Search for s-channel single top-quark production in proton-proton collisions at s√=8 TeV with the ATLAS detector

This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb−1. Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single top-quark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of σs=5.0±4.3 pb, consistent with the Standard Model expectation.

Search for the Xb and other hidden-beauty states in the π+π-ϒ{hooked}(1S) channel at ATLAS

This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges 10.05--10.31 GeV and 10.40--11.00 GeV, in the channel Xb→π+π−Υ(1S)(→μ+μ−), using 16.2 fb−1 of s√=8 TeV pp collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the Υ(2S), at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the Υ(13DJ), Υ(10860), and Υ(11020) states also reveal no significant signals.

Search for W'→tb- in the lepton plus jets final state in proton-proton collisions at a centre-of-mass energy of s=8 TeV with the ATLAS detector

A search for new charged massive gauge bosons, called W′, is performed with the ATLAS detector at the LHC, in proton--proton collisions at a centre-of-mass energy of s√ = 8 TeV, using a dataset corresponding to an integrated luminosity of 20.3 fb−1. This analysis searches for W′ bosons in the W′→tb¯ decay channel in final states with electrons or muons, using a multivariate method based on boosted decision trees. The search covers masses between 0.5 and 3.0 TeV, for right-handed or left-handed W′ bosons. No significant deviation from the Standard Model expectation is observed and limits are set on the W′→tb¯ cross-section times branching ratio and on the W′-boson effective couplings as a function of the W′-boson mass using the CLs procedure. For a left-handed (right-handed) W′ boson, masses below 1.70 (1.92) TeV are excluded at 95% confidence level.

Simultaneous measurements of the tt¯, W+W−, and Z/γ∗→ττ production cross-sections in pp collisions at s√=7 TeV with the ATLAS detector

Simultaneous measurements of the tt¯, W+W−, and Z/γ∗→ττ production cross-sections using an integrated luminosity of 4.6 fb−1 of pp collisions at s√=7 TeV collected by the ATLAS detector at the LHC are presented. Events are selected with two high transverse momentum leptons consisting of an oppositely charged electron and muon pair. The three processes are separated using the distributions of the missing transverse momentum of events with zero and greater than zero jet multiplicities. Measurements of the fiducial cross-section are presented along with results that quantify for the first time the underlying correlations in the predicted and measured cross-sections due to proton parton distribution functions. These results indicate that the correlated NLO predictions for tt¯ and Z/γ∗→ττ significantly underestimate the data, while those at NNLO generally describe the data well. The full cross-sections are measured to be σ(tt¯)=181.2±2.8+9.7−9.5±3.3±3.3 pb, σ(W+W−)=53.3±2.7+7.3−8.0±1.0±0.5 pb, and σ(Z/γ∗→ττ)=1174±24+72−87±21±9 pb, where the cited uncertainties are due to statistics, systematic effects, luminosity and the LHC beam energy measurement, respectively.

Measurement of charged-particle spectra in Pb+Pb collisions at √sNN = 2.76TeV with the ATLAS detector at the LHC

Charged-particle spectra obtained in 0.15nb−1 of Pb+Pb interactions at sNN−−−√=2.76TeV and 4.2pb−1 of pp interactions at s√=2.76TeV with the ATLAS detector at the LHC are presented in a wide transverse momentum (0.5

Measurement of the forward-backward asymmetry of electron and muon pair-production in pp collisions at s√ = 7 TeV with the ATLAS detector

This paper presents measurements from the ATLAS experiment of the forward-backward asymmetry in the reaction pp→Z/γ∗→l+l−, with l being electrons or muons, and the extraction of the effective weak mixing angle. The results are based on the full set of data collected in 2011 in pp collisions at the LHC at s√ = 7 TeV, corresponding to an integrated luminosity of 4.8 fb−1. The measured asymmetry values are found to be in agreement with the corresponding Standard Model predictions. The combination of the muon and electron channels yields a value of the effective weak mixing angle of 0.2308±0.0005(stat.)±0.0006(syst.)±0.0009(PDF), where the first uncertainty corresponds to data statistics, the second to systematic effects and the third to knowledge of the parton density functions. This result agrees with the current world average from the Particle Data Group fit.

