Now showing 1 - 3 of 3
  • Publication
    Azimuthal Angle Correlations of Muons Produced via Heavy-Flavor Decays in 5.02 TeV Pb+Pb and pp Collisions with the ATLAS Detector
    (2024-05-17)
    Filmer, E. K.
    ;
    Grant, C. M.
    ;
    Jackson, P.
    ;
    Kong, A. X.Y.
    ;
    Pandya, H. D.
    ;
    Potti, H.
    ;
    Ruggeri, T. A.
    ;
    Ting, E. X.L.
    ;
    White, M. J.
    ;
    Gingrich, D. M.
    ;
    Lindon, J. H.
    ;
    Nishu, N.
    ;
    Pinfold, J. L.
    ;
    Cakir, O.
    ;
    Yildiz, H. Duran
    ;
    Kuday, S.
    ;
    Turk Cakir, I.
    ;
    Sultansoy, S.
    ;
    Adam Bourdarios, C.
    ;
    Arnaez, O.
    ;
    Berger, N.
    ;
    Castillo, F. L.
    ;
    Costanza, F.
    ;
    Delmastro, M.
    ;
    Di Ciaccio, L.
    ;
    Hryn’ova, T.
    ;
    Jézéquel, S.
    ;
    Koletsou, I.
    ;
    Levêque, J.
    ;
    Lewis, D. J.
    ;
    Little, J. D.
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    Lorenzo Martinez, N.
    ;
    Poddar, G.
    ;
    Sanchez Pineda, A.
    ;
    Sauvan, E.
    ;
    Bernardi, G.
    ;
    Bomben, M.
    ;
    Li, A.
    ;
    Li, T.
    ;
    Marchiori, G.
    ;
    Nakkalil, K.
    ;
    Shen, Q.
    ;
    Zhang, Y.
    ;
    Chekanov, S.
    ;
    Darmora, S.
    ;
    Hopkins, W. H.
    ;
    Hoya, J.
    ;
    Love, J.
    ;
    Luongo, N. A.
    ;
    Metcalfe, J.
    ;
    Mete, A. S.
    ;
    Paramonov, A.
    ;
    Proudfoot, J.
    ;
    Van Gemmeren, P.
    ;
    Wamorkar, T.
    ;
    Wang, R.
    ;
    Zhang, J.
    ;
    Cheu, E.
    ;
    Cui, Z.
    ;
    Ghosh, A.
    ;
    Johns, K. A.
    ;
    Lampl, W.
    ;
    Lindley, R. E.
    ;
    Loch, P.
    ;
    Rutherfoord, J. P.
    ;
    Sardain, J.
    ;
    Varnes, E. W.
    ;
    Zhou, H.
    ;
    Zhou, Y.
    ;
    Bakshi Gupta, D.
    ;
    Burghgrave, B.
    ;
    Cardenas, J. C.J.
    ;
    De, K.
    ;
    Farbin, A.
    ;
    Hadavand, H. K.
    ;
    Myers, A. J.
    ;
    Ozturk, N.
    ;
    Usai, G.
    ;
    White, A.
    ;
    Angelidakis, S.
    ;
    Fassouliotis, D.
    ;
    Fountas, L.
    ;
    Gkialas, I.
    ;
    Kourkoumelis, C.
    ;
    Alexopoulos, T.
    ;
    Drivas-Koulouris, I.
    ;
    Gazis, E. N.
    ;
    Kitsaki, C.
    ;
    Maltezos, S.
    ;
    Paraskevopoulos, C.
    ;
    Perganti, M.
    ;
    Tzanis, P.
    ;
    Andeen, T.
    ;
    Burton, C. D.
    ;
    Choi, K.
    ;
    Onyisi, P. U.E.
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    Panchal, D. K.
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    Tost, M.
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    Unal, M.
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    Huseynov, N.
    ;
    ; ; ;
    Fernandez Luengo, S.I.
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    Fuenzalida Garrido, S.
    ;
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    Carolina Robles Gajardo
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    Tapia Araya, S.
    ;
    Angular correlations between heavy quarks provide a unique probe of the quark-gluon plasma created in ultrarelativistic heavy-ion collisions. Results are presented of a measurement of the azimuthal angle correlations between muons originating from semileptonic decays of heavy quarks produced in 5.02 TeV Pb+Pb and 𝑝⁢𝑝 collisions at the LHC. The muons are measured with transverse momenta and pseudorapidities satisfying 𝑝𝜇T>4  GeV and |𝜂𝜇|<2.4, respectively. The distributions of azimuthal angle separation Δ⁢𝜙 for muon pairs having pseudorapidity separation |Δ⁢𝜂|>0.8, are measured in different Pb+Pb centrality intervals and compared to the same distribution measured in 𝑝⁢𝑝 collisions at the same center-of-mass energy. Results are presented separately for muon pairs with opposite-sign charges, same-sign charges, and all pairs. A clear peak is observed in all Δ⁢𝜙 distributions at Δ⁢𝜙∼𝜋, consistent with the parent heavy-quark pairs being produced via hard-scattering processes. The widths of that peak, characterized using Cauchy-Lorentz fits to the Δ⁢𝜙 distributions, are found to not vary significantly as a function of Pb+Pb collision centrality and are similar for 𝑝⁢𝑝 and Pb+Pb collisions. This observation will provide important constraints on theoretical descriptions of heavy-quark interactions with the quark-gluon plasma.
