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Observation of a new 蠂b state in radiative transitions to Y(1S) and Y(2S) at ATLAS

Physical Review Letters 108:15 (2012)

Authors:

G Aad, B Abbott, J Abdallah, 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 Kesson, 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 Amor贸s, 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, O Arnaez

Abstract:

The 蠂b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at 鈭歴=7TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4fb-1, these states are reconstructed through their radiative decays to 违(1S,2S) with 违鈫捨+渭-. In addition to the mass peaks corresponding to the decay modes 蠂 b(1P,2P)鈫捨(1S)纬, a new structure centered at a mass of 10.530卤0.005(stat)卤0.009(syst)GeV is also observed, in both the 违(1S)纬 and 违(2S)纬 decay modes. This structure is interpreted as the 蠂b(3P) system. 漏 2012 CERN.

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

ArXiv 1204.1643 (2012)

Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at nucleon-nucleon center-of-mass energy = 2.76 TeV

ArXiv 1204.1409 (2012)

Measurement of the underlying event in the Drell-Yan process in proton-proton collisions at sqrt(s) = 7 TeV

ArXiv 1204.1411 (2012)

An additional study of multi-muon events produced in pp- collisions at s=1.96 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 710:2 (2012) 278-283

Authors:

T Aaltonen, B 脕lvarez Gonz谩lez, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, B Auerbach, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, C Calancha, M Campanelli, M Campbell, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, A Cerri, L Cerrito, YC Chen, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, C Cuenca Almenar, J Cuevas, D Dagenhart, N d'Ascenzo, M Datta, P de Barbaro, S De Cecco, M Dell'Orso, L Demortier, J Deng, M Deninno, F Devoto, M d'Errico

Abstract:

We present one additional study of multi-muon events produced at the Fermilab Tevatron collider and recorded by the CDF II detector. We use a data set acquired with a dedicated dimuon trigger and corresponding to an integrated luminosity of 3.9 fb -1. We investigate the distribution of the azimuthal angle between the two trigger muons in events containing at least four additional muon candidates to test the compatibility of these events with originating from known QCD processes. We find that this distribution is markedly different from what is expected from such QCD processes and this observation strongly disfavors the possibility that multi-muon events result from an underestimate of the rate of misidentified muons in ordinary QCD events. 漏 2012 Elsevier B.V.