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Journal articleAad G, Aakvaag E, Abbott B, et al., 2024,
Search for pair production of boosted Higgs bosons via vector-boson fusion in the bb¯bb¯ final state using pp collisions at s=13TeV with the ATLAS detector
, Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, Vol: 858, ISSN: 0370-2693A search for Higgs boson pair production via vector-boson fusion is performed in the Lorentz-boosted regime, where a Higgs boson candidate is reconstructed as a single large-radius jet, using 140 fb<sup>−1</sup> of proton–proton collision data at s=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Only Higgs boson decays into bottom quark pairs are considered. The search is particularly sensitive to the quartic coupling between two vector bosons and two Higgs bosons relative to its Standard Model prediction, κ<inf>2V</inf>. This study constrains κ<inf>2V</inf> to 0.55<κ<inf>2V</inf><1.49 at the 95% confidence level. The value κ<inf>2V</inf>=0 is excluded with a significance of 3.8 standard deviations with other Higgs boson couplings fixed to their Standard Model values. A search for new heavy spin-0 resonances that would mediate Higgs boson pair production via vector-boson fusion is carried out in the mass range of 1–5 TeV for the first time under several model and decay-width assumptions. No significant deviation from the Standard Model hypothesis is observed and exclusion limits at the 95% confidence level are derived.
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Journal articleFilmer EK, Gallagher J, Grant CM, et al., 2024,
Jet radius dependence of dijet momentum balance and suppression in Pb+Pb collisions at 5.02 TeV with the ATLAS detector
, Physical Review C, Vol: 110, ISSN: 2469-9985This paper describes a measurement of the jet radius dependence of the dijet momentum balance between leading back-to-back jets in Formula Presented of Formula Presented collisions collected in 2018 and Formula Presented of Formula Presented collisions collected in 2017 by the ATLAS detector at the LHC. Both datasets were collected at Formula Presented TeV. Jets are reconstructed using the anti-Formula Presented algorithm with jet radius parameters Formula Presented, 0.3, 0.4, 0.5, and 0.6. The dijet momentum balance distributions are constructed for leading jets with transverse momentum Formula Presented from 100 to 562 GeV for Formula Presented, 0.3, and 0.4 jets, and from 158 to 562 GeV for Formula Presented and 0.6 jets. The absolutely normalized dijet momentum balance distributions are constructed to compare measurements of the dijet yields in Formula Presented collisions directly to the dijet cross sections in Formula Presented collisions. For all jet radii considered here, there is a suppression of more balanced dijets in Formula Presented collisions compared with Formula Presented collisions, while for more imbalanced dijets there is an enhancement. There is a jet radius dependence to the dijet yields, being stronger for more imbalanced dijets than for more balanced dijets. Additionally, jet pair nuclear modification factors are measured. The subleading jet yields are found to be more suppressed than leading jet yields in dijets. A jet radius dependence of the pair nuclear modification factors is observed, with the suppression decreasing with increasing jet radius. These measurements provide new constraints on jet quenching scenarios in the quark-gluon plasma.
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Journal articleFilmer EK, Gallagher J, Grant CM, et al., 2024,
Search for Formula Presented-parity violating supersymmetric decays of the top squark to a Formula Presented-jet and a lepton in Formula Presented Formula Presented collisions with the ATLAS detector
, Physical Review D, Vol: 110, ISSN: 2470-0010A search is presented for direct pair production of the stop, the supersymmetric partner of the top quark, in a decay through an Formula Presented-parity violating coupling to a charged lepton and a Formula Presented-quark. The dataset corresponds to an integrated luminosity of Formula Presented of proton-proton collisions at a center-of-mass energy of Formula Presented collected between 2015 and 2018 by the ATLAS detector at the LHC. The final state has two charged leptons (electrons or muons) and two Formula Presented-jets. The results of the search are interpreted in the context of a Minimal Supersymmetric Standard Model with an additional Formula Presented gauge symmetry that is spontaneously broken. No significant excess is observed over the Standard Model background, and exclusion limits on stop pair production are set at 95% confidence level. The corresponding lower limits on the stop mass for 100% branching ratios to a Formula Presented-quark and an electron, muon, or tau-lepton are 1.9 TeV, 1.8 TeV and 800 GeV, respectively, extending the reach of previous LHC searches.
