Observation of Spin Correlation in t(t)over-bar Events from pp Collisions at root s=7 TeV Using the ATLAS Detector
Makaleler > Tam Makale · 2012
Yazarlar: G. Aad, B. Abbott, J. Abdallah, S. Abdel Khalek, A. A. Abdelalim, A. Abdesselam, O. Abdinov, B. Abi, M. Abolins, O. S. AbouZeid, H. Abramowicz, H. Abreu, E. Acerbi, B. S. Acharya, L. Adamczyk, D. L. Adams, T. N. Addy, J. Adelman, M. Aderholz, S. Adomeit, P. Adragna, T. Adye, S. Aefsky, J. A. Aguilar-Saavedra, M. Aharrouche, S. P. Ahlen, F. Ahles, A. Ahmad, M. Ahsan, G. Aielli, T. Akdogan, T. P. A. Akesson, G. Akimoto, A. V. Akimov, A. Akiyama, M. S. Alam, M. A. Alam, J. Albert, S. Albrand, M. Aleksa, I. N. Aleksandrov, F. Alessandria, C. Alexa, G. Alexander, G. Alexandre, T. Alexopoulos, M. Alhroob, M. Aliev, G. Alimonti, J. Alison, M. Aliyev, B. M. M. Allbrooke, P. P. Allport, S. E. Allwood-Spiers, J. Almond, A. Aloisio, R. Alon, A. Alonso, B. Alvarez Gonzalez, M. G. Alviggi, K. Amako, P. Amaral, C. Amelung, V. V. Ammosov, A. Amorim, G. Amoros, N. Amram, C. Anastopoulos, L. S. Ancu, N. Andari, T. Andeen, C. F. Anders, G. Anders, K. J. Anderson, A. Andreazza, V. Andrei, M-L. Andrieux, X. S. 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, A. T. H. Arce, S. Arfaoui, J-F. Arguin, E. Arik, M. Arik, A. J. Armbruster, K. Augsten, M. Aurousseau, A. Bangert, D. Benchekroun, S. Bentvelsen, N. Boelaert, A. Bogouch, W. K. Brooks, T. Buanes, L. P. Caloba, L. Chikovani, M. L. Chu, Rena ÇİFTÇİ, V. Cindro, B. Epp, H. Hakobyan, M. Losada
PHYSICAL REVIEW LETTERS, SCI Expanded İndekslerine Giren Dergi, Uluslararası, 2012, cilt 108
DOI: 10.1103/physrevlett.108.212001
Özet
A measurement of spin correlation in t (t) over bar production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb(-1). Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to A(helicity) = 0.40(-0.08)(+0.09), in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations.