Accelerator Neutrinos

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Search for pair production of a new b′ quark that decays into a Z boson and a bottom quark with the ATLAS detector

Physical Review Letters 109:7 (2012)

Authors:

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, E Acerbi, BS Acharya, L Adamczyk, 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, J Albert, 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, BMM Allbrooke, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, B Alvarez Gonzalez, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, A Anisenkov, 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, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster

Abstract:

A search is reported for the pair production of a new quark b′ with at least one b′ decaying to a Z boson and a bottom quark. The data, corresponding to 2.0fb-1 of integrated luminosity, were collected from pp collisions at √s=7TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b′ candidates is tested for an enhancement. No evidence for a b′ signal is detected in the observed mass distribution, resulting in the exclusion at a 95% confidence level of b′ quarks with masses m b′<400GeV that decay entirely via b′→Z+b. In the case of a vectorlike singlet b′ mixing solely with the third standard model generation, masses mb′<358GeV are excluded. © 2012 CERN.

Measurements of atmospheric neutrinos and antineutrinos in the MINOS Far Detector

(2012)

Authors:

MINOS Collaboration, P Adamson, C Backhouse, G Barr, M Bishai, AST Blake, GJ Bock, DJ Boehnlein, D Bogert, SV Cao, JD Chapman, S Childress, JAB Coelho, L Corwin, D Cronin-Hennessy, IZ Danko, JK de Jong, NE Devenish, MV Diwan, CO Escobar, JJ Evans, E Falk, GJ Feldman, MV Frohne, HR Gallagher, RA Gomes, MC Goodman, P Gouffon, N Graf, R Gran, K Grzelak, A Habig, J Hartnell, R Hatcher, A Himmel, A Holin, J Hylen, GM Irwin, Z Isvan, DE Jaffe, C James, D Jensen, T Kafka, SMS Kasahara, G Koizumi, S Kopp, M Kordosky, A Kreymer, K Lang, J Ling, PJ Litchfield, L Loiacono, P Lucas, WA Mann, ML Marshak, M Mathis, N Mayer, MM Medeiros, R Mehdiyev, JR Meier, MD Messier, WH Miller, SR Mishra, J Mitchell, CD Moore, L Mualem, S Mufson, J Musser, D Naples, JK Nelson, HB Newman, RJ Nichol, JA Nowak, WP Oliver, M Orchanian, RB Pahlka, J Paley, RB Patterson, G Pawloski, S Phan-Budd, RK Plunkett, X Qiu, A Radovic, J Ratchford, B Rebel, C Rosenfeld, HA Rubin, MC Sanchez, J Schneps, A Schreckenberger, P Schreiner, R Sharma, A Sousa, B Speakman, M Strait, N Tagg, RL Talaga, J Thomas, MA Thomson, R Toner, D Torretta, G Tzanakos, J Urheim, P Vahle, B Viren, JJ Walding, A Weber, RC Webb, C White, L Whitehead, SG Wojcicki, K Zhang, R Zwaska

Search for events with large missing transverse momentum, jets, and at least two tau leptons in 7 TeV proton-proton collision data with the ATLAS detector

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 714:2-5 (2012) 180-196

Authors:

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, E Acerbi, E Acerbi, BS Acharya, BS Acharya, L Adamczyk, 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, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, J Albert, 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, BMM Allbrooke, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, A Aloisio, R Alon, A Alonso, B Alvarez Gonzalez, MG Alviggi, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, A Anisenkov, 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

Abstract:

A search for events with large missing transverse momentum, jets, and at least two tau leptons has been performed using 2 fb-1 of proton-proton collision data at s=7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95% CL upper limit on the visible cross section for new phenomena is set, where the visible cross section is defined by the product of cross section, branching fraction, detector acceptance and event selection efficiency. A 95% CL lower limit of 32 TeV is set on the gauge-mediated supersymmetry breaking (GMSB) scale Λ independent of tanβ. These limits provide the most stringent tests to date in a large part of the considered parameter space. © 2012.

Search for supersymmetry with jets, missing transverse momentum and at least one hadronically decaying Ï„ lepton in proton-proton collisions at s=7TeV with the ATLAS detector

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 714:2-5 (2012) 197-214

Authors:

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, E Acerbi, E Acerbi, BS Acharya, BS Acharya, L Adamczyk, 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, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, J Albert, 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, BMM Allbrooke, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, A Aloisio, R Alon, A Alonso, B Alvarez Gonzalez, MG Alviggi, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, A Anisenkov, 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

Abstract:

A search for production of supersymmetric particles in final states containing jets, missing transverse momentum, and at least one hadronically decaying τ lepton is presented. The data were recorded by the ATLAS experiment in s=7TeV proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 2.05fb-1 of data. The results are interpreted in the context of gauge mediated supersymmetry breaking models with Mmess=250TeV, N5=3, μ>0, and Cgrav=1. The production of supersymmetric particles is excluded at 95% C.L. up to a supersymmetry breaking scale Λ=30TeV, independent of tanβ, and up to Λ=43TeV for large tanβ. © 2012.

Search for charged Higgs bosons decaying via H± → τν in tt̄ events using pp collision data at √s = 7 TeV with the ATLAS detector

Journal of High Energy Physics 2012:6 (2012)

Authors:

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, O Abdinov, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, E Acerbi, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, 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, J Albert, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, BMM Allbrooke, PP Allport, SE Allwoo-Spiers, J Almond, A Aloisio, R Alon, A Alonso, B Alvarez Gonzalez, MG Alviggi, K Amako, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, S Aoun, LB Aperio, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster, O Arnaez, V Arnal, C Arnault, A Artamonov, G Artoni

Abstract:

The results of a search for charged Higgs bosons are presented. The analysis is based on 4.6 fb?1 of proton-proton collision data at √s = 7TeV collected by the ATLAS experiment at the Large Hadron Collider, using top quark pair events with a τ lepton in the final state. The data are consistent with the expected background from Standard Model processes. Assuming that the branching ratio of the charged Higgs boson to a τ lepton and a neutrino is 100%, this leads to upper limits on the branching ratio of top quark decays to a b quark and a charged Higgs boson between 5% and 1% for charged Higgs boson masses ranging from 90GeV to 160GeV, respectively. In the context of the mhmaxscenario of the MSSM, tan β above 12-26, as well as between 1 and 2-6, can be excluded for charged Higgs boson masses between 90GeV and 150GeV. Copyright CERN.