| 1. |
- Tong, D.M., et al.
(författare)
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Kinematic approach to mixed state geometric phase in nonunitary evolution
- 2004
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 93:8, s. 080405-
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Tidskriftsartikel (refereegranskat)abstract
- A kinematic approach to the geometric phase for mixed quantal states in nonunitary evolution is proposed. This phase is manifestly gauge invariant and can be experimentally tested in interferometry. It leads to well-known results when the evolution is unitary.
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| 2. |
- Aaboud, M, et al.
(författare)
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Search for a Structure in the Bs0 π± Invariant Mass Spectrum with the ATLAS Experiment
- 2018
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 1079-7114 .- 0031-9007. ; 120:20
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Tidskriftsartikel (refereegranskat)abstract
- A search for the narrow structure, X(5568), reported by the D0 Collaboration in the decay sequence X→Bs0π±, Bs0→J/ψφ, is presented. The analysis is based on a data sample recorded with the ATLAS detector at the LHC corresponding to 4.9 fb-1 of pp collisions at 7 TeV and 19.5 fb-1 at 8 TeV. No significant signal was found. Upper limits on the number of signal events, with properties corresponding to those reported by D0, and on the X production rate relative to Bs0 mesons, ρX, were determined at 95% confidence level. The results are N(X)
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| 3. |
- Aaboud, M, et al.
(författare)
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Search for Dark Matter Produced in Association with a Higgs Boson Decaying to b b Using 36 fb-1 of pp Collisions at s =13 TeV with the ATLAS Detector
- 2017
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 119:18
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Tidskriftsartikel (refereegranskat)abstract
- Several extensions of the standard model predict associated production of dark-matter particles with a Higgs boson. Such processes are searched for in final states with missing transverse momentum and a Higgs boson decaying to a bb pair with the ATLAS detector using 36.1 fb-1 of pp collisions at a center-of-mass energy of 13 TeV at the LHC. The observed data are in agreement with the standard model predictions and limits are placed on the associated production of dark-matter particles and a Higgs boson. © 2017 CERN, for the ATLAS Collaboration. Published by the American Physical Society.
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| 4. |
- Aaboud, M, et al.
(författare)
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Search for Resonant and Nonresonant Higgs Boson Pair Production in the b b τ+τ- Decay Channel in pp Collisions at s =13 TeV with the ATLAS Detector
- 2018
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Ingår i: Physical Review Letters. - 1079-7114. ; 121:19
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Tidskriftsartikel (refereegranskat)abstract
- A search for resonant and nonresonant pair production of Higgs bosons in the bbτ+τ- final state is presented. The search uses 36.1 fb-1 of pp collision data with s=13 TeV recorded by the ATLAS experiment at the LHC in 2015 and 2016. Decays of the τ-lepton pairs with at least one τ lepton decaying to final states with hadrons and a neutrino are considered. No significant excess above the expected background is observed in the data. The cross-section times branching ratio for nonresonant Higgs boson pair production is constrained to be less than 30.9 fb, 12.7 times the standard model expectation, at 95% confidence level. The data are also analyzed to probe resonant Higgs boson pair production, constraining a model with an extended Higgs sector based on two doublets and a Randall-Sundrum bulk graviton model. Upper limits are placed on the resonant Higgs boson pair production cross-section times branching ratio, excluding resonances X in the mass range 305 GeV
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| 5. |
- Aad, G, et al.
(författare)
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Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS
- 2020
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Ingår i: Physical Review Letters. - 1079-7114. ; 125
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Tidskriftsartikel (refereegranskat)abstract
- The observation of forward proton scattering in association with lepton pairs (e+e−+p or μ+μ−+p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of √s=13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee+p (μμ+p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced for cross-section measurements in the fiducial detector acceptance, corresponding to σee+p=11.0±2.6(stat)±1.2(syst)±0.3(lumi) and σμμ+p=7.2±1.6(stat)±0.9(syst)±0.2(lumi) fb in the dielectron and dimuon channel, respectively.
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| 6. |
- Aad, G., et al.
(författare)
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Combined Measurement of the Higgs Boson Mass from the H → γγ and H → ZZ* → 4ℓ Decay Channels with the ATLAS Detector Using √s=7, 8, and 13 TeV pp Collision Data
- 2023
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 131:25
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Tidskriftsartikel (refereegranskat)abstract
- A measurement of the mass of the Higgs boson combining the H→ZZ*→4ℓ and H→γγ decay channels is presented. The result is based on 140 fb−1 of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11 GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.
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| 7. |
- Aad, G., et al.
(författare)
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Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ∗→4ℓ Decay Channels with the ATLAS Detector Using √s=7, 8, and 13 TeV pp Collision Data
- 2023
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 131:25
-
Tidskriftsartikel (refereegranskat)abstract
- A measurement of the mass of the Higgs boson combining the H→ZZ∗→4ℓ and H→γγ decay channels is presented. The result is based on 140 fb−1 of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11 GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.
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| 8. |
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| 9. |
- Aad, G, et al.
(författare)
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Dijet Resonance Search with Weak Supervision Using s =13 TeV pp Collisions in the ATLAS Detector
- 2020
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 1079-7114 .- 0031-9007. ; 125:13
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Tidskriftsartikel (refereegranskat)abstract
- This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted topology is dijet events and the features used for machine learning are the masses of the two jets. The resulting analysis is essentially a three-dimensional search A→BC, for mA∼O(TeV), mB,mC∼O(100 GeV) and B, C are reconstructed as large-radius jets, without paying a penalty associated with a large trials factor in the scan of the masses of the two jets. The full run 2 s=13 TeV pp collision dataset of 139 fb-1 recorded by the ATLAS detector at the Large Hadron Collider is used for the search. There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and 8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with mA, mB, and mC. For example, when mA=3 TeV and mBâ200 GeV, a production cross section between 1 and 5 fb is excluded at 95% confidence level, depending on mC. For certain masses, these limits are up to 10 times more sensitive than those obtained by the inclusive dijet search. These results are complementary to the dedicated searches for the case that B and C are standard model bosons. © 2020 CERN.
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| 10. |
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