by the ATLAS Collaboration, is calculated as a function of both transverse momentum and the dimensionless quantity x_T =2 p_T/√s, in bins of jet rapidity. The systematic uncertainties on the ratios are significantly reduced due to the cancellation of correlated uncertainties in the two measurements. Results are compared to the prediction from next-to-leading order perturbative QCD calculations corrected for non-perturbative effects, and next-to-leading order Monte Carlo simulation. Furthermore, the ATLAS jet cross-section measurements at √s = 2.76 TeV and √s = 7 TeV are analysed within a framework of next-to-leading order perturbative QCD calculations to determine parton distribution functions of the proton, taking into account the correlations between the measurements

Ultrasound investigation of the fetal cerebral ventricles

Peer Reviewe

Measurement of the tt production cross section in the tau + jets channel using the ATLAS detector

A measurement of the top quark pair production cross section in the final state with a hadronically decaying tau lepton and jets is presented. The analysis is based on proton–proton collision data recorded by the ATLAS experiment at the LHC, with a centre-of-mass energy of 7 TeV. The data sample corresponds to an integrated luminosity of 1.67 fb^(−1). The cross section is measured to be σ_(tt)=194±18 (stat.)±46 (syst.) pb and is in agreement with other measurements and with the Standard Model prediction

Search for a light charged Higgs boson in the decay channel H^+→cs in tt events using pp collisions at s√=7 TeV with the ATLAS detector

A search for a charged Higgs boson (H^+) in tt decays is presented, where one of the top quarks decays via t→H^+ b, followed by H^+→ two jets (cs). The other top quark decays to Wb, where the W boson then decays into a lepton (e/μ) and a neutrino. The data were recorded in pp collisions at s√=7 TeV by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.7 fb^(−1). With no observation of a signal, 95 % confidence level (CL) upper limits are set on the decay branching ratio of top quarks to charged Higgs bosons varying between 5 % and 1 % for H^+ masses between 90 GeV and 150 GeV, assuming B(H^+→cs)=100%

Multi-channel search for squarks and gluinos in √s = 7 TeV pp collisions with the ATLAS detector at the LHC

A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb^(−1) of s√=7 TeV pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry. Mutually exclusive final states are defined, allowing a combination of all channels to increase the search sensitivity. No deviation from the Standard Model expectation is observed. Upper limits at 95 % confidence level on visible cross-sections for the production of new particles are extracted. Results are interpreted in the context of the constrained minimal supersymmetric extension to the Standard Model and in supersymmetry-inspired models with diverse, high-multiplicity final states

Solar energy research and development program on the exploitation of the solar resource on the Reunion Island and its integration into an electrical power grid

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.Reunion Island stands out by its specific energy context due to its growing population and a strong economic development. The main objective of this French region is to ensure that its exceptional potential for renewable power generation could meet an increasing energy demand. Regarding the energy development, the Regional strategy is to reach the energy independence by 2030 (SPL “Energies Réunion”) without using fossil fuels. In this context, the LE2P is leading a solar resource research programme with the aim to use solar resource as a stable source of energy and ensure its management in a reliable and efficient way for its integration into an electrical power grid. This paper aims to describe the methodology used for the development of this ambitious and challenging R&D program, projects articulation within the LE2P roadmap’s and the collaborations and partnerships initiated in UE and OI zone, permitting Eco city development especially in the IO area.cf201

Transcriptional response to cardiac injury in the zebrafish: systematic identification of genes with highly concordant activity across in vivo models

Background: Zebrafish is a clinically-relevant model of heart regeneration. Unlike mammals, it has a remarkable heart repair capacity after injury, and promises novel translational applications. Amputation and cryoinjury models are key research tools for understanding injury response and regeneration in vivo. An understanding of the transcriptional responses following injury is needed to identify key players of heart tissue repair, as well as potential targets for boosting this property in humans. Results: We investigated amputation and cryoinjury in vivo models of heart damage in the zebrafish through unbiased, integrative analyses of independent molecular datasets. To detect genes with potential biological roles, we derived computational prediction models with microarray data from heart amputation experiments. We focused on a top-ranked set of genes highly activated in the early post-injury stage, whose activity was further verified in independent microarray datasets. Next, we performed independent validations of expression responses with qPCR in a cryoinjury model. Across in vivo models, the top candidates showed highly concordant responses at 1 and 3 days post-injury, which highlights the predictive power of our analysis strategies and the possible biological relevance of these genes. Top candidates are significantly involved in cell fate specification and differentiation, and include heart failure markers such as periostin, as well as potential new targets for heart regeneration. For example, ptgis and ca2 were overexpressed, while usp2a, a regulator of the p53 pathway, was down-regulated in our in vivo models. Interestingly, a high activity of ptgis and ca2 has been previously observed in failing hearts from rats and humans. Conclusions: We identified genes with potential critical roles in the response to cardiac damage in the zebrafish. Their transcriptional activities are reproducible in different in vivo models of cardiac injury. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-852) contains supplementary material, which is available to authorized users