1 5 Permanents (3 EC, 2 CNRS) Tristan Beau [Masse – SLHC] Frédéric Derue [Section efficace – e/gamma, calcul] Didier Lacour [Masse – calorimètre] Mélissa Ridel [Masse, section efficace – calorimètre, e/gamma] Sophie Trincaz-Duvoid [Masse, section efficace – calorimètre, e/gamma] 1 Postdoctorant Eric Cogneras [Masse – premières données, calcul] 4 Doctorants Stefania Bordoni [Section efficace – calorimètre, e/gamma] Timothée Theveneaux-Pelzer [Section efficace – calorimètre, e/gamma] A partir de septembre 2011 : Aurélien Demilly [Masse] Guillaume Lefebvre [Section efficace] Visiteurs Robert Cahn (MC2, P2I) Anna Kaczmarska (accords de coopération IN2P3 COPIN, professeur invitée P7) Ivo Van Vulpen (EGID) 2-3 stagiaires / an Collaborations NIKHEF (MR, ST,SB), Pologne (FD) - Demande ANR jeune chercheur (MR) La physique du quark top au LPNHE avec le détecteur Atlas Didier Lacour, mai 2011

2 Detector activities and computing Grid Lar Calorimeter high voltage monitoring Lar Calorimeter electronic calibration EM calorimeter operation Physics groups Top WG Standard Model WG Top sub-groups Top reconstruction group Top cross-section group Top mass group Performance groups e/gamma WG Flavour Tagging WG Jet/EtMiss WG Implications dans la collaboration Atlas Analysis performed in the group: Reconstruction and identification of electrons Electron performance using the J/psi->e+e- decays Measurement of the inclusive electron cross-section from the decays of heavy flavour hadrons Top mass measurement in the dilepton channel Top cross section measurement in the multi-lepton channel Top cross section measurement in the full hadronic channel

3 Conférences – workshops P. Cavalleri : Physics at LHC 2008, Split, Croatia, 29 Sep - 04 Oct 2008 « Top mass measurement with ATLAS » Conf Note support for « Electron and Photon Performance and Electron pT Spectrum Measurement with ATLAS in pp Collisions at sqrt(s)=7 TeV » ICHEP 2010, T. Theveneaux-Pelzer « Electron performance with J/psi with the ATLAS detector (student's talk), Epiphanyconference on the first year of the LHC », Cracovie, Pologne, janvier 2011 S. Bordoni « Measurements of the inclusive electron cross-section in proton-proton collisions at sqrt s = 7 TeV with the ATLAS detector » poster submited EPS 2011, Grenoble T. Theveneaux-Pelzer « Electron efficiency measurement at low energieswith J/psi » poster submited EPS 2011, Grenoble Thèses soutenue et en cours Etude de faisabilité de la mesure de masse du quark top dans le canal électron-muon avec le détecteur Atlas auprès du LHC (Pietro Cavalleri, soutenue en septembre 2009) Mesure de la section efficace de production des quarks beaux et charmes a partir de leur desintegration semileptonique en electrons avec l'experience ATLAS dans les collisions protons-protons a sqrt(s) = 7 TeV au LHC. (Stefania Bordoni, soutenance en 2011) Mesure de la section efficace de production de paires de quarks top dans les canaux multi leptons (Timothée Theveneaux-Pelzer, soutenance en 2012) Possibles habilitations à diriger les recherches Généralisation et extension de la méthode des éléments de matrice – prospective pour l’échelle en énergie des jets – JES (Mélissa Ridel, 2011) Mesure de la section efficace de production de paires ttbar (Sophie Trincaz-Duvoid, 2013) Mesure de la masse du quark top (Tristan Beau, 2014) Postdocs Mesure de la masse : éléments de matrice, e-mu, 7 TeV (Eric Cogneras) Futures thèses (à partir de septembre 2011, soutenances en 2014) Mesure de la section efficace dans la canal tout hadronique (Guillaume Lebebvre) Mesure de la masse dans le canal di-leptonique (Aurélien Demilly) Conférences, thèses, postdocs et habilitations

