https://hdl.handle.net/20.500.14178/909 2026-04-10T21:05:11Z 2026-04-10T21:05:11Z Kout, Jan Krajňák, Tomáš Salvetr, Pavel Podany, Pavel Brazda, Michal Preisler, Dalibor Janeček, Miloš Harcuba, Petr Stráský, Josef Dzugan, Jan https://hdl.handle.net/20.500.14178/3721 2026-03-31T01:00:14Z 2025-01-01T00:00:00Z

Crack-Mitigating Strategy in Directed Energy Deposition of Refractory Complex Concentrated CrNbTiZr Alloy Kout, Jan; Krajňák, Tomáš; Salvetr, Pavel; Podany, Pavel; Brazda, Michal; Preisler, Dalibor; Janeček, Miloš; Harcuba, Petr; Stráský, Josef; Dzugan, Jan The conventional manufacturing of refractory complex concentrated alloys (RCCAs) for high-temperature applications is complicated, particularly when material costs and high melting points of the materials processed are considered. Additive manufacturing (AM) could provide an effective alternative. However, the extreme temperatures involved represent significant challenges for manufacturing defect-free alloys using this approach. To address this issue, we investigated the preparation of a CrNbTiZr quaternary complex concentrated alloy from an equimolar blend of elemental powders using commercially available powder-blown L-DED technology. Initially, the alloys exhibited some defects owing to the internal stress caused by the temperature gradients. This was subsequently resolved by optimizing the deposition strategy. SEM, XRD and EDS were used to analyze the alloy in the as-deposited condition, revealing a BCC phase and a secondary Laves phase. Furthermore, Vickers hardness testing demonstrated a correlation between the hardness and the volume fraction of the Laves phase. Finally, successfully performed compression tests confirmed that the prepared material exhibits high-temperature strength and therefore is promising for high-temperature application under extreme conditions.

2025-01-01T00:00:00Z Aad, G. Aakvaag, E. Abbott, B. Abdelhameed, S. Abeling, K. Abicht, N. J. Abidi, S. H. Aboulhorma, A. Abramowicz, H. Abreu, H. Baroň, Petr Berta, Peter Biroš, Marek Chauhan, Chainika Davídek, Tomáš Divíšek, Martin Dolejší, Jiří Doležal, Zdeněk Faltová, Jana Federič, Pavol Haviernik, Matej Hidić, Nihad Huang, Yicong Jankových, Samuel Kodyš, Peter Leitner, Rupert Karkošová Martinovicová, Gabriela Matoušek, Jan Ogrodnik, Agnieszka Ewa Pauwels, Franciszek Jerzy Monique Petrů, Tadeáš Pleskot, Vojtěch Poláček, Stanislav Řezníček, Pavel Rybář, Martin Scheirich, Daniel Spousta, Martin Sýkora, Martin Sýkora, Tomáš Tas, Petr Timoshyn, Denys Todorova, Šárka Váňa, Pavel Vavřička, Radek Vorobel, Vít https://hdl.handle.net/20.500.14178/3709 2026-03-24T02:00:16Z 2025-01-01T00:00:00Z

