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Exploring Tidal Force Effects and Shadow Constraints for Schwarzschild-like Black Hole in Starobinsky-Bel-Robinson Gravity

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arXiv 2023年

作者： Arora, Dhruv Molla, Niyaz Uddin Chaudhary, Himanshu Debnath, Ujjal Atamurotov, Farruh Mustafa, G. Sagara Odisha Sambalpur768224 India Department of Mathematics Indian Institute of Engineering Science and Technology Shibpur Howrah711 103 India Department of Applied Mathematics Delhi Technological University Delhi110042 India Department of Mathematics Shyamlal College University of Delhi Delhi110032 India New Uzbekistan University Mustaqillik ave. 54 Tashkent100007 Uzbekistan Central Asian University Milliy Bog’ Street 264 Tashkent111221 Uzbekistan Faculty of Computer Engineering Tashkent University of Applied Sciences Gavhar Str. 1 Tashkent100149 Uzbekistan Institute of Theoretical Physics National University of Uzbekistan Tashkent100174 Uzbekistan Department of Physics Zhejiang Normal University Jinhua321004 China Zhejiang Institute of Photoelectronics Zhejiang Institute for Advanced Light Source Zhejiang Normal University Zhejiang Jinhua321004 China

The current manuscript deals with the tidal force effects, geodesic deviation, and shadow constraints of the Schwarzschild-like black hole theorised in Starobinsky-Bel-Robinson gravity exhibiting M-theory compactification. In the current analysis, we explore the radial and angular tidal force effects on a radially in-falling particle by the central black hole, which is located in this spacetime. We also numerically solve the geodesic deviation equation and study the variation of the geodesic separation vector with the radial coordinate for two nearby geodesics using suitable initial conditions. All the obtained results are tested for Sag A* and M87* by constraining the value of the stringy gravity parameter β using the shadow data from the event horizon telescope observations. All the results are compared with Schwarzschild black hole spacetime. In our study, we found that both the radial and angular tidal forces experienced by a particle switch their initial behaviour and turn compressive and stretching, respectively, before reaching the event horizon. The geodesic deviation shows an oscillating trend as well for the chosen initial condition. For the constrained value of β, we see that the spacetime geometry generated by Sag A* and M87* is effectively same for both Schwarzschild and Starobinsky-Bel-Robinson black hole. Furthermore, we also calculated the angular diameter of the shadow in Starobinsky-Bel-Robinson black hole and compared with the Schwarzschild black hole. It is observed that the angular diameter of shadow for M87* and Sgr A* in Starobinsky-Bel-Robinson black hole is smaller than the Schwarzschild black hole. The calculated results satisfy the event horizon telescope observational constraints. Copyright © 2023, The Authors. All rights reserved.

关键词： Black holes

Measurements of high-n transitions in intermediate mass kaonic atoms by SIDDHARTA-2 at DAΦNE

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arXiv 2023年

作者： Sgaramella, F. Tüchler, M. Amsler, C. Bazzi, M. Bosnar, D. Bragadireanu, M. Cargnelli, M. Carminati, M. Clozza, A. Deda, G. Del Grande, R. De Paolis, L. Fabbietti, L. Fiorini, C. Friščić, I. Guaraldo, C. Iliescu, M. Iwasaki, M. Khreptak, A. Manti, S. Marton, J. Miliucci, M. Moskal, P. Napolitano, F. Niedźwiecki, S. Ohnishi, H. Piscicchia, K. Sada, Y. Scordo, A. Shi, H. Silarski, M. Sirghi, D. Sirghi, F. Skurzok, M. Spallone, A. Toho, K. Vazquez Doce, O. Widmann, E. Yoshida, C. Zmeskal, J. Curceanu, C. INFN-LNF Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati Frascati Roma00044 Italy Stefan-Meyer-Institut für Subatomare Physik Vienna1030 Austria University of Vienna Vienna Doctoral School in Physics Vienna1090 Austria Department of Physics Faculty of Science University of Zagreb Zagreb10000 Croatia Horia Hulubei National Institute of Physics and Nuclear Engineering IFIN-HH Magurele Romania Politecnico di Milano Dipartimento di Elettronica Informazione e Bioingegneria Milano20133 Italy INFN Sezione di Milano 20133 Italy Physik Department E62 Technische Universität München Garching85748 Germany RIKEN Tokyo351-0198 Japan Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland Center for Theranostics Jagiellonian University Krakow Poland Tohoku University Sendai982-0826 Japan Centro Ricerche Enrico Fermi Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" Roma00184 Italy

