TAPIA, SEBASTIAN

2024-07-01, Aad, G., Abbott, B., Abeling, K., Abicht, N. J., Abidi, S. H., Aboulhorma, A., Abramowicz, H., Abreu, H., Abulaiti, Y., Acharya, B. S., Adam Bourdarios, C., Adamczyk, L., Adamek, L., Addepalli, S. V., 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., Aizenberg, I., Akbiyik, M., Åkesson, T. P.A., Akimov, A. V., Akiyama, D., Akolkar, N. N., Al Khoury, K., Alberghi, G. L., Albert, J., Albicocco, P., Albouy, G. L., Alderweireldt, S., 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., 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., Amor Dos Santos, S. P., Amos, K. R., 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., Anthony, M. T., Antipov, E., Antonelli, M., Anulli, F., Aoki, M., Aoki, T., Aparisi Pozo, J. A., Aparo, M. A., Aperio Bella, L., BROOKS, WILLIAM K., CARQUIN, EDSON, Fernandez Luengo, S.I., PEZOA, RAQUEL, Carolina Robles Gajardo, TAPIA, SEBASTIAN, VIAUX MAIRA, NICOLAS

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.

2024-07-01, Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N. J., Abidi, S. H., Aboelela, M., Aboulhorma, A., Abramowicz, H., Abreu, H., Abulaiti, Y., Acharya, B. S., Ackermann, A., Adam Bourdarios, C., Adamczyk, L., Addepalli, S. V., 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., CARQUIN, EDSON, Fernandez Luengo, S.I., Fuenzalida Garrido, S., PEZOA, RAQUEL, Carolina Robles Gajardo, TAPIA, SEBASTIAN, VIAUX MAIRA, NICOLAS

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

2024-03-08, 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., 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., Cristian Andres Allendes Flores, BROOKS, WILLIAM K., CARQUIN, EDSON, Fernandez Luengo, S.I., Fuenzalida Garrido, S., PEZOA, RAQUEL, Robles Gajardo, C.M., TAPIA, SEBASTIAN, Viaux Maira, N.

ATLAS measured the centrality dependence of the dijet yield using 165  nb−1 of 𝑝+Pb data collected at √𝑠NN=8.16  TeV in 2016. The event centrality, which reflects the 𝑝+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, 𝑅CP, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The 𝑅CP shows a scaling with the Bjorken 𝑥 of the parton originating from the proton, 𝑥𝑝, while no such trend is observed as a function of 𝑥Pb. This analysis provides unique input to understanding the role of small proton spatial configurations in 𝑝+Pb collisions by covering parton momentum fractions from the valence region down to 𝑥𝑝∼10−3 and 𝑥Pb∼4×10−4.