Search for squarks and gluinos in pp collisions at √s = 13 TeV and 13.6 TeV in events with τ -leptons, jets and missing transverse momentum using the ATLAS detector Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Baroň, Petr; Berta, Peter; Biroš, Marek; Chauhan, Chainika; Davídek, Tomáš; Divíšek, Martin; Dolejší, Jiří; Doležal, Zdeněk; Faltová, Jana; Federič, Pavol; Haviernik, Matej; Hidić, Nihad; Huang, Yicong; Jankových, Samuel; Kodyš, Peter; Leitner, Rupert; Karkošová Martinovicová, Gabriela; Matoušek, Jan; Ogrodnik, Agnieszka Ewa; Pauwels, Franciszek Jerzy Monique; Petrů, Tadeáš; Pleskot, Vojtěch; Poláček, Stanislav; Řezníček, Pavel; Rybář, Martin; Scheirich, Daniel; Spousta, Martin; Sýkora, Martin; Sýkora, Tomáš; Tas, Petr; Timoshyn, Denys; Todorova, Šárka; Váňa, Pavel; Vavřička, Radek; Vorobel, Vít A search for R-parity-conserving supersymmetry in events with large missing transverse momentum, jetsand at least one hadronically decaying τ -lepton is presented.Both gluino and squark pair production are considered,with the cascade decay of each gluino or squark producingeither a τ -slepton or a τ -sneutrino. Three channels areexamined, requiring either exactly one hadronically decayingτ -lepton and no other leptons, exactly one hadronicallydecaying τ -lepton and at least one other lepton, or two ormore hadronically decaying τ -leptons. Analyses in the threechannels are optimised independently and combined statistically.Two separate analysis strategies, either a cut-and-countor machine-learning approach, are used. The search uses140 fb-1 and 51.8 fb-1 of pp collision data recorded by theATLAS detector at the Large Hadron Collider during 2015-2018 at SQUARE ROOTs = 13 TeV and 2022-2023 at SQUARE ROOTs = 13.6 TeV,respectively. Gluino masses below 2.25 TeV and squark masses up to 1.7 TeV are excluded

2025-01-01T00:00:00Z Aad, G. Aakvaag, E. Abbott, B. Abdelhameed, S. Abeling, K. Abicht, N. J. Abidi, S. H. Aboulhorma, A. Abramowicz, H. Abreu, H. Baroň, Petr Berta, Peter Biroš, Marek Chauhan, Chainika Davídek, Tomáš Divíšek, Martin Doležal, Zdeněk Faltová, Jana Federič, Pavol Haviernik, Matej Hidić, Nihad Huang, Yicong Jankových, Samuel Kodyš, Peter Leitner, Rupert Karkošová Martinovicová, Gabriela Matoušek, Jan Mlynáriková, Michaela Pauwels, Franciszek Jerzy Monique Petrů, Tadeáš Pleskot, Vojtěch Poláček, Stanislav Řezníček, Pavel Rybář, Martin Scheirich, Daniel Spousta, Martin Sýkora, Martin Sýkora, Tomáš Tas, Petr Timoshyn, Denys Todorova, Šárka Váňa, Pavel Vavřička, Radek https://hdl.handle.net/20.500.14178/3708 2026-03-24T02:00:25Z 2025-01-01T00:00:00Z

Measurements and interpretations of W+-Z production cross-sections in pp collisions at SQUARE ROOTs = 13 TeV with the ATLAS detector Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Baroň, Petr; Berta, Peter; Biroš, Marek; Chauhan, Chainika; Davídek, Tomáš; Divíšek, Martin; Doležal, Zdeněk; Faltová, Jana; Federič, Pavol; Haviernik, Matej; Hidić, Nihad; Huang, Yicong; Jankových, Samuel; Kodyš, Peter; Leitner, Rupert; Karkošová Martinovicová, Gabriela; Matoušek, Jan; Mlynáriková, Michaela; Pauwels, Franciszek Jerzy Monique; Petrů, Tadeáš; Pleskot, Vojtěch; Poláček, Stanislav; Řezníček, Pavel; Rybář, Martin; Scheirich, Daniel; Spousta, Martin; Sýkora, Martin; Sýkora, Tomáš; Tas, Petr; Timoshyn, Denys; Todorova, Šárka; Váňa, Pavel; Vavřička, Radek Measurements of integrated and differential cross-sections for W+-Z production in proton-proton collisions are presented. The data collected by the ATLAS detector at theLarge Hadron Collider from 2015 to 2018 at a centre-of-mass energy of SQUARE ROOTs = 13TeV areused, corresponding to an integrated luminosity of 140 fb-1. The W+-Z candidate events arereconstructed using leptonic decay modes of the gauge bosons into electrons or muons. Theintegrated cross-section per lepton flavour for the production of W+-Z is measured in thedetector fiducial region with a relative precision of 4%. The measured value is compared withthe Standard Model prediction at a precision of up to next-to-next-to-leading-order in QCDand next-to-leading-order in electroweak. Cross-sections for W+Z and W-Z production andtheir ratio are presented. The W+-Z production is also measured differentially as functions ofvarious kinematic variables, including new observables sensitive to CP-violation effects. Allmeasurements are compared with state-of-the-art Standard Model predictions from fixedordercalculations or Monte Carlo generators based on next-to-leading-order matrix elementsinterfaced with parton showers. An effective field theory interpretation of the measurements isperformed, considering both CP-conserving and CP-violating dimension-6 operators modifyingthe W+-Z production. In the absence of observed deviations from the Standard Model, limitson CP-conserving Wilson coefficients are extracted using the transverse mass of the W+-Zsystem. For CP-violating coefficients a machine learning approach is used to construct an observable with enhanced sensitivity to CP-violation effects.