The SIDDHARTA-2 experiment installed at the DAΦNE collider of INFN-LNF performed, for the first time, measurements of high-n transitions in intermediate mass kaonic atoms during the data taking campaigns of 2021 and 2022. Kaonic carbon, oxygen, nitrogen and aluminium transitions, which occur in the setup materials, were measured by using the kaons stopped in the gaseous helium target cell with aluminium frames and Kapton walls, and are reported in this paper. These new kaonic atoms measurements add valuable input to the kaonic atoms transitions data base, which is used as a reference for theories and models of the low-energy strong interaction between antikaon and nuclei. Moreover, these results pave the way for future dedicated kaonic atoms measurements through the whole periodic table and to a new era for the antikaon-nuclei studies at low energy. © 2023, CC BY.

关键词： Aluminum

Coexisting magnetic structures and spin-reorientation in Er0.5Dy0.5FeO3: Bulk magnetization, neutron scattering, specific heat, and Ab-initio studies

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arXiv 2021年

作者： Rajput, Sarita Balasubramanian, Padmanabhan Singh, Ankita Damay, Francoise Kumar, C.M.N. Tabis, W. Maitra, T. Malik, Vivek K. Department of Physics Indian Institute of Technology Roorkee Roorkee247 667 India Department of Physics Graphic Era University Uttarakhand Dehra Dun248 002 India Laboratoire Léon Brillouin CEA-CNRS CEA/Saclay Gif sur Yvette91191 France Institute of Solid State Physics Vienna University of Technology Wiedner Hauptstrasse 8-10 Wien1040 Austria AGH University of Science and Technology Faculty of Physics and Applied Computer Science Kraków30-059 Poland

The complex magnetic structures, spin-reorientation and associated exchange interactions have been investigated in Er0.5Dy0.5FeO3 using bulk magnetization, neutron diffraction, specific heat measurements and density functional theory calculations. The Fe3+ spins order as G-type antiferromagnet structure depicted by Γ4(Gx, Ay, Fz) irreducible representation below 700 K, similar to its end compounds. The bulk magnetization data indicate occurrence of the spin-reorientation and rare-earth magnetic ordering below ∼75 K and 10 K, respectively. The neutron diffraction studies confirm an "incomplete" Γ4→ Γ2(Fx, Cy, Gz) spin-reorientation initiated ≤75 K. Although, the relative volume fraction of the two magnetic structures varies with decreasing temperature, both co-exist even at 1.5 K. Below 10 K, magnetic ordering of Er3+/Dy3+ moments in cRy arrangement develops, which gradually increases in intensity with decreasing temperature. At 2 K, magnetic structure associated with cRz arrangement of Er3+/Dy3+ moments also appears. At 1.5 K the magnetic structure of Fe3+ spins is represented by a combination of Γ2+Γ4+Γ1, while the rare earth magnetic moments’ order coexists as cRy and cRz corresponding to Γ2 and Γ1 representation, respectively. The observed Schottky anomaly at 2.5 K suggests that the "rare-earth ordering" is induced by polarization due to Fe3+ spins. The Er3+-Fe3+ and Er3+-Dy3+ exchange interactions, obtained from first principle calculations, indicate that these interactions primarily cause the complicated spin-reorientation and cRy rare-earth ordering in the system, respectively, while the dipolar interactions between rare-earth moments, result in the cRz type rare-earth ordering at 2 K. Copyright © 2021, The Authors. All rights reserved.