4 Investigating the possibility of the top quark mass measurement with the matrix element method in the dilepton final state with the ATLAS detector at the LHC / Cavalleri, P; Derue, F; Lacour, D; Nikolic-Audit, I; Ridel, M; Trincaz-Duvoid, S; ATL- COM-PHYS Geneva : CERN, p Top Quark Mass Measurements / P. Cavalleri, E. Cogneras, K. Edmonds, A.-I. Etienvre, R. Klingenberg, D. Lacour, M. Lefebvre, A. Marzin, J.-P. Meyer, D. Pallin, I. Reisinger, M. Ridel, J. Schwindling, R. Seuster, S. Trincaz-Duvoid, J. Walbersloh ; ATL-COM-PHYS Geneva : CERN, 2009 – 26 p Top mass measurement in the electron-muon channel using the matrix element method with the first expected data of the ATLAS detector at 14 TeV: prospective study / Cavalleri, P; Lacour, D ; Ridel, M ; Trincaz-Duvoid, S / ATL-COM-PHYS Geneva : CERN, p Study on reconstructed object definition and selection for top physics /Abbott, B; Allwood-Spiers, S; Astalos, R; de Bell, M; Benekos, N; BoisVert, V; Bordoni, S; Brooijmans, G; De Bruyn, K; Cerrito, L et al. Ridel, M ; Trincaz-Duvoid, S / ATL-COM- PHYS Geneva : CERN, p. Monte Carlo study of isolated leptons in multi-jet events / Bordoni, S; Doxiadis, A; Ridel, M; Trincaz-Duvoid, S; Van Vulpen, I / ATL-PHYS-INT ; ATL-COM-PHYS Geneva : CERN, p. Comparison between FullSim and ATLFAST II detector simulation performances in ttbar dilepton events. / Bordoni, S ; Ridel, M ; Trincaz-Duvoid, S / ATL-PHYS-INT ; ATL-COM-PHYS Geneva : CERN, p. Soft electron b-tagging with CSC data / Derue, F; Kaczmarska, A / ATL-COM-PHYS Geneva : CERN, 2008 Electron efficiency measurements using ATLAS 2010 data at sqrt(s) = 7 TeV, ATLAS Coll., ATL-COM-PHYS Electron performance of the ATLAS detector using the J/psi->e+e- decays, Aharrouche M., et al, ATL-PHYS-INT Lepton trigger and identification for the Winter 2011 top quark analyses, N. Benekos et al., ATL-COM-PHYS Background studies for top-pair production in lepton plus jets final states in sqrt(s)=7 TeV ATLAS data, B. Abi et al., ATL- COM-CONF Notes COM Atlas (rédacteurs - co-auteurs)

5 Expected Performance of the ATLAS Experiment, Detector, Trigger and Physics ("CSC book") CERN-OPEN (notes, "Jpsi->ee","softe b-tag") / Derue, F The ATLAS Experiment at the CERN Large Hadron Collider 2008 JINST 3 S08003 (chapt electron, b-tag) / Derue, F Expected electron performance in the ATLAS experiment, (ATLAS Coll.), ATLAS-PHYS-PUB Reconstruction and identification of electrons, ATLAS Coll., ATL-PHYS-PUB Reconstruction of low-mass electron pairs, ATLAS Coll., ATL-PHYS-PUB Monte Carlo study of isolated leptons in multi-jet events / Bordoni, S; Doxiadis, ; Ridel, M; Trincaz-Duvoid, S; Van Vulpen, I Comparison between FullSim and ATLFAST II detector simulation performances in ttbar dilepton events. / Bordoni, S ; Ridel, M ; Trincaz-Duvoid, S M. Ridel Editor : Measurements of the inclusive electron and muon cross-sections in proton-proton collisions at sqrt s= 7 TeV with the ATLAS detector / Antonelli, M; Backes, M; Baroncelli, T Bell, P; Bordoni, S; Ceradini, F; Di Micco, B; Farilla, A; Fedorko, W; Flowerdew, M e al. Measurement of the inclusive electron cross-section from the decays of heavy flavour hadrons in pp collisions at $sqrt{s}=7TeV / Backes, M; Bell,; Bordoni, C; Fedorko, W; Flowerdew, M; Froidevaux, D; Gadomski, S; Mora Herrera, C; Pasztor, G; Ridel, M et al. Study of the impact of the typical variations of the electronic calibration constants on the cell reconstructed energies of the LAr barrel electromagnetic calorimeter / Bordoni, S; Delmastro, M; Ridel, M; Trincaz-Duvoid, S Mis-identified lepton backgrounds to top quark pair production : Supporting note 5 / Abi, B; Adelman, J; Almond, J; Arguin, J F; Besana, I; Bordoni, S; Bosman, M; Brau, J; Cortes-Gonzalez, A; Doxiadis, A et al. Study on reconstructed object definition and selection for top physics / Abbott, B; Allwood-Spiers,S; Astalos, R; de Bell, M; Benekos, N; BoisVert, V; Bordoni, S; Brooijmans, G; De Bruyn, K; Cerrito, L et al. Electron performance with J/psi with the ATLAS detector / ATL-PHYS-PROC , T. Theveneaux-Pelzer Notes Atlas - Articles (rédacteurs - co-auteurs)