Measurement of the production of neighbouring jets in lead-lead collisions at √sNN=2.76 TeV with the ATLAS detector

This Letter presents measurements of correlated production of nearby jets in Pb+Pb collisions at sNN−−−√=2.76 TeV using the ATLAS detector at the Large Hadron Collider. The measurement was performed using 0.14 nb−1 of data recorded in 2011. The production of correlated jet pairs was quantified using the rate, RΔR, of ``neighbouring'' jets that accompany ``test'' jets within a given range of angular distance, ΔR, in the pseudorapidity--azimuthal angle plane. The jets were measured in the ATLAS calorimeter and were reconstructed using the anti-kt algorithm with radius parameters d=0.2, 0.3, and 0.4. RΔR was measured in different Pb+Pb collision centrality bins, characterized by the total transverse energy measured in the forward calorimeters. A centrality dependence of RΔR is observed for all three jet radii with RΔR found to be lower in central collisions than in peripheral collisions. The ratios formed by the RΔR values in different centrality bins and the values in the 40--80 % centrality bin are presented.

Two-particle Bose–Einstein correlations in pp collisions at s√= 0.9 and 7 TeV measured with the ATLAS detector

The paper presents studies of Bose--Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range pT> 100 MeV and |η|< 2.5 in proton--proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. The integrated luminosities are approximately 7 μb−1, 190 μb−1 and 12.4 nb−1 for 0.9 TeV, 7 TeV minimum-bias and 7 TeV high-multiplicity data samples, respectively. The multiplicity dependence of the BEC parameters characterizing the correlation strength and the correlation source size are investigated for charged-particle multiplicities of up to 240. A saturation effect in the multiplicity dependence of the correlation source size is observed using the high-multiplicity 7 TeV data sample. The dependence of the BEC parameters on the average transverse momentum of the particle pair is also investigated.

Preditores de viabilidade em pacientes com resposta negativa à ecocardiografia de estresse com dobutamina de baixa dose

FUNDAMENTO: A ecocardiografia de estresse com dobutamina de baixa dose é um teste específico para predizer disfunção de contratilidade reversível, mas mesmo assim, sua sensibilidade é menor do que ideal. OBJETIVO: Avaliar os preditores de recuperação miocárdica contrátil após a revascularização, em pacientes sem viabilidade na ecocardiografia de estresse com dobutamina de baixa dose. MÉTODOS: Trinta pacientes consecutivos foram selecionados consecutivamente, que apresentavam estenose coronária/oclusão significantes, tratáveis através de revascularização, anormalidade de motilidade de parede regional na distribuição da artéria afetada e ausência de viabilidade na ecocardiografia de estresse com dobutamina de baixa dose. Os pacientes foram submetidos a estudo de imagem com 99mTc-sestamibi em repouso e então submetidos à revascularização coronária bem sucedida. A ecocardiografia de seguimento foi realizada três meses depois. Os pacientes foram classificados em 2 grupos: grupo 1: com evidência de recuperação miocárdica contrátil após a revascularização na ecocardiografia de seguimento e grupo 2: sem evidência de recuperação miocárdica. Os dois grupos foram comparados em relação aos dados clínicos, ecocardiográficos e cintilográficos. RESULTADOS: A média da idade era 52,3 ± 5,9 anos e 97% eram do sexo masculino. A porcentagem de captação total de 99mTc-sestamibi foi significantemente mais alta no grupo 1 quando comparado ao grupo 2 (p < 0,01) e foi o preditor independente mais forte de recuperação miocárdica contrátil no seguimento de 3 meses na análise de regressão multivariada. A curva ROC (Receiver Operating Characteristic) mostrou que um valor de corte da porcentagem de captação total do 99mTc-sestamibi uptake de 72%, foi o melhor preditor da recuperação miocárdica contrátil, com uma sensibilidade de 100% e especificidade de 95.7%. CONCLUSÃO: Em pacientes sem evidência de viabilidade na ecocardiografia de estresse com dobutamina de baixa dose, a porcentagem de captação total do 99mTc-sestamibi prediz, de forma independente, a recuperação miocárdica contrátil após a revascularização coronária.

