Search for pair production of first or second generation leptoquarks in proton-proton collisions at 鈭歴=7TeV using the ATLAS detector at the LHC

Physical Review D - Particles, Fields, Gravitation and Cosmology 83:11 (2011)

Authors:

G Aad, B Abbott, J Abdallah, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu, E Acerbi, BS Acharya, DL Adams, TN Addy, J Adelman, M Aderholz, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA 脕kesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, M Aliyev, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amor贸s, N Amram, C Anastopoulos, T Andeen, CF Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, N Anjos, A Annovi, A Antonaki, M Antonelli, S Antonelli, A Antonov, J Antos, F Anulli, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, JP Archambault, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster, O Arnaez, C Arnault, A Artamonov, G Artoni, D Arutinov, S Asai, R Asfandiyarov, S Ask

Abstract:

This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35pb-1 of proton-proton collision data recorded by the ATLAS detector at 鈭歴=7TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95 CL for masses MLQ<376 (319) GeV and MLQ<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5). 漏 2011 American Physical Society.

Upsilon production cross section in pp collisions at 鈭歴=7TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 83:11 (2011)

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Er枚, C Fabjan, M Friedl, R Fr眉hwirth, VM Ghete, J Hammer, S H盲nsel, C Hartl, M Hoch, N H枚rmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Sch枚fbeck, J Strauss, A Taurok, F Teischinger, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, L Ceard, K Cerny, EA De Wolf, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, F Blekman, S Blyweert, J D'Hondt, O Devroede, R Gonzalez Suarez, A Kalogeropoulos, J Maes, M Maes, S Tavernier, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Hammad, T Hreus, PE Marage, L Thomas, C Vander Velde, P Vanlaer, J Wickens, S Costantini, M Grunewald, B Klein, A Marinov, J McCartin, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, J De Favereau De Jeneret, C Delaere, P Demin, D Favart, A Giammanco, G Gr茅goire, J Hollar, V Lemaitre

Abstract:

The 违(1S), 违(2S), and 违(3S) production cross sections in proton-proton collisions at 鈭歴=7TeV are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1卤0.3pb -1. Integrated over the rapidity range |y|<2, we find the product of the 违(1S) production cross section and branching fraction to dimuons to be 蟽(pp鈫捨�(1S)X) 鈥(违(1S)鈫捨� +渭 -)=7.37卤0.13-0. 42+0.61卤0.81nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized 违(1S) production. With the assumption of fully transverse or fully longitudinal production polarization, the measured cross section changes by about 20%. We also report the measurement of the 违(1S), 违(2S), and 违(3S) differential cross sections as a function of transverse momentum and rapidity. 漏 2011 American Physical Society.

Measurement of the differential dijet production cross section in proton-proton collisions at 鈭歴=7 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 700:3-4 (2011) 187-206

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Er枚, C Fabjan, M Friedl, R Fr眉hwirth, VM Ghete, J Hammer, S H盲nsel, M Hoch, N H枚rmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Sch枚fbeck, J Strauss, F Teischinger, P Wagner, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, EA De Wolf, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, F Blekman, S Blyweert, J D'Hondt, O Devroede, R Gonzalez Suarez, A Kalogeropoulos, J Maes, M Maes, W Van Doninck, P Van Mulders, GP Van Onsem, I Villella, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Hammad, T Hreus, PE Marage, L Thomas, C Vander Velde, P Vanlaer, V Adler, A Cimmino, S Costantini, M Grunewald, B Klein, J Lellouch, A Marinov, J Mccartin, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, L Ceard, E Cortina Gil, J De Favereau De Jeneret, C Delaere, D Favart, A Giammanco, G Gr茅goire, J Hollar, V Lemaitre, J Liao, O Militaru

Abstract:

A measurement of the double-differential inclusive dijet production cross section in proton-proton collisions at 鈭歴=7 TeV is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 pb-1, recorded with the CMS detector at the LHC. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to |y|=2.5. It is found to be in good agreement with next-to-leading-order QCD predictions. 漏 2011 CERN.

Search for Light Resonances Decaying into Pairs of Muons as a Signal of New Physics

ArXiv 1106.2375 (2011)

Search for high mass dilepton resonances in pp collisions at 鈭歴=7 TeV with the ATLAS experiment

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 700:3-4 (2011) 163-180

Authors:

G Aad, B Abbott, J Abdallah, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu, E Acerbi, BS Acharya, DL Adams, TN Addy, J Adelman, M Aderholz, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA 脜kesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, M Aliyev, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amor贸s, N Amram, C Anastopoulos, T Andeen, CF Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, N Anjos, A Annovi, A Antonaki, M Antonelli, S Antonelli, A Antonov, J Antos, F Anulli, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, JP Archambault, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster, O Arnaez, C Arnault, A Artamonov, G Artoni, D Arutinov, S Asai, R Asfandiyarov, S Ask

Abstract:

This Letter presents a search for high mass e+e- or 渭+渭- resonances in pp collisions at 鈭歴=7 TeV at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of ~40 pb-1. No statistically significant excess above the Standard Model expectation is observed in the search region of dilepton invariant mass above 110 GeV. Upper limits at the 95% confidence level are set on the cross section times branching ratio of Z' resonances decaying to dielectrons and dimuons as a function of the resonance mass. A lower mass limit of 1.048 TeV on the Sequential Standard Model Z' boson is derived, as well as mass limits on Z* and E6-motivated Z' models. 漏 2011 CERN.