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
Measurement of the differential cross section for neutral pion production in charged-current muon neutrino interactions on argon with the MicroBooNE detector
, Physical Review D, Vol: 110, ISSN: 2470-0010We present a measurement of neutral pion production in charged-current interactions using data recorded with the MicroBooNE detector exposed to Fermilab's booster neutrino beam. The signal comprises one muon, one neutral pion, any number of nucleons, and no charged pions. Studying neutral pion production in the MicroBooNE detector provides an opportunity to better understand neutrino-argon interactions, and is crucial for future accelerator-based neutrino oscillation experiments. Using a dataset corresponding to 6.86×1020 protons on target, we present single-differential cross sections in muon and neutral pion momenta, scattering angles with respect to the beam for the outgoing muon and neutral pion, as well as the opening angle between the muon and neutral pion. Data extracted cross sections are compared to generator predictions. We report good agreement between the data and the models for scattering angles, except for an over-prediction by generators at muon forward angles. Similarly, the agreement between data and the models as a function of momentum is good, except for an underprediction by generators in the medium momentum ranges, 200-400 MeV for muons and 100-200 MeV for pions.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Performance of the CMS high-level trigger during LHC Run 2
, Journal of Instrumentation, Vol: 19, ISSN: 1748-0221The CERN LHC provided proton and heavy ion collisions during its Run 2 operation period from 2015 to 2018. Proton-proton collisions reached a peak instantaneous luminosity of 2.1× 1034 cm-2s-1, twice the initial design value, at √(s)=13 TeV. The CMS experiment records a subset of the collisions for further processing as part of its online selection of data for physics analyses, using a two-level trigger system: the Level-1 trigger, implemented in custom-designed electronics, and the high-level trigger, a streamlined version of the offline reconstruction software running on a large computer farm. This paper presents the performance of the CMS high-level trigger system during LHC Run 2 for physics objects, such as leptons, jets, and missing transverse momentum, which meet the broad needs of the CMS physics program and the challenge of the evolving LHC and detector conditions. Sophisticated algorithms that were originally used in offline reconstruction were deployed online. Highlights include a machine-learning b tagging algorithm and a reconstruction algorithm for tau leptons that decay hadronically.
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Journal articleAalbers J, Akerib DS, Al Musalhi AK, et al., 2024,
The data acquisition system of the LZ dark matter detector: FADR
, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol: 1068, ISSN: 0168-9002- Cite
- Citations: 1
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Journal articleAnfimov N, Branca A, Bürgi J, et al., 2024,
First demonstration of a combined light and charge pixel readout on the anode plane of a LArTPC
, Journal of Instrumentation, Vol: 19, ISSN: 1748-0221The novel SoLAr concept aims to extend sensitivities of liquid-argon neutrino detectors down to the MeV scale for next-generation detectors. SoLAr plans to accomplish this with a liquid-argon time projection chamber that employs an anode plane with dual charge and light readout, which enables precision matching of light and charge signals for data acquisition and reconstruction purposes. We present the results of a first demonstration of the SoLAr detector concept with a small-scale prototype detector integrating a pixel-based charge readout and silicon photomultipliers on a shared printed circuit board. We discuss the design of the prototype, and its operation and performance, highlighting the capability of such a detector design.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Measurement of the polarizations of prompt and non-prompt J/ψ and ψ(2S) mesons produced in pp collisions at √𝑠 = 13TeV
, Physics Letters B: Nuclear Physics and Particle Physics, Vol: 858, ISSN: 0370-2693The polarizations of prompt and non-prompt J∕ψ and ψ(2S) mesons are measured in proton-proton collisionsat √𝑠 = 13TeV, using data samples collected by the CMS experiment in 2017 and 2018, corresponding to atotal integrated luminosity of 103.3 fb−1. Based on the analysis of the dimuon decay angular distributions inthe helicity frame, the polar anisotropy, 𝜆𝜗, is measured as a function of the transverse momentum, 𝑝T, of thecharmonium states, in the 25–120 and 20–100 GeV ranges for the J∕ψ and ψ(2S), respectively. The non-promptpolarizations agree with predictions based on the hypothesis that, for 𝑝T ≳ 25GeV, the non-prompt J∕ψ and ψ(2S)are predominantly produced in two-body B meson decays. The prompt results clearly exclude strong transversepolarizations, even for 𝑝T exceeding 30 times the J∕ψ mass, where 𝜆𝜗 tends to an asymptotic value around 0.3.Taken together with previous measurements, by CMS and LHCb at √𝑠 = 7TeV, the prompt polarizations show asignificant variation with 𝑝T, at low 𝑝T.
