Measurements of top quark spin observables in tt¯ events using dilepton final states in √s=8 TeV pp collisions with the ATLAS detector

Articolo

Data di Pubblicazione:

2017

Citazione:

Measurements of top quark spin observables in tt¯ events using dilepton final states in √s=8 TeV pp collisions with the ATLAS detector / M. Aaboud, G. Aad, B. Abbott, J. Abdallah, O. Abdinov, B. Abeloos, O. AbouZeid, N. Abraham, H. Abramowicz, H. Abreu, R. Abreu, Y. Abulaiti, B.S. Acharya, S. Adachi, L. Adamczyk, D. Adams, J. Adelman, S. Adomeit, T. Adye, T. Affolder, T. Agatonovic Jovin, J.A. Aguilar Saavedra, S. Ahlen, F. Ahmadov, G. Aielli, H. Akerstedt, T.P.A. Åkesson, A. Akimov, G.L. Alberghi, J. Albert, S. Albrand, M.J. Alconada Verzini, M. Aleksa, I. Aleksandrov, C. Alexa, G. Alexander, T. Alexopoulos, M. Alhroob, B. Ali, M. Aliev, G. Alimonti, J. Alison, S.P. Alkire, B. Allbrooke, B.W. Allen, P. Allport, A. Aloisio, A. Alonso, F. Alonso, C. Alpigiani, A.A. Alshehri, M. Alstaty, B. Alvarez Gonzalez, D. Άlvarez Piqueras, M. Alviggi, B.T. Amadio, Y. Amaral Coutinho, C. Amelung, D. Amidei, S.P. Amor Dos Santos, A. Amorim, S. Amoroso, G. Amundsen, C. Anastopoulos, L.S. Ancu, N. Andari, T. Andeen, C.F. Anders, J.K. Anders, K. Anderson, A. Andreazza, G.V. Andrei, S. Angelidakis, I. Angelozzi, A. Angerami, F. Anghinolfi, A. Anisenkov, N. Anjos, A. Annovi, C. Antel, M. Antonelli, A. Antonov, D.J. Antrim, F. Anulli, M. Aoki, L. Aperio Bella, G. Arabidze, Y. Arai, J.P. Araque, V. Araujo Ferraz, A. Arce, F.A. Arduh, J. Arguin, S. Argyropoulos, M. Arik, A.J. Armbruster, L.J. Armitage, O. Arnaez, H. Arnold, M. Arratia, O. Arslan, A. Artamonov, G. Artoni, S. Artz, S. Asai, N. Asbah, A. Ashkenazi, B. Åsman, L. Asquith, K. Assamagan, R. Astalos, M. Atkinson, N.B. Atlay, K. Augsten, G. Avolio, B. Axen, M.K. Ayoub, G. Azuelos, M. Baak, A. Baas, M.J. Baca, H. Bachacou, K. Bachas, M. Backes, M. Backhaus, P. Bagiacchi, P. Bagnaia, Y. Bai, J. Baines, M. Bajic, O.K. Baker, E. Baldin, P. Balek, T. Balestri, F. Balli, W.K. Balunas, E. Banas, S. Banerjee, A.A.E. Bannoura, L. Barak, E.L. Barberio, D. Barberis, M. Barbero, T. Barillari, M. Barisits, T. Barklow, N. Barlow, S.L. Barnes, B. Barnett, M. Barnett, Z. Barnovska Blenessy, A. Baroncelli, G. Barone, A. Barr, L. Barranco Navarro, F. Barreiro, J. Barreiro Guimarães da Costa, R. Bartoldus, A.E. Barton, P. Bartos, A. Basalaev, A. Bassalat, R. Bates, S.J. Batista, R. Batley, M. Battaglia, M. Bauce, F. Bauer, H.S. Bawa, J. Beacham, M.D. Beattie, T. Beau, P. Beauchemin, P. Bechtle, H. Beck, K. Becker, M. Becker, M. Beckingham, C. Becot, A. Beddall, A. Beddall, V. Bednyakov, M. Bedognetti, C. Bee, L. Beemster, T. Beermann, M. Begel, J.K. Behr, A.S. Bell, G. Bella, L. Bellagamba, A. Bellerive, M. Bellomo, K. Belotskiy, O. Beltramello, N. Belyaev, O. Benary, D. Benchekroun, M. Bender, K. Bendtz, N. Benekos, Y. Benhammou, E. Benhar Noccioli, J. Benitez, D. Benjamin, J. Bensinger, S. Bentvelsen, L. Beresford, M. Beretta, D. Berge, E. Bergeaas Kuutmann, N. Berger, J. Beringer, S. Berlendis, N.R. Bernard, C. Bernius, F.U. Bernlochner, W. Bernreuther, T. Berry, P. Berta, C. Bertella, G. Bertoli, F. Bertolucci, I.A. Bertram, C. Bertsche, D. Bertsche, G. Besjes, O. Bessidskaia Bylund, M.F. Bessner, N. Besson, C. Betancourt, A. Bethani, S. Bethke, A.J. Bevan, R. Bianchi, M. Bianco, O. Biebel, D. Biedermann, R. Bielski, N.V. Biesuz, M. Biglietti, J. Bilbao De Mendizabal, T.R.V. Billoud, H. Bilokon, M. Bindi, A. Bingul, C. Bini, S. Biondi, T. Bisanz, D.M. Bjergaard, C. Black, J. Black, K. Black, D. Blackburn, R. Blair, T. Blazek, I. Bloch, C. Blocker, A. Blue, W. Blum, U. Blumenschein, S. Blunier, G. Bobbink, V. Bobrovnikov, S.S. Bocchetta, A. Bocci, C. Bock, M. Boehler, D. Boerner, J.A. Bogaerts, D. Bogavac, A. Bogdanchikov, C. Bohm, V. Boisvert, P. Bokan, T. Bold, A. Boldyrev, M. Bomben, M. Bona, M. Boonekamp, A. Borisov, G. Borissov, J. Bortfeldt, D. Bortoletto, V. Bortolotto, K. Bos, D. Boscherini, M. Bosman, J.D. Bossio Sola, J. Boudreau, J. Bouffard, E.V. Bouhova Thacker, D.E. Boumediene, C. Bourdarios, S.K. Boutle, A. Boveia, J. Boyd, I. Boyko, J. Bracin

Abstract:

Measurements of top quark spin observables in tt¯ events are presented based on 20.2 fb−1 of s=8 TeV proton-proton collisions recorded with the ATLAS detector at the LHC. The analysis is performed in the dilepton final state, characterised by the presence of two isolated leptons (electrons or muons). There are 15 observables, each sensitive to a different coefficient of the spin density matrix of tt¯ production, which are measured independently. Ten of these observables are measured for the first time. All of them are corrected for detector resolution and acceptance effects back to the parton and stable-particle levels. The measured values of the observables at parton level are compared to Standard Model predictions at next-to-leading order in QCD. The corrected distributions at stable-particle level are presented and the means of the distributions are compared to Monte Carlo predictions. No significant deviation from the Standard Model is observed for any observable.[

Tipologia IRIS:

01 - Articolo su periodico

Keywords:

p p: colliding beams; top: pair production; final state: ((n)jet dilepton); top: spin; p p: scattering; detector: resolution; spin: density matrix; perturbation theory: higher-order; higher-order: 1 ; parton; ATLAS; quantum chromodynamics: perturbation theory; CERN LHC Coll; numerical calculations: Monte Carlo; acceptance; experimental results; 8000 GeV-cms; Hadron-Hadron scattering (experiments)

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