关键词： Rare earths

Numerical investigation of gas hydrate dissociation in the porous medium of multiphase flow

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AIP Conference Proceedings 2023年第1期2872卷

作者： Ahmed K. Abu-Nab Alexander V. Koldoba Elena V. Koldoba Yury A. Poveshchenko Viktoriia O. Podryga Parvin I. Rahimly Ahmed E. Bakeer Department of Mathematics and Computer Science Faculty of Science Menoufia University Shebin El-Koom 32511 Egypt Phystech School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Dolgoprudny Moscow 141700 Russia Lomonosov Moscow State University Moscow 119991 Russia Keldysh Institute of Applied Mathematics Russian Academy of Sciences Moscow 125047 Russia Department of Mathematics Faculty of Science Damanhur University Damanhur 22516 Egypt

Understanding the mechanisms involved in the growth and decomposition of methane hydrates (MHs) is currently an urgent issue since they are essential in improving the global climate and future energy supplies. As a result, many scientists and researchers around the world are looking into and studying this critical topic. The objective of the presented work is to illustrate the thermo-physical processes of MHs decomposition in porous media based on a one-dimensional model throughout a multiphase flow. The thermodynamic equilibrium, which actually happens between temperature and pressure (P-T) in the hydrate stability region. The mathematical model was presented and solved by using the implicit finite differences technique under the initial and boundary conditions. After the Jacobin matrix was formed, the system of nonlinear algebraic equations was solved by using the Newton-Raphson methodology. Within the framework of this study, we take into consideration the Buckley-Leverett problem of incompressible fluid displacement. Our approach and computations are predicated on the assumption that there are constant heat conditions without hydrate formation anywhere in the whole computational domain.

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Engineering Phase Competition Between Stripe Order and Superconductivity in La1.88Sr0.12CuO4

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arXiv 2023年

作者： Küspert, J. Lo, I. Bia Frison, R. Morawietz, A. Martinelli, L. Choi, J. Bucher, D. Ivashko, O. Zimmermann, M.V. Christensen, N.B. Mazzone, D.G. Simutis, G. Turrini, A.A. Thomarat, L. Tam, D.W. Janoschek, M. Kurosawa, T. Momono, N. Oda, M. Wang, Qisi Chang, J. Physik-Institut Universität Zürich Winterthurerstrasse 190 ZürichCH-8057 Switzerland AGH University of Krakow Faculty of Physics and Applied Computer Science Krakow30-059 Poland Diamond Light Source Harwell Campus DidcotOX11 0DE United Kingdom Deutsches Elektronen-Synchrotron DESY Notkestraße 85 Hamburg22607 Germany Department of Physics Technical University of Denmark Kongens LyngbyDK-2800 Denmark Laboratory for Neutron Scattering and Imaging Paul Scherrer Institut Villigen-PSI CH-5232 Switzerland Laboratory for Neutron and Muon Instrumentation Paul Scherrer Institut Villigen PSICH-5232 Switzerland École normale supérieure Paris-Saclay Gif-sur-Yvette91190 France Department of Physics Hokkaido University Sapporo060-0810 Japan Department of Applied Sciences Muroran Institute of Technology Muroran050-8585 Japan Department of Physics The Chinese University of Hong Kong Shatin Hong Kong

Unconventional superconductivity often couples to other electronic orders in a cooperative or competing fashion. Identifying external stimuli that tune between these two limits is of fundamental interest. Here, we show that strain perpendicular to the copper-oxide planes couples directly to the competing interaction between charge stripe order and superconductivity in La1.88Sr0.12CuO4 (LSCO). Compressive c-axis pressure amplifies stripe order within the superconducting state, while having no impact on the normal state. By contrast, strain dramatically diminishes the magnetic field enhancement of stripe order in the superconducting state. These results suggest that c-axis strain acts as tuning parameter of the competing interaction between charge stripe order and superconductivity. This interpretation implies a uniaxial pressure-induced ground state in which the competition between charge order and superconductivity is reduced. © 2023, CC BY.