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Journal articleAamir M, Adamov G, Adams T, et al., 2024,
Using graph neural networks to reconstruct charged pion showers in the CMS High Granularity Calorimeter
, JOURNAL OF INSTRUMENTATION, Vol: 19 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Measurement of the B<sub>s</sub><SUP>0</SUP> → J/ψK<sub>S</sub><SUP>0</SUP> effective lifetime from proton-proton collisions at √<i>s</i>=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleAad G, Abbott B, Abeling K, et al., 2024,
Precise measurements of <i>W</i>- and <i>Z</i>-boson transverse momentum spectra with the ATLAS detector using <i>pp</i> collisions at √<i>s</i>=5.02 TeV and 13 TeV
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044- Cite
- Citations: 5
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Measurement of differential ZZ plus jets production cross sections in pp collisions at √<i>s</i>=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS -
Conference paperKitagawa H, Tada T, Abe K, et al., 2024,
Measurements of the charge ratio and polarization of cosmic-ray muons with the Super-Kamiokande detector
, Publisher: AMER PHYSICAL SOC, ISSN: 2470-0010 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Search for the lepton-flavor violating decay <i>B<sub>s</sub></i><SUP>0</SUP> → φμ<SUP>±</SUP>τ<SUP>∓</SUP>
, PHYSICAL REVIEW D, Vol: 110, ISSN: 2470-0010 -
Journal articleAad G, Aakvaag E, Abbott B, et al., 2024,
Search for Light Long-Lived Particles in pp Collisions at sqrt[s]=13 TeV Using Displaced Vertices in the ATLAS Inner Detector.
, Phys Rev Lett, Vol: 133A search for long-lived particles (LLPs) using 140 fb^{-1} of pp collision data with sqrt[s]=13 TeV recorded by the ATLAS experiment at the LHC is presented. The search targets LLPs with masses between 5 and 55 GeV that decay hadronically in the ATLAS inner detector. Benchmark models with LLP pair production from exotic decays of the Higgs boson and models featuring long-lived axionlike particles (ALPs) are considered. No significant excess above the expected background is observed. Upper limits are placed on the branching ratio of the Higgs boson to pairs of LLPs, the cross section for ALPs produced in association with a vector boson, and, for the first time, on the branching ratio of the top quark to an ALP and a u/c quark.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for the 𝑍 boson decay to 𝜏𝜏𝜇𝜇 in proton-proton collisions at √𝑠=13 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007The first search for the 𝑍 boson decay to 𝜏𝜏𝜇𝜇 at the CERN LHC is presented, based on data collected by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. The data are compatible with the predicted background. For the first time, an upper limit at the 95% confidence level of 6.9 times the standard model expectation is placed on the ratio of the 𝑍 →𝜏𝜏𝜇𝜇 to 𝑍 →4𝜇 branching fractions. Limits are also placed on the six flavor-conserving four-lepton effective-field-theory operators involving two muons and two tau leptons, for the first time testing all such operators.
