Characterization of the quantum state of top quark pairs produced in proton-proton collisions at s = 13 TeV using the beam and helicity bases

Physical review. D/Physical review. D. 2026 Open access

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Authors: A. Hayrapetyan, V. Makarenko, A. Tumasyan, W. Adam, L. Benato, T. Bergauer, M. Dragicevic, P. S. Hussain, M. Jeitler, N. Krammer, A. Li, D. Liko
+88 more M. Matthewman, Jochen Schieck, R. Schöfbeck, Maryam Shooshtari, M. Sonawane, W. Waltenberger, C.-E. Wulz, T. Janssen, H. Kwon, D. Ocampo Henao, T. Van Laer, P. Van Mechelen, Jas Bierkens, Nordin Breugelmans, J. D’Hondt, Soumya Dansana, A. De Moor, M. Delcourt, Felix Heyen, Y. Hong, Pavlo Kashko, S. Lowette, I. Makarenko, D. Müller, Stefaan Tavernier, Michael Tytgat, G. P. Van Onsem, S. Van Putte, David Vannerom, B. Bilin, B. Clerbaux, A. K. Das, I. De Bruyn, G. De Lentdecker, Hugues Evard, L. Favart, P. Gianneios, A. Khalilzadeh, F. A. Khan, Andrea Malara, M. A. Shahzad, A. Sharma, L. Thomas, M. Vanden Bemden, C. Vander Velde, P. Vanlaer, F. Zhang, M. De Coen, D. Dobur, C. Giordano, G. Gökbulut, K. Kaspar, D. Kavtaradze, David Marckx, K. Skovpen, A. M. Tomaru, N. Van Den Bossche, J. van der Linden, J. Vandenbroeck, H. Aarup Petersen, S. Bein, A. Benecke, Agni Bethani, G. Bruno, Alessandra Cappati, J. De Favereau De Jeneret, C. Delaere, F. Gameiro Casalinho, ANDREA GIAMMANCO, A. O. Guzel, V. Lemaitre, J. Lidrych, Paul Malek, Paola Mastrapasqua, S. Turkcapar, G. A. Alves, M. Barroso Ferreira Filho, E.A. Coelho, C. Hensel, D. Matos Figueiredo, T. Menezes De Oliveira, C. Mora Herrera, P. Rebello Teles, M. Soeiro, E. J. Tonelli Manganote, A. Vilela Pereira, W. L. Aldá Júnior, H. Brandao Malbouisson
DOI: 10.1103/hkgw-dztk
Cited by: 1
References: 47

Abstract

Measurements of the spin correlation coefficients in the beam basis are presented for top quark-antiquark ( t t ¯ ) systems produced in proton-proton collisions at s = 13 TeV collected by the CMS experiment in 2016–2018, and corresponding to an integrated luminosity of 138 fb − 1 . The t t ¯ system is reconstructed from final states containing an electron or muon and jets. Together with the previously reported results in the helicity basis, these measurements are used to decompose the system into the Bell and spin eigenstates in various kinematic regions. The spin correlation coefficients are also used to evaluate properties of the t t ¯ quantum state, such as the purity, von Neumann entropy, and entanglement. All results are consistent with standard model predictions.

Fields of Study & Subjects

High-Energy Particle Collisions Research Particle physics theoretical and experimental studies Quantum Chromodynamics and Particle Interactions

Publication details

Journal / source
Physical review. D/Physical review. D.
Publisher
American Physical Society (APS)
Volume
113
Issue
5
Publication date
29 January 2026
Language
EN