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Inclusive and differential measurements of the tt- charge asymmetry in proton-proton collisions at s=7 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 717:1-3 (2012) 129-150

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, E Aguilo, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, N Hörmann, J Hrubec, M Jeitler, W Kiesenhofer, V Knünz, M Krammer, D Liko, I Mikulec, M Pernicka, B Rahbaran, C Rohringer, H Rohringer, R Schöfbeck, J Strauss, A Taurok, P Wagner, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, S Bansal, T Cornelis, EA De Wolf, X Janssen, S Luyckx, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, Z Staykova, H Van Haevermaet, P Van Mechelen, N Van Remortel, A Van Spilbeeck, F Blekman, S Blyweert, J D'Hondt, R Gonzalez Suarez, A Kalogeropoulos, M Maes, A Olbrechts, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, B Clerbaux, G De Lentdecker, V Dero, APR Gay, T Hreus, A Léonard, PE Marage, T Reis, L Thomas, C Vander Velde, P Vanlaer, J Wang, V Adler, K Beernaert, A Cimmino, S Costantini, G Garcia, M Grunewald, B Klein, J Lellouch, A Marinov, J McCartin, AA Ocampo Rios, D Ryckbosch, N Strobbe, F Thyssen, M Tytgat, P Verwilligen, S Walsh, E Yazgan, N Zaganidis, S Basegmez, G Bruno, R Castello, L Ceard, C Delaere, T du Pree

Abstract:

The tt- charge asymmetry is measured in events containing a charged lepton (electron or muon) and at least four jets, one of which is identified as originating from b-quark hadronization. The analyzed dataset corresponds to an integrated luminosity of 5.0 fb-1 collected with the CMS detector at the LHC. An inclusive and three differential measurements of the tt- charge asymmetry as a function of rapidity, transverse momentum, and invariant mass of the tt- system are presented. The measured inclusive tt- charge asymmetry is AC=0.004±0.010(stat.)±0.011(syst.). This result and the three differential measurements are consistent with zero asymmetry as well as with the predictions of the standard model. © 2012 CERN.
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Search for a Higgs boson in the diphoton final state using the full CDF data set from pp collisions at s=1.96TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 717:1-3 (2012) 173-181

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, T Bae, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, D Bisello, I Bizjak, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, C Bromberg, E Brucken, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, A Buzatu, A Calamba, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, WH Chung, YS Chung, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, J Cuevas, R Culbertson, D Dagenhart, N d'Ascenzo, M Datta, P de Barbaro, M Dell'Orso, L Demortier, M Deninno, F Devoto, M d'Errico

Abstract:

A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 10fb -1 of integrated luminosity collected by the CDF experiment from proton-antiproton collisions at s=1.96TeV. To increase the sensitivity of the search, we employ a multivariate discriminant technique for the first time in this channel at CDF. No evidence of signal is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of the Higgs boson mass. The limits are interpreted in the context of the standard model with an expected (observed) limit on the cross section times branching ratio of 9.9 (17.0) times the standard model prediction at the 95% credibility level for a Higgs boson mass of 125GeV/c 2. Moreover, a Higgs boson with suppressed couplings to fermions is excluded for masses below 114GeV/c 2 at the 95% credibility level. © 2012 Elsevier B.V.
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Search for heavy Majorana neutrinos in μ±μ±+jets and e±e±+jets events in pp collisions at s=7TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 717:1-3 (2012) 109-128

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, E Aguilo, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, N Hörmann, J Hrubec, M Jeitler, W Kiesenhofer, V Knünz, M Krammer, I Krätschmer, D Liko, I Mikulec, M Pernicka, B Rahbaran, C Rohringer, H Rohringer, R Schöfbeck, J Strauss, A Taurok, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, M Bansal, S Bansal, T Cornelis, EA De Wolf, X Janssen, S Luyckx, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, Z Staykova, H Van Haevermaet, P Van Mechelen, N Van Remortel, A Van Spilbeeck, F Blekman, S Blyweert, J D'Hondt, R Gonzalez Suarez, A Kalogeropoulos, M Maes, A Olbrechts, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, B Clerbaux, G De Lentdecker, V Dero, APR Gay, T Hreus, A Léonard, PE Marage, T Reis, L Thomas, G Vander Marcken, C Vander Velde, P Vanlaer, J Wang, V Adler, K Beernaert, A Cimmino, S Costantini, G Garcia, M Grunewald, B Klein, J Lellouch, A Marinov, J McCartin, AA Ocampo Rios, D Ryckbosch, N Strobbe, F Thyssen, M Tytgat, P Verwilligen, S Walsh, E Yazgan, N Zaganidis, S Basegmez, G Bruno, R Castello, L Ceard

Abstract:

A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98fb-1 of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events is observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing parameter, |VℓN|2, for ℓ=e, μ, as a function of heavy Majorana-neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for mN>90GeV. © 2012 CERN.
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Search for pair production of third-generation leptoquarks and top squarks in pp collisions at sqrt(s) = 7 TeV

ArXiv 1210.5629 (2012)
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Search for third-generation leptoquarks and scalar bottom quarks in pp collisions at sqrt(s) = 7 TeV

ArXiv 1210.5627 (2012)
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