Measurement of the lepton charge asymmetry in inclusive W production in pp collisions at √s = 7 TeV

Journal of High Energy Physics 2011:4 (2011)

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, J Hammer, S Hänsel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, 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 Grégoire, J Hollar, V Lemaitre, J Liao, O Militaru

Abstract:

A measurement of the lepton charge asymmetry in inclusive pp → WX production at √s = 7TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb -1. This high precision measurement of the lepton charge asymmetry, performed in both the W → eν and W → μν channels, provides new insights into parton distribution functions. Copyright CERN.

Measurement of the ratio of the 3-jet to 2-jet cross sections in pp collisions at s=7 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 702:5 (2011) 336-354

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, J Hammer, S Hänsel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, 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 Grégoire, J Hollar, V Lemaitre, J Liao, O Militaru

Abstract:

A measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum, HT, in the range 0.20.5 TeV. This measurement extends to an HT range that has not been explored before. © 2011 CERN Elsevier B.V.

Measurement of the Υ(1S) production cross-section in pp collisions at s=7 TeV in ATLAS

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:1-2 (2011) 9-27

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 Åkesson, 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 Amorós, N Amram, C Anastopoulos, N Andari, 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, 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:

A measurement of the cross-section for Υ(1S)→μ+μ- production in proton-proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the Υ(1S) transverse momentum in two bins of rapidity, |yΥ(1S)|<1.2 and 1.2<|yΥ(1S)|<2.4. The measurement requires that both muons have transverse momentum pTμ>4 GeV and pseudorapidity |ημ|<2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb-1, collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model. © 2011 CERN.

Measurements of inclusive W and Z cross sections in pp collisions at √s = 7 TeV The CMS collaboration

Journal of High Energy Physics 2011:1 (2011)

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hänsel, C Hartl, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, 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, E 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 Ds'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 Grégoire, J Hollar, V Lemaitre

Abstract:

Measurements of inclusive W and Z boson production cross sections in pp collisions at √s = 7 TeV are presented, based on 2.9 pb-1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp → WX) × B(W → l?) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ± 1.09 (lumi.) nb and σ(pp → ZX) × B(Z → l +l-) = 0.931 ± 0.026 (stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where l stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.

Search for a heavy bottom-like quark in pp collisions at √s=7 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 701:2 (2011) 204-223

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, J Hammer, S Hänsel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, 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, 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, L Ceard, E Cortina Gil, J De Favereau De Jeneret, C Delaere, D Favart, A Giammanco, G Grégoire, J Hollar, V Lemaitre, J Liao, O Militaru, S Ovyn, D Pagano

Abstract:

A search for pair-produced bottom-like quarks in pp collisions at √s=7 TeV is conducted with the CMS experiment at the LHC. The decay b'→tW is considered in this search. The b'b'→t∥W-t̄W+ process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb-1, no excess above the standard model background predictions is observed and a b' quark with a mass between 255 and 361 GeV/c2 is excluded at the 95% confidence level. © 2011 CERN.