  • Publication
    Measurement of t-channel single-top-quark production in pp collisions at s=5.02 TeV with the ATLAS detector
    (2024-07-01)
    Aad, G.
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    Abbott, B.
    ;
    Abeling, K.
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    Abicht, N. J.
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    Abidi, S. H.
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    Aboulhorma, A.
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    Abramowicz, H.
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    Abreu, H.
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    Abulaiti, Y.
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    Acharya, B. S.
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    Adam Bourdarios, C.
    ;
    Adamczyk, L.
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    Adamek, L.
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    Addepalli, S. V.
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    Addison, M. J.
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    Adelman, J.
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    Adiguzel, A.
    ;
    Adye, T.
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    Affolder, A. A.
    ;
    Afik, Y.
    ;
    Agaras, M. N.
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    Agarwala, J.
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    Aggarwal, A.
    ;
    Agheorghiesei, C.
    ;
    Ahmad, A.
    ;
    Ahmadov, F.
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    Ahmed, W. S.
    ;
    Ahuja, S.
    ;
    Ai, X.
    ;
    Aielli, G.
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    Aikot, A.
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    Ait Tamlihat, M.
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    Aitbenchikh, B.
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    Aizenberg, I.
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    Akbiyik, M.
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    Åkesson, T. P.A.
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    Akimov, A. V.
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    Akiyama, D.
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    Akolkar, N. N.
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    Al Khoury, K.
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    Alberghi, G. L.
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    Albert, J.
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    Albicocco, P.
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    Albouy, G. L.
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    Alderweireldt, S.
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    Aleksa, M.
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    Aleksandrov, I. N.
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    Alexa, C.
    ;
    Alexopoulos, T.
    ;
    Alfonsi, F.
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    Algren, M.
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    Alhroob, M.
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    Ali, B.
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    Ali, H. M.J.
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    Ali, S.
    ;
    Alibocus, S. W.
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    Aliev, M.
    ;
    Alimonti, G.
    ;
    Alkakhi, W.
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    Allaire, C.
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    Allbrooke, B. M.M.
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    Allen, J. F.
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    Allendes Flores, C. A.
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    Allport, P. P.
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    Aloisio, A.
    ;
    Alonso, F.
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    Alpigiani, C.
    ;
    Alvarez Estevez, M.
    ;
    Alvarez Fernandez, A.
    ;
    Alves Cardoso, M.
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    Alviggi, M. G.
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    Aly, M.
    ;
    Amaral Coutinho, Y.
    ;
    Ambler, A.
    ;
    Amelung, C.
    ;
    Amerl, M.
    ;
    Ames, C. G.
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    Amidei, D.
    ;
    Amor Dos Santos, S. P.
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    Amos, K. R.
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    Ananiev, V.
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    Anastopoulos, C.
    ;
    Andeen, T.
    ;
    Anders, J. K.
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    Andrean, S. Y.
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    Andreazza, A.
    ;
    Angelidakis, S.
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    Angerami, A.
    ;
    Anisenkov, A. V.
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    Annovi, A.
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    Antel, C.
    ;
    Anthony, M. T.
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    Antipov, E.
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    Antonelli, M.
    ;
    Anulli, F.
    ;
    Aoki, M.
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    Aoki, T.
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    Aparisi Pozo, J. A.
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    Aparo, M. A.
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    Aperio Bella, L.
    ;
    ; ;
    Fernandez Luengo, S.I.
    ;
    ;
    Carolina Robles Gajardo
    ;
    ;
    The observation of the electroweak production of single-top-quarks is made using 255 pb−1 of proton-proton collision data recorded at s√=5.02 TeV with the ATLAS detector at the Large Hadron Collider. An event selection is used to identify single-top-quark candidates arising from t-channel production with the top quark decaying semi-leptonically. Events passing the selection are then used to measure the inclusive cross-section for the combined production of single-top-quarks and antiquarks, σ(tq+t¯q), and the ratio Rt between these two. They are measured to be σ(tq+t¯q)=27.1+4.4−4.1(stat.)+4.4−3.7(syst.) pb and Rt=2.73+1.43−0.82(stat.)+1.01−0.29(syst.). The individual single-top-quark (tq) and single-top-antiquark (t¯q) production cross-sections are measured to be σ(tq)=19.8+3.9−3.1(stat.)+2.9−2.2(syst.) pb and σ(t¯q)=7.3+3.2−2.1(stat.)+2.8−1.5(syst.) pb. All measurements are in good agreement with the Standard Model predictions.
