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Publikacje z roku: 2022
artykuł w czasopiśmie
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A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery [2022]
Autorzy: Adamczyk Leszek Bołd Tomasz Dąbrowski Władysław Dyndał Mateusz Grabowska-Bołd Iwona Janas Krzysztof W. Koperny Stefan Kremer Jakub Łakomiec Inga K. Maj Klaudia Mindur Bartosz Ogrodnik Agnieszka Przybycień Mariusz
Wydawnictwo: Nature
The standard model of particle physics1–4 describes the known fundamental particles and forces that make up our Universe, with the exception of gravity. One of the central features of the standard model is a field that permeates all of space and interacts with fundamental particles5–9. The quantum excitation of this field, known as the Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the standard model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN10,11. Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons—the carriers of the strong, electromagnetic and weak forces—are studied in detail. Interactions with three third-generation matter particles (bottom (b) and top (t) quarks, and tau leptons (τ)) are well measured and indications of interactions with a second-generation particle (muons, μ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model.
Źródło: https://www.nature.com/articles/s41586-022-04893-w.pdf
DOI: 10.1038/s41586-022-04893-w
Otwarty dostęp: tak
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A search for an unexpected asymmetry in the production of e^+\mu^− and e^−\mu^+ pairs in protonproton collisions recorded by the ATLAS detector at \sqrts = 13 TeV [2022]
Autorzy: Adamczyk Leszek Bołd Tomasz Dąbrowski Władysław Dyndał Mateusz Grabowska-Bołd Iwona Janas Krzysztof W. Koperny Stefan Łakomiec Inga K. Maj Klaudia Mindur Bartosz Ogrodnik Agnieszka Palni Prabhakar Przybycień Mariusz
Wydawnictwo: Physics Letters, B
This search, a type not previously performed at ATLAS, uses a comparison of the production cross sections for e+μ− and e−μ+ pairs to constrain physics processes beyond the Standard Model. It uses 139 fb−1 of proton–proton collision data recorded at √s = 13 TeV at the LHC. Targeting sources of new physics which prefer final states containing e+μ− to e−μ+, the search contains two broad signal regions which are used to provide model-independent constraints on the ratio of cross sections at the 2% level. The search also has two special selections targeting supersymmetric models and leptoquark signatures. Observations using one of these selections are able to exclude, at 95% confidence level, singly produced smuons with masses up to 640 GeV in a model in which the only other light sparticle is a neutralino when the Rparity-violating coupling λ 231 is close to unity. Observations using the other selection exclude scalar leptoquarks with masses below 1880 GeV when geu 1R = g μc 1R = 1, at 95% confidence level. The limit on the coupling reduces to geu 1R = g μc 1R = 0.46 for a mass of 1420 GeV.
DOI: 10.1016/j.physletb.2022.137106
Otwarty dostęp: tak
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Analysis of neutral B-meson decays into two muons [2022]
Autorzy: Dendek Adam, Firlej Mirosław, Fiutowski Tomasz, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Kucewicz Wojciech, Madejczyk-Dziedzic Olga, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: Physical Review Letters
Branching fraction and effective lifetime measurements of the rare decay B0s→μ+μ− and searches for the decays B0→μ+μ− and B0s→μ+μ−γ are reported using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a luminosity of 9 fb−1. The branching fraction B(B0s→μ+μ−)=(3.09+0.46+0.15−0.43−0.11)×10−9 and the effective lifetime τ(B0s→μ+μ−)=2.07±0.29±0.03 ps are measured, where the first uncertainty is statistical and the second systematic. No significant signal for B0→μ+μ− and B0s→μ+μ−γ decays is found and upper limits B(B0→μ+μ−)<2.6×10−10 and B(B0s→μ+μ−γ)<2.0×10−9 at the 95% C.L. are determined, where the latter is limited to the range mμμ>4.9 GeV/c2. The results are in agreement with the standard model expectations.
Źródło: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.128.041801
DOI: 10.1103/PhysRevLett.128.041801
Otwarty dostęp: tak
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Angular analysis of D^0\to\pi^+\pi^−\mu^+\mu^− and D^0\to K^+K^-\mu^+\mu^− decays and search for CP violation [2022]
Autorzy: Bashir Saliha, Dendek Adam, Firlej Mirosław, Fiutowski Tomasz, Hashmi Sabin, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Madejczyk-Dziedzic Olga, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: Physical Review Letters
The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D0?p+p-µ+µ- and D0?K+K-µ+µ- decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9 fb-1. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry. © 2022 CERN.