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Weak-signal extraction enabled by deep-neural-network denoising of diffraction data

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arXiv 2022年

作者： Oppliger, J. Denner, M.M. Küspert, J. Frison, R. Wang, Q. Morawietz, A. Ivashko, O. Dippel, A.-C. Zimmermann, M.V. Bialo, I. Martinelli, L. Fauqué, B. Choi, J. Garcia-Fernandez, M. Zhou, K.-J. Christensen, N.B. Kurosawa, T. Momono, N. Oda, M. Natterer, F.D. Fischer, M.H. Neupert, T. Chang, J. Physik-Institut Universität Zürich Winterthurerstrasse 190 ZürichCH-8057 Switzerland Department of Physics The Chinese University of Hong Kong Shatin Hong Kong Deutsches Elektronen-Synchrotron DESY Notkestraße 85 Hamburg22607 Germany AGH University of Science and Technology Faculty of Physics and Applied Computer Science Kraków30-059 Poland JEIP USR 3573 CNRS Collège de France PSL University 11 place Marcelin Berthelot Paris75231 Cedex 05 France Diamond Light Source Harwell Campus Didcot OxfordshireOX11 0DE United Kingdom Department of Physics Technical University of Denmark Kongens LyngbyDK-2800 Denmark Department of Physics Hokkaido University Sapporo060-0810 Japan Department of Applied Sciences Muroran Institute of Technology Muroran050-8585 Japan

Removal or cancellation of noise has wide-spread applications for imaging and acoustics. In every-day-life applications, denoising may even include generative aspects, which are unfaithful to the ground truth. For scientific use, however, denoising must reproduce the ground truth accurately. Here, we show how data can be denoised via a deep convolutional neural network such that weak signals appear with quantitative accuracy. In particular, we study X-ray diffraction on crystalline materials. We demonstrate that weak signals stemming from charge ordering, insignificant in the noisy data, become visible and accurate in the denoised data. This success is enabled by supervised training of a deep neural network with pairs of measured low- and high-noise data. We demonstrate that using artificial noise does not yield such quantitatively accurate results. Our approach thus illustrates a practical strategy for noise filtering that can be applied to challenging acquisition problems. Copyright © 2022, The Authors. All rights reserved.

关键词： Deep neural networks

Mathematical modelling and projection of Buruli ulcer transmission dynamics using classical and fractional derivatives: A case study of Cameroon

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Partial Differential Equations in applied Mathematics 2023年 8卷

作者： Fandio, Rubin Abboubakar, Hamadjam Fouda, Henri Paul Ekobena Kumar, Anoop Nisar, Kottakkaran Sooppy The University of Yaoundé I Laboratory of Biophysics P.O. Box 812 Cameroon The University of Ngaoundéré University Institute of Technology Department of Computer Engineering P.O. Box 455 Ngaoundéré Cameroon The University of Yaoundé I Faculty of Science Department of Physics P.O. Box 812 Cameroon Central University of Punjab School of Basic and Applied Sciences Department of Mathematics and Statistics Bathinda Punjab 151001 India Department of Mathematics College of Science and Humanities in Alkharj Prince Sattam Bin Abdulaziz University Alkharj 11942 Saudi Arabia