Leptina e aldosterona na atividade simpática na hipertensão resistente, com ou sem Diabetes Tipo 2

FUNDAMENTO: A descoberta da leptina como um estimulador da atividade simpática trouxe uma nova perspectiva para os mecanismos fisiopatológicos da obesidade-hipertensão. OBJETIVO: Avaliamos a relação entre a atividade simpática aumentada e as concentrações plasmáticas de leptina e aldosterona em Hipertensos Resistentes (HR), comparando os grupos com e sem Diabetes Tipo 2 (DT2). MÉTODOS: Vinte e cinco pacientes HR foram avaliados por eletrocardiografia ambulatorial para análise da Variabilidade da Frequência Cardíaca (VFC) nos domínios do tempo e frequência, os quais foram estratificados em dois períodos: 24 horas e período Diurno (D), compreendendo as medidas entre 14 e 18h (domínio do tempo) e uma hora às 15h (domínio da frequência). RESULTADOS: O grupo DT2 (n = 10) apresentou maiores concentrações de aldosterona e leptina que o grupo não DT2 (n = 15) (26,0 ± 11,5 vs. 16,9 ± 7,0 ng/dL - p = 0,021; 81,368.7 ± 47,086.1 vs. 41,228.1 ± 24,523.1 pg/mL - p = 0,048, respectivamente). Houve correlação entre aldosterona e VFC no domínio da frequência em ambos os grupos. Não-DT2 apresentaram a aldosterona correlacionada com D baixa frequência em unidades normalizadas (BFnu) (r = 0,6 [0,12 - 0,85] p = 0,018) e D alta frequência em unidades normalizadas (AFnu) (r = -0,6 [-0,85 - -0,12] p = 0,018). No grupo com diabetes, a aldosterona correlacionou-se com DBFnu (r = 0,72 [0,16 - 0,93] p = 0,019) e DAFnu (r = -0,72 [-0,93 - -0,16] p = 0,019). Apesar da importância da leptina na atividade simpática aumentada na hipertensão, não houve correlação com VFC. CONCLUSÃO: A aldosterona parece estimular a atividade simpática em HR com ou sem DT2. Essa informação combinada com a eficácia clínica dos bloqueadores de receptor mineralocorticoide em HR pode reforçar a aldosterona como alvo terapêutico relevantes em HR. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0)

Einfluss des mentalen Lernens auf die Technikoptimierung in der Kampfsportart Judo unter den Bedingungen der Grundausbildung : dargestellt an der Technik "O-Goshi"

Sport "Sporttechnik, Messplatztraining, Bewegungswissenschaft, Bewegungsrepräsentation, Trainingsmethoden, motorisches Training, Judo". Pädagogik "Lernsystem, Lernprozess, Bildung". Psychologie "mentales Training, ideomotorisches Training". Technologie "Computerprogramme".

Design and development of high gain wideband microstrip antenna and DGS filters using numerical experimentation approach

Microstrip antenna, Wideband antennas, high gain antennas, Microstrip filters, DGS filters , low-pass filter, band-pass filter

Enhancing the performance of spread spectrum techniques in different applications

Spread spectrum, Automotive Radar, Indoor Positioning Systems, Ultrasonic and Microwave Imaging, super resolution technique and wavelet transform

Mathematical model to analyze the heat transfer in tunnel kilns for burning of ceramics

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2013

Motor and cognitive development of selected Egyptian and German primary school aged children : a cross-cultural study

Magdeburg, Univ., Fak. für Humanwiss., Diss., 2013