Źródło: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.128.221801
DOI: 10.1103/PhysRevLett.128.221801
Otwarty dostęp: tak
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ATHENA detector proposal a totally hermetic electron nucleus apparatus proposed for IP6 at the Electron-Ion Collider [2022]
Autorzy: Adamczyk Leszek, Idzik Marek, Piotrzkowski Krzysztof, Przybycień Mariusz
Wydawnictwo: Journal of Instrumentation
ATHENA has been designed as a general purpose detector capable of delivering the full scientific scope of the Electron-Ion Collider. Careful technology choices provide fine tracking and momentum resolution, high performance electromagnetic and hadronic calorimetry, hadron identification over a wide kinematic range, and near-complete hermeticity. This article describes the detector design and its expected performance in the most relevant physics channels. It includes an evaluation of detector technology choices, the technical challenges to realizing the detector and the R&D required to meet those challenges.
Źródło: https://iopscience.iop.org/article/10.1088/1748-0221/17/10/P10019/pdf
DOI: 10.1088/1748-0221/17/10/P10019
Otwarty dostęp: tak
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AtlFast3: the next generation of fast simulation in ATLAS [2022]
Autorzy: Adamczyk Leszek Bołd Tomasz Dąbrowski Władysław Dyndał Mateusz Grabowska-Bołd Iwona Janas Krzysztof W. Koperny Stefan Łakomiec Inga K. Maj Klaudia Mindur Bartosz Ogrodnik Agnieszka Palni Prabhakar Przybycień Mariusz
Wydawnictwo: Computing and Software for Big Science
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 a new ability to model substructure within jets, AtlFast3 is designed to be used to simulate large numbers of events for a wide range of physics processes.
Źródło: https://link.springer.com/content/pdf/10.1007/s41781-021-00079-7.pdf
DOI: 10.1007/s41781-021-00079-7
Otwarty dostęp: tak
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Centrality determination in heavy-ion collisions with the LHCb detector [2022]
Autorzy: Dendek Adam, Firlej Mirosław, Fiutowski Tomasz, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Kucewicz Wojciech, Madejczyk-Dziedzic Olga, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: Journal of Instrumentation
The centrality of heavy-ion collisions is directly related to the created medium in these interactions. A procedure to determine the centrality of collisions with the LHCb detector is implemented for lead-lead collisions at √sNN = 5 TeV and lead-neon fixed-target collisions at √sNN = 69 GeV. The energy deposits in the electromagnetic calorimeter are used to determine and define the centrality classes. The correspondence between the number of participants and the centrality for the lead-lead collisions is in good agreement with the correspondence found in other experiments, and the centrality measurements for the lead-neon collisions presented here are performed for the first time in fixed-target collisions at the LHC.
Źródło: https://iopscience.iop.org/article/10.1088/1748-0221/17/05/P05009/pdf
DOI: 10.1088/1748-0221/17/05/P05009
Otwarty dostęp: tak
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Constraints on the CKM angle \gamma from B^\pm \to Dh^\pm decays using D \to h^\pmh’^\pm\pi^0 final states [2022]
Autorzy: Bashir Saliha, Dendek Adam, Firlej Mirosław, Fiutowski Tomasz, Hashmi Sabin, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Madejczyk-Dziedzic Olga, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: The Journal of High Energy Physics
A data sample collected with the LHCb detector corresponding to an integrated luminosity of 9 fb−1 is used to measure eleven CP violation observables in B±→ Dh± decays, where h is either a kaon or a pion. The neutral D meson decay is reconstructed in the three-body final states: K±π∓π0; π+π−π0; K+K−π0 and the suppressed π±K∓π0 combination. The mode where a large CP asymmetry is expected, B±→ [π±K∓π0]DK±, is observed with a significance greater than seven standard deviations. The ratio of the partial width of this mode relative to that of the favoured mode, B±→ [K±π∓π0]DK±, is RADS(K) = (1.27 ± 0.16 ± 0.02) × 10−2. Evidence for a large CP asymmetry is also seen: AADS(K) = −0.38 ± 0.12 ± 0.02. Constraints on the CKM angle γ are calculated from the eleven reported observables.
