How experience influences infants’ recognition of male and female faces

Young infants with female primary caregivers are able to differentiate familiar female faces from novel female faces but not male faces. Experience processing faces may be important for being able to discriminate among similar-looking faces. Subsequently, increasing infants’ experience with less familiar faces should improve their ability to differentiate those types of faces. This study examined if infants’ experience with faces affected their recognition of new faces. Prior to testing, 2-3 month old infants were assigned to one of three conditions: a male video, a female video, and no video condition. Infants were familiarized to both male and female faces during test. For the male faces, infants who saw the male video showed a familiarity preference, infants who saw the female video showed a novelty preference, and infants who saw no video showed no preference. For female faces, infants showed no preference when assigned to the male video and no video condition, while infants assigned to the female video (n = 5) showed a familiarity preference. A follow up infant-controlled habituation study tested if infants processed faces featurally or holistically. During testing, infants saw one familiar face, one composite face, and one novel face. None of the infants in the male video, female video, or no video conditions were able to distinguish the familiar face from the composite face. Only infants in the female video condition showed an increase in looking time from the familiar face to the novel face

Measurement of the top quark pair production cross section in pp collisions at root s=7 TeV in dilepton final states with ATLAS

A measurement of the production cross section of top quark pairs (t (t) over bar) in proton-proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the Large Hadron Collider is reported. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. Using a data sample corresponding to an integrated luminosity of 35 pb(-1), a t (t) over bar production cross section sigma(t (t) over bar) = 177 +/- 20(stat.) +/- 14(syst.) +/- 7(lum.) pb is measured for an assumed top quark mass of m(t) = 172.5 GeV. A second measurement requiring at least one jet identified as coming from a b quark yields a comparable result, demonstrating that the dilepton final states are consistent with being accompanied by b-quark jets. These measurements are in good agreement with Standard Model predictions. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved

Search for diphoton events with large missing transverse momentum in 7 TeV proton-proton collision data with the ATLAS detector

A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at is root s = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb(-1). No excess of events was observed above the Standard Model prediction and model-dependent 95% confidence level exclusion limits are set. In the context of a generalised model of gauge-mediated supersymmetry breaking with a bino-like lightest neutralino of mass above 50 GeV, gluinos (squarks) below 1.07 TeV (0.87 TeV) are excluded, while a breaking scale Lambda below 196 TeV is excluded for a minimal model of gauge-mediated supersymmetry breaking. For a specific model with one universal extra dimension, compactification scales 1/R < 1.40 TeV are excluded. These limits provide the most stringent tests of these models to date. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved

Charged Particle Multiplicities in pp Interactions Measured with the ATLAS Detector at the LHC

Measurements are presented from proton–proton collisions at centre-of-mass energies of \sqrt{s} = 0.9 , 2.36 and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections. The results are compared to each other and to various Monte Carlo (MC) models, including a new AMBT1 pythia6 tune. In all the kinematic regions considered, the particle multiplicities are higher than predicted by the MC models. The central charged-particle multiplicity per event and unit of pseudorapidity, for tracks with pT>100 MeV, is measured to be 3.483±0.009 (stat)±0.106 (syst) at \sqrt{s} = 0.9\,{\rm TeV} and 5.630±0.003 (stat)±0.169 (syst) at \sqrt{s} = 7\,{\rm TeV}

Search for Magnetic Monopoles in root s=7 TeV pp Collisions with the ATLAS Detector

This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0 fb\u20131of pp collisions recorded at a center-of-mass energy of 1as = 7 TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/\u3f5 fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeVand 1500 GeV, where \u3f5 is the monopole reconstruction efficiency. The efficiency \u3f5 is high and uniform in the fiducial region given by pseudorapidity 23\u3b7 23 < 1.37 and transverse kinetic energy 600\u2013700 < Ekinsin\u3b8 < 1400 GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1/2 Dirac magnetic monopoles, the efficiency is in the range 1%\u201310%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region

Search for the Standard Model Higgs boson produced in association with a vector boson and decaying to a b-quark pair with the ATLAS detector

This Letter presents the results of a direct search with the ATLAS detector at the LHC for a Standard Model Higgs boson of mass 110 llbb, WH->lvbb, and ZH->vvbb, where l corresponds to an electron or a muon. No evidence for Higgs boson production is observed in a dataset of 7 TeV pp collisions corresponding to 4.7/fb of integrated luminosity collected by ATLAS in 2011. Exclusion limits on Higgs boson production, at the 95% confidence level, of 2.5 to 5.5 times the Standard Model cross section are obtained in the mass range 110 - 130 GeV. The expected exclusion limits range between 2.5 and 4.9 for the same mass interval