Search for top-quark partners with charge 5/3 in the same-sign dilepton final state

ArXiv 1312.2391 (2013)

Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at sqrt(s[NN]) = 2.76 TeV

ArXiv 1312.1845 (2013)

Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states

ArXiv 1312.1129 (2013)

Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at √s = 7 TeV

European Physical Journal C 73:12 (2013) 1-26

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, N Hörmann, J Hrubec, M Jeitler, W Kiesenhofer, V Knünz, M Krammer, I Krätschmer, D Liko, I Mikulec, D Rabady, B Rahbaran, C Rohringer, H Rohringer, R Schöfbeck, J Strauss, A Taurok, W Treberer-Treberspurg, W Waltenberger, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, S Alderweireldt, M Bansal, S Bansal, T Cornelis, EA De Wolf, X Janssen, A Knutsson, S Luyckx, L Mucibello, S Ochesanu, B Roland, R Rougny, Z Staykova, H Van Haevermaet, P Van Mechelen, N Van Remortel, A Van Spilbeeck, F Blekman, S Blyweert, J D'Hondt, A Kalogeropoulos, J Keaveney, S Lowette, M Maes, A Olbrechts, S Tavernier, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, C Caillol, B Clerbaux, G De Lentdecker, L Favart, APR Gay, T Hreus, A Léonard, PE Marage, A Mohammadi, L Perniè, T Reis, T Seva, L Thomas, C Vander Velde, P Vanlaer, J Wang, V Adler, K Beernaert, L Benucci, A Cimmino, S Costantini, S Dildick, G Garcia, B Klein, J Lellouch, A Marinov, J Mccartin, AA Ocampo Rios, D Ryckbosch, M Sigamani, N Strobbe, F Thyssen, M Tytgat, S Walsh, E Yazgan, N Zaganidis

Abstract:

Characteristics of multi-particle production in proton-proton collisions at √s = 7 TeV are studied as a function of the charged-particle multiplicity, N ch. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity {pipe}η{pipe}<2.4 and transverse momentum p T>0.25 GeV/c. Jets are reconstructed from charged-particles only and required to have p T>5 GeV/c. The distributions of jet p T, average p T of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N ch and compared to the predictions of the pythia and herwig event generators. Predictions without multi-parton interactions fail completely to describe the N ch-dependence observed in the data. For increasing N ch, pythia systematically predicts higher jet rates and harder p T spectra than seen in the data, whereas herwig shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients. © 2013 CERN for the benefit of the CMS collaboration.

Search for top-squark pair production in the single-lepton final state in pp collisions at √s = 8 TeV

European Physical Journal C 73:12 (2013) 1-46

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, N Hörmann, J Hrubec, M Jeitler, W Kiesenhofer, V Knünz, M Krammer, I Krätschmer, D Liko, I Mikulec, D Rabady, B Rahbaran, C Rohringer, H Rohringer, R Schöfbeck, J Strauss, A Taurok, W Treberer-Treberspurg, W Waltenberger, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, S Alderweireldt, M Bansal, S Bansal, T Cornelis, EA De Wolf, X Janssen, A Knutsson, S Luyckx, L Mucibello, S Ochesanu, B Roland, R Rougny, Z Staykova, H Van Haevermaet, P Van Mechelen, N Van Remortel, A Van Spilbeeck, F Blekman, S Blyweert, J D'Hondt, A Kalogeropoulos, J Keaveney, S Lowette, M Maes, A Olbrechts, S Tavernier, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, C Caillol, B Clerbaux, G De Lentdecker, L Favart, APR Gay, T Hreus, A Léonard, PE Marage, A Mohammadi, L Perniè, T Reis, T Seva, L Thomas, C Vander Velde, P Vanlaer, J Wang, V Adler, K Beernaert, L Benucci, A Cimmino, S Costantini, S Dildick, G Garcia, B Klein, J Lellouch, A Marinov, J Mccartin, AA Ocampo Rios, D Ryckbosch, M Sigamani, N Strobbe, F Thyssen, M Tytgat, S Walsh, E Yazgan, N Zaganidis

Abstract:

This paper presents a search for the pair production of top squarks in events with a single isolated electron or muon, jets, large missing transverse momentum, and large transverse mass. The data sample corresponds to an integrated luminosity of 19.5 fb-1 of pp collisions collected in 2012 by the CMS experiment at the LHC at a center-of-mass energy of √s = 8 TeV. No significant excess in data is observed above the expectation from standard model processes. The results are interpreted in the context of supersymmetric models with pair production of top squarks that decay either to a top quark and a neutralino or to a bottom quark and a chargino. For small mass values of the lightest supersymmetric particle, top-squark mass values up to around 650 GeV are excluded. © 2013 CERN for the benefit of the CMS collaboration.