The goal of this work is to derive and study a new model which traduces the transmission dynamics of the Buruli ulcer (BU), in which we replace mass action incidences with standard incidences, consider latent period, and by using both integer and fractional derivatives. We first present reported data of Buruli in Cameroon between 01/01/2001 and 31/12/2014, and the statistical model that approximates real data as closely as possible, and thus make a forecasting in the next sixteen years. After that, we formulate a Susceptible humans-Exposed humans-Infectious humans-Recovered humans-Susceptible humans;Susceptible vectors-Infectious vectors (SEIRS-SI) type compartmental model of Buruli Ulcer using integer derivative. We compute the basic reproduction number denoted by R₀ and prove the asymptotic stability of the Buruli-free equilibrium whenever R₀<1. Then, for R₀>1, we prove the existence of an unique endemic equilibrium point and its global stability using the general theory of Lyapunov. We perform parameter estimation to calibrate our model using real data from Cameroon, while sensitivity analysis is conducted to determine important parameters in the BU dynamics. From this model calibration, we obtain R₀=2.0843 which is greater than one and implies that BU ulcer is endemic in the country. To determine whether if or not the BU admits one or multiple waves, we compute the strength number denoted by A₀. We find that A₀≈17>0 which means that Bu admits multiple epidemic waves. We then replace integer derivative with the Caputo fractional derivative. Asymptotic stability of equilibrium points are also performed for the fractional model. This follows by the proof of existence and the uniqueness of solutions of the fractional model. We then construct a numerical scheme based on the Adams–Bashforth–Moulton (ABM) Method. Theoretical results are validated from numerical simulations. These last also permits to eva

关键词： Asymptotic stability Buruli ulcer Caputo derivative Parameter estimation Strength number

AtlFast3: The Next Generation of Fast Simulation in ATLAS

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Computing and Software for Big science 2022年第1期6卷 1-54页

作者： Aad, G. Abbott, B. Abbott, D.C. Abud, A. Abed Abeling, K. Abhayasinghe, D.K. Abidi, S.H. Aboulhorma, A. Abramowicz, H. Abreu, H. Abulaiti, Y. Hoffman, A. C. Abusleme Acharya, B.S. Achkar, B. Adam, L. Bourdarios, C. Adam Adamczyk, L. Adamek, L. Addepalli, S.V. Adelman, J. Adiguzel, A. Adorni, S. Adye, T. Affolder, A.A. Afik, Y. Agapopoulou, C. Agaras, M.N. Agarwala, J. Aggarwal, A. Agheorghiesei, C. Aguilar-Saavedra, J.A. Ahmad, A. Ahmadov, F. Ahmed, W.S. Ai, X. Aielli, G. Aizenberg, I. Akatsuka, S. Akbiyik, M. Åkesson, T.P.A. Akimov, A.V. Khoury, K. Al Alberghi, G.L. Albert, J. Albicocco, P. Verzini, M. J. Alconada Alderweireldt, S. Aleksa, M. Aleksandrov, I.N. Alexa, C. Alexopoulos, T. Alfonsi, A. Alfonsi, F. Alhroob, M. Ali, B. Ali, S. Aliev, M. Alimonti, G. Allaire, C. Allbrooke, B.M.M. Allport, P.P. Aloisio, A. Alonso, F. Alpigiani, C. Camelia, E. Alunno Estevez, M. Alvarez Alviggi, M.G. Coutinho, Y. Amaral Ambler, A. Ambroz, L. Amelung, C. Amidei, D. Santos, S. P. Amor Dos Amoroso, S. Amos, K.R. Amrouche, C.S. Ananiev, V. Anastopoulos, C. Andari, N. 