  • Publication
    Measurement of vector boson production cross sections and their ratios using pp collisions at s=13.6 TeV with the ATLAS detector
    (2024-07-01)
    Aad, G.
    ;
    Aakvaag, E.
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    Abbott, B.
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    Abdelhameed, S.
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    Abeling, K.
    ;
    Abicht, N. J.
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    Abidi, S. H.
    ;
    Aboelela, M.
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    Aboulhorma, A.
    ;
    Abramowicz, H.
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    Abreu, H.
    ;
    Abulaiti, Y.
    ;
    Acharya, B. S.
    ;
    Ackermann, A.
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    Adam Bourdarios, C.
    ;
    Adamczyk, L.
    ;
    Addepalli, S. V.
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    Addison, M. J.
    ;
    Adelman, J.
    ;
    Adiguzel, A.
    ;
    Adye, T.
    ;
    Affolder, A. A.
    ;
    Afik, Y.
    ;
    Agaras, M. N.
    ;
    Agarwala, J.
    ;
    Aggarwal, A.
    ;
    Agheorghiesei, C.
    ;
    Ahmad, A.
    ;
    Ahmadov, F.
    ;
    Ahmed, W. S.
    ;
    Ahuja, S.
    ;
    Ai, X.
    ;
    Aielli, G.
    ;
    Aikot, A.
    ;
    Ait Tamlihat, M.
    ;
    Aitbenchikh, B.
    ;
    Akbiyik, M.
    ;
    Åkesson, T. P.A.
    ;
    Akimov, A. V.
    ;
    Akiyama, D.
    ;
    Akolkar, N. N.
    ;
    Aktas, S.
    ;
    Al Khoury, K.
    ;
    Alberghi, G. L.
    ;
    Albert, J.
    ;
    Albicocco, P.
    ;
    Albouy, G. L.
    ;
    Alderweireldt, S.
    ;
    Alegria, Z. L.
    ;
    Aleksa, M.
    ;
    Aleksandrov, I. N.
    ;
    Alexa, C.
    ;
    Alexopoulos, T.
    ;
    Alfonsi, F.
    ;
    Algren, M.
    ;
    Alhroob, M.
    ;
    Ali, B.
    ;
    Ali, H. M.J.
    ;
    Ali, S.
    ;
    Alibocus, S. W.
    ;
    Aliev, M.
    ;
    Alimonti, G.
    ;
    Alkakhi, W.
    ;
    Allaire, C.
    ;
    Allbrooke, B. M.M.
    ;
    Allen, J. F.
    ;
    Allendes Flores, C. A.
    ;
    Allport, P. P.
    ;
    Aloisio, A.
    ;
    Alonso, F.
    ;
    Alpigiani, C.
    ;
    Alsolami, Z. M.K.
    ;
    Alvarez Estevez, M.
    ;
    Alvarez Fernandez, A.
    ;
    Alves Cardoso, M.
    ;
    Alviggi, M. G.
    ;
    Aly, M.
    ;
    Amaral Coutinho, Y.
    ;
    Ambler, A.
    ;
    Amelung, C.
    ;
    Amerl, M.
    ;
    Ames, C. G.
    ;
    Amidei, D.
    ;
    Amirie, K. J.
    ;
    Amor Dos Santos, S. P.
    ;
    Amos, K. R.
    ;
    An, S.
    ;
    Ananiev, V.
    ;
    Anastopoulos, C.
    ;
    Andeen, T.
    ;
    Anders, J. K.
    ;
    Andrean, S. Y.
    ;
    Andreazza, A.
    ;
    Angelidakis, S.
    ;
    Angerami, A.
    ;
    Anisenkov, A. V.
    ;
    Annovi, A.
    ;
    Antel, C.
    ;
    Antipov, E.
    ;
    Antonelli, M.
    ;
    ;
    Fernandez Luengo, S.I.
    ;
    Fuenzalida Garrido, S.
    ;
    ;
    Carolina Robles Gajardo
    ;
    ;
    Fiducial and total 𝑊 ± and 𝑍 boson cross sections, their ratios and the ratio of top-antitop-quark pair and 𝑊 -boson fiducial cross sections are measured in proton–proton collisions at a centre-of-mass energy of √𝑠 = 13.6 TeV, corresponding to an integrated luminosity of 29 fb−1 of data collected in 2022 by the ATLAS experiment at the Large Hadron Collider. The measured fiducial cross-section values for 𝑊 + → 𝓁+𝜈, 𝑊 − → 𝓁−𝜈̄, and 𝑍 → 𝓁+𝓁− (𝓁 = 𝑒 or 𝜇) boson productions are 4250 ± 150 pb, 3310 ± 120 pb, and 744 ± 20 pb, respectively, where the uncertainty is the total uncertainty, including that arising from the luminosity of about 2.2%. The measurements are in agreement with Standard-Model predictions calculated at next-to-next-to-leading-order in 𝛼𝑠 , next-to-nextto-leading logarithmic accuracy and next-to-leading-order electroweak accuracy