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Journal articleAad G, Abbott B, Abeling K, et al., 2024,
Search for the Exclusive W Boson Hadronic Decays <i>W</i><SUP>±</SUP> → π<SUP>±</SUP>γ, <i>W</i><SUP>±</SUP> → <i>K</i><SUP>±</SUP>γ and <i>W</i><SUP>±</SUP> → ρ<SUP>±</SUP>γ with the ATLAS Detector
, PHYSICAL REVIEW LETTERS, Vol: 133, ISSN: 0031-9007- Cite
- Citations: 1
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Journal articleMori M, Abe K, Hayato Y, et al., 2024,
Development of a Data Overflow Protection System for Super-Kamiokande to Maximize Data from Nearby Supernovae
, PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS, Vol: 2024, ISSN: 2050-3911 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Observation of muonic Dalitz decays of chib mesons and precise spectroscopy of hidden-beauty states
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleAad G, Abbott B, Abeling K, et al., 2024,
Combination and summary of ATLAS dark matter searches interpreted in a 2HDM with a pseudo-scalar mediator using 139 fb<SUP>-1</SUP> of √<i>s</i>=13 TeV <i>pp</i> collision data
, SCIENCE BULLETIN, Vol: 69, Pages: 3005-3035, ISSN: 2095-9273- Cite
- Citations: 2
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Observation of the Λ b 0 → J / ψ Ξ - K + decay
, European Physical Journal C: Particles and Fields, Vol: 84, ISSN: 1124-1861<jats:title>Abstract</jats:title><jats:p>Using proton–proton collision data corresponding to an integrated luminosity of <jats:inline-formula><jats:alternatives><jats:tex-math>$$140\hbox { fb}^{-1}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>140</mml:mn> <mml:mspace/> <mml:msup> <mml:mtext>fb</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> collected by the CMS experiment at <jats:inline-formula><jats:alternatives><jats:tex-math>$$\sqrt{s}= 13\,\text {Te}\hspace{-.08em}\text {V} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> <mml:mspace/> <mml:mtext>Te</mml:mtext> <mml:mspace/> <mml:mtext>V</mml:mtext> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula>, the <jats:inline-formula><jats:alternatives><jats:tex-math>$${{{\Lambda }} _{\text {b}}^{{0}}} \rightarrow {{\text {J}/\uppsi }} {{{\Xi }} ^{{-}}} {{\text {K}} ^{{+}}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math
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Journal articleAbratenko P, Alterkait O, Aldana DA, et al., 2024,
Demonstration of neutron identification in neutrino interactions in the MicroBooNE liquid argon time projection chamber
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044 -
Journal articleAbratenko P, Acciarri R, Adams C, et al., 2024,
Scintillation light in SBND: simulation, reconstruction, and expected performance of the photon detection system
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044 -
Journal articleHori M, 2024,
Status of laser spectroscopy measurements of long-lived antiprotonic and pionic helium atoms at CERN and PSI
, INTERNATIONAL JOURNAL OF MODERN PHYSICS A, Vol: 39, ISSN: 0217-751X -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for Higgs boson pair production with one associated vector boson in proton-proton collisions at √<i>s</i>=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Observation of enhanced long-range elliptic anisotropies inside high-multiplicity jets in pp collisions at √s = 13 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007A search for collective effects inside jets produced in proton-proton collisions is performed via correlation measurements of charged particles using the CMS detector at the CERN LHC. The analysis uses data collected at a center-of-mass energy of √𝑠 =13 TeV, corresponding to an integrated luminosity of 138 fb−1. Jets are reconstructed with the anti-𝑘T algorithm with a distance parameter of 0.8 and are required to have transverse momentum greater than 550 GeV and pseudorapidity |𝜂jet|<1.6. Two-particle correlations among the charged particles within the jets are studied as functions of the particles’ azimuthal angle and pseudorapidity separations (Δ𝜙* and Δ𝜂*) in a jet coordinate basis, where particles’ 𝜂*, 𝜙* are defined relative to the direction of the jet. The correlation functions are studied in classes of in-jet charged-particle multiplicity up to 𝑁jch ≈100. Fourier harmonics are extracted from long-range azimuthal correlation functions to characterize azimuthal anisotropy for |Δ𝜂*| >2. For low-𝑁jch jets, the long-range elliptic anisotropic harmonic, 𝑣*2, is observed to decrease with 𝑁jch. This trend is well described by Monte Carlo event generators. However, a rising trend for 𝑣*2 emerges at 𝑁jch ≳80, hinting at a possible onset of collective behavior, which is not reproduced by the models tested. This observation yields new insights into the dynamics of jet evolution in the vacuum.