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. Antrim, D.J.A. Anulli, F. Aoki, M. Pozo, J. A. Aparisi Aparo, M.A. Bella, L. Aperio Aranzabal, N. Ferraz, V. Araujo Arcangeletti, C. Arce, A.T.H. Arena, E. Arguin, J.-F. Argyropoulos, S. Arling, J.-H. Armbruster, A.J. Armstrong, A. Arnaez, O. Arnold, H. Tame, Z. P. Arrubarrena Artoni, G. Asada, H. Asai, K. Asai, S. Asbah, N.A. Asimakopoulou, E.M. Asquith, L. Assahsah, J. Assamagan, K. Astalos, R. Atkin, R.J. Atkinson, M. Atlay, N.B. Atmani, H. Atmasiddha, P.A. Augsten, K. Auricchio, S. Austrup, V.A. Avner, G. Avolio, G. Ayoub, M.K. Azuelos, G. Babal, D. Bachacou, H. Bachas, K. Bachiu, A. Backman, F. Badea, A. Bagnaia, P. Bahrasemani, H. Bailey, A.J. Bailey, V.R. Baines, J.T. Bakalis, C. Baker, O.K. Bakker, P.J. Bakos, E. Gupta, D. Bakshi Balaji, S. Balasubramanian, R. Baldin, E.M. Balek, P. Ballabene, E. Bal Department of Physics University of Adelaide Adelaide Australia Department of Physics University of Alberta Edmonton AB Canada Department of Physics Ankara University Ankara Turkey Division of Physics TOBB University of Economics and Technology Ankara Turkey LAPP Univ. Savoie Mont Blanc CNRS/IN2P3 Annecy France High Energy Physics Division Argonne National Laboratory Argonne IL United States Department of Physics University of Arizona Tucson AZ United States Department of Physics University of Texas at Arlington Arlington TX United States Physics Department National and Kapodistrian University of Athens Athens Greece Physics Department National Technical University of Athens Zografou Greece Department of Physics University of Texas at Austin Austin TX United States Bahcesehir University Faculty of Engineering and Natural Sciences Istanbul Turkey Istanbul Bilgi University Faculty of Engineering and Natural Sciences Istanbul Turkey Department of Physics Bogazici University Istanbul Turkey Department of Physics Engineering Gaziantep University Gaziantep Turkey Institut de Física d’Altes Energies (IFAE) Barcelona Institute of Science and Technology Barcelona Spain Institute of High Energy Physics Chinese Academy of Sciences Beijing China Physics Department Tsinghua University Beijing China Department of Physics Nanjing University Nanjing China University of Chinese Academy of Science (UCAS) Beijing China Institute of Physics University of Belgrade Belgrade Serbia Department for Physics and Technology University of Bergen Bergen Norway Physics Division Lawrence Berkeley National Laboratory and University of California Berkeley CA United States Institut für Physik Humboldt Universität zu Berlin Berlin Germany Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics University of Bern Bern Switzerland School of Physics and Astronomy University of Birmingham Birmingham United Kingdom Facultad de Ciencias y Cen