2025-01-01T00:00:00Z Aad, G. Aakvaag, E. Abbott, B. Abdelhameed, S. Abeling, K. Abicht, N. J. Abidi, S. H. Aboulhorma, A. Abramowicz, H. Abreu, H. Berta, Peter Biroš, Marek Chauhan, Chainika Davídek, Tomáš Divíšek, Martin Doležal, Zdeněk Faltová, Jana Federič, Pavol Haviernik, Matej Hidić, Nihad Huang, Yicong Jankových, Samuel Kodyš, Peter Leitner, Rupert Karkošová Martinovicová, Gabriela Matoušek, Jan Ogrodnik, Agnieszka Ewa Pauwels, Franciszek Jerzy Monique Petrů, Tadeáš Pleskot, Vojtěch Poláček, Stanislav Řezníček, Pavel Rybář, Martin Scheirich, Daniel Spousta, Martin Sýkora, Martin Sýkora, Tomáš Tas, Petr Timoshyn, Denys Todorova, Šárka Váňa, Pavel Vavřička, Radek Baroň, Petr https://hdl.handle.net/20.500.14178/3707 2026-03-24T02:00:56Z 2025-01-01T00:00:00Z

Estimation of backgrounds from jets misidentified as τ-leptons using the Universal Fake Factor method with the ATLAS detector Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Berta, Peter; Biroš, Marek; Chauhan, Chainika; Davídek, Tomáš; Divíšek, Martin; Doležal, Zdeněk; Faltová, Jana; Federič, Pavol; Haviernik, Matej; Hidić, Nihad; Huang, Yicong; Jankových, Samuel; Kodyš, Peter; Leitner, Rupert; Karkošová Martinovicová, Gabriela; Matoušek, Jan; Ogrodnik, Agnieszka Ewa; Pauwels, Franciszek Jerzy Monique; Petrů, Tadeáš; Pleskot, Vojtěch; Poláček, Stanislav; Řezníček, Pavel; Rybář, Martin; Scheirich, Daniel; Spousta, Martin; Sýkora, Martin; Sýkora, Tomáš; Tas, Petr; Timoshyn, Denys; Todorova, Šárka; Váňa, Pavel; Vavřička, Radek; Baroň, Petr Processes with τ -leptons in the final state are important for Standard Model measurements and searchesfor physics beyond the Standard Model. The ATLAS experimentat the Large Hadron Collider observes τ -leptons producedin proton-proton collisions only through their decayproducts. Data analyses involving hadronically decayingτ -leptons face challenges due to backgrounds from jetsmisidentified as τ -leptons that are not modelled reliably byMonte Carlo simulations. Data-driven methods such as thefake-factor method allow such misidentified backgrounds tobe predicted by measuring transfer factors, known as fakefactors, in data from dedicated regions. This paper describesa refined technique for determining the fake factors, the UniversalFake Factor method. It evaluates the fake factors fora signal region by using fake factors from samples enrichedin different sources of jets misidentified as τ -leptons (lightquark,gluon, b-quark, and pile-up jets). Each fake factor iscalculated as a linear combination of fake factors measuredin these different enriched samples. For the full Run 2 dataset, the systematic uncertainty of the calculated fake factors,evaluated using W(μν) enriched event sample, ranges from15 to 35% depending on the τ -lepton's transversemomentum and charged-particle decay multiplicity.

2025-01-01T00:00:00Z