Źródło: https://link.springer.com/content/pdf/10.1007/JHEP07(2022)099.pdf
Otwarty dostęp: tak
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Evidence for a new structure in the J/\psi p and J/\psi \bar p systems in B^0s \to J/\psi p \bar p decays [2022]
Autorzy: Bashir Saliha, Dendek Adam, Firlej Mirosław, Fiutowski Tomasz, Hashmi Sabin, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Kucewicz Wojciech, Madejczyk-Dziedzic Olga, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: Physical Review Letters
An amplitude analysis of flavor-untagged B0s→J/ψp¯p decays is performed using a sample of 797±31 decays reconstructed with the LHCb detector. The data, collected in proton-proton collisions between 2011 and 2018, correspond to an integrated luminosity of 9 fb−1. Evidence for a new structure in the J/ψp and J/ψ¯p systems with a mass of 4337+7−4 +2−2 MeV and a width of 29+26−12 +14−14 MeV is found, where the first uncertainty is statistical and the second systematic, with a significance in the range of 3.1 to 3.7σ, depending on the assigned JP hypothesis.
Źródło: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.128.062001
DOI: 10.1103/PhysRevLett.128.062001
Otwarty dostęp: tak
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First measurement of the Z \to \mu^+ \mu^− angular coefficients in the forward region of pp collisions at \sqrts= 13 TeV [2022]
Autorzy: Firlej Mirosław, Fiutowski Tomasz, Idzik Marek, Kopciewicz Paweł, Krupa Wojciech, Kucewicz Wojciech, Majewski Maciej W., Moroń Jakub, Obłąkowska-Mucha Agnieszka, Rachwał Bartłomiej, Ryżka Jakub, Szumlak Tomasz, Świentek Krzysztof
Wydawnictwo: Physical Review Letters
The first study of the angular distribution of μ+μ- pairs produced in the forward rapidity region via the Drell-Yan reaction pp→γ∗/Z+X→ℓ+ℓ-+X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1 fb-1. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the Z-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton. © 2022 CERN.
Źródło: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.129.091801
DOI: 10.1103/PhysRevLett.129.091801
Otwarty dostęp: tak
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Investigation of the light output of 3D-printed plastic scintillators for dosimetry applications [2022]
Autorzy: Fiutowski Tomasz, Górska Wioleta, Hajduga Jakub, Jurgielewicz Paweł, Kalecińska Kamila, Kopeć Maciej, Koperny Stefan, Mindur Bartosz, Moroń Jakub, Szumlak Tomasz
Wydawnictwo: Radiation Measurements
Three-dimensional (3D) printing, specifically digital light processing (DLP) technique, can be used to manufacture plastic scintillators of any shape. The purpose of this study was to determine the light output of DLP 3D-printed scintillators for dosimetry applications. Two types of plastic scintillators with dimensions 10 mm × 10 mm × 10 mm were fabricated using DLP 3D-printing at Hanyang University, South Korea. The light output of these DLP 3D-printed samples was measured and compared to that of a commercial plastic scintillator of the same dimensions, RP-408, produced by casting. The 3D-printed scintillators emitting violet and blue light had a lower relative light output by 49% and 43%, respectively, compared to the RP-408 reference scintillator. We also investigated three types of scintillator surface finishing methods: the original surface made by the 3D printer, a sanded surface, and a polished surface. Furthermore, three wrapping configurations were tested: bare scintillator, diffuse-type polytetrafluoroethylene tape, and specular-type enhanced specular reflector foil. Both reflector types, diffuse and specular, reflected blue light with comparable efficiency. Additionally, emission and transmission spectra of the samples were measured. Emission maxima were located at 430 nm for RP-408, and 438 and 475 nm for two 3D-printed samples. Transmittance at the wavelength of maximum emission was equal to 89% for RP-408, and 73% and 66% for the two DLP-printed samples. Although the light output of the 3D-printed scintillators was about 50% lower than that of the commercial plastic scintillator, due to characteristics of 3D-printed plastic scintillators, i.e. fast, low-cost production, and easy customization of the printed shape, they are promising as an active part of dosimeters for use in high intensity gamma radiation fields produced by medical linear accelerators with acceptable signal-to-noise ratio level.
DOI: 10.1016/j.radmeas.2022.106864
Otwarty dostęp: tak