The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes. © 2022, Springer Nature Switzerland AG.

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Precise test of lepton flavour universality in -boson decays into muons and electrons in collisions at with the ATLAS detector

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The European Physical Journal C 2024年第10期84卷 1-33页

作者： 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. Bourdarios, C. Adam 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. Tamlihat, M. Ait Aitbenchikh, B. Akbiyik, M. Åkesson, T. P. A. Akimov, A. V. Akiyama, D. Akolkar, N. N. Aktas, S. Khoury, K. Al 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. Flores, C. A. Allendes Allport, P. P. Aloisio, A. Alonso, F. Alpigiani, C. Alsolami, Z. M. K. Estevez, M. Alvarez Fernandez, A. Alvarez Cardoso, M. Alves Alviggi, M. G. Aly, M. Coutinho, Y. Amaral Ambler, A. Amelung, C. Amerl, M. Ames, C. G. Amidei, D. Amirie, K. J. Santos, S. P. Amor Dos 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. Anulli, F. Aoki, M. Aoki, T. Aparo, M. A. Bella, L. Aperio Appelt, C. Apyan, A. Val, S. J. Arbiol Arcangeletti, C. Arce, A. T. H. Arena, E. Arguin, J.-F. Argyropoulos, S. Arling, J.-H. Arnaez, O. Arnold, H. Artoni, G. Asada, H. Asai, K. Asai, S. Asbah, N. A. Ashby Pickering, R. A. Assamagan, K. Astalos, R. Astrand, K. S. V. Atashi, S. Atkin, R. J. Atkinson, M. Atmani, H. Atmasiddha, P. A. Augsten, K. Auricchio, S. Auriol, A. D. Austrup, V. A. Avolio, G. Axiotis, K. Azuelos, G. Babal, D. Bachacou, H. Bachas, K. Bachiu, A. Backman, F. Badea, A. Baer, T. M. Bagnaia, P. Bahmani, M. Bahner, D. Bai, K. Baines, J. T. Baines, L. Baker, O. K. Bakos, E. Gupta, D. Bakshi Balakrishnan, V. Balasubr CPPM Aix-Marseille Université CNRS/IN2P3 Marseille France Department for Physics and Technology University of Bergen Bergen Norway Homer L. Dodge Department of Physics and Astronomy University of Oklahoma Norman USA New York University Abu Dhabi Abu Dhabi United Arab Emirates II. Physikalisches Institut Georg-August-Universität Göttingen Göttingen Germany Fakultät Physik Technische Universität Dortmund Dortmund Germany Physics Department Brookhaven National Laboratory Upton USA Physics Department Southern Methodist University Dallas USA Faculté des sciences Université Mohammed V Rabat Morocco Raymond and Beverly Sackler School of Physics and Astronomy Tel Aviv University Tel Aviv Israel Department of Physics Technion Israel Institute of Technology Haifa Israel Department of Physics New York University New York USA INFN Gruppo Collegato di Udine Sezione di Trieste Udine Italy ICTP Trieste Italy Department of Physics King’s College London London UK Kirchhoff-Institut für Physik Ruprecht-Karls-Universität Heidelberg Heidelberg Germany LAPP Université Savoie Mont Blanc CNRS/IN2P3 Annecy France AGH University of Krakow Faculty of Physics and Applied Computer Science Krakow Poland Department of Physics Brandeis University Waltham USA School of Physics and Astronomy University of Manchester Manchester UK Department of Physics Northern Illinois University DeKalb USA Department of Physics Istanbul University Istanbul Türkiye Particle Physics Department Rutherford Appleton Laboratory Didcot UK Santa Cruz Institute for Particle Physics University of California Santa Cruz Santa Cruz USA Enrico Fermi Institute University of Chicago Chicago USA Institut de Física d’Altes Energies (IFAE) Barcelona Institute of Science and Technology Barcelona Spain INFN Sezione di Pavia Pavia Italy Dipartimento di Fisica Università di Pavia Pavia Italy Institut für Physik Universität Mainz Mainz Germany Department of Physics Alexandru Ioan Cuza University of

The ratio of branching ratios of the W boson to muons and electrons, $$R^{\,\mu /e}_W={{\mathcal {B}}(W\rightarrow \mu \nu )}$$ / $${{\mathcal {B}}(W\rightarrow e\nu )}$$ , has been measured using $$140\,\text{ fb}^{-1}\,$$ of pp collision data at $$\sqrt{s}=13$$ $$\text {T}\text {e}\hspace{-1.00006pt}\text {V}$$ collected with the ATLAS detector at the LHC, probing the universality of lepton couplings. The ratio is obtained from measurements of the $$t\bar{t}$$ production cross-section in the ee, $$e\mu $$ and $$\mu \mu $$ dilepton final states. To reduce systematic uncertainties, it is normalised by the square root of the corresponding ratio $$R^{\,\mu \mu /ee}_Z$$ for the Z boson measured in inclusive $$Z\rightarrow ee$$ and $$Z\rightarrow \mu \mu $$ events. By using the precise value of $$R^{\,\mu \mu /ee}_Z$$ determined from $$e^+e^-$$ colliders, the ratio $$R^{\,\mu /e}_W$$ is determined to be $$\begin{aligned} R^{\,\mu /e}_W&= 0.9995\pm 0.0022\,\mathrm {(stat)}\,\pm 0.0036\,\mathrm {(syst)}\\ &\quad \pm 0.0014\,\mathrm {(ext)} . \end{aligned}$$ The three uncertainties correspond to data statistics, experimental systematics and the external measurement of $$R^{\,\mu \mu /ee}_Z$$ , giving a total uncertainty of 0.0045, and confirming the Standard Model assumption of lepton flavour universality in W-boson decays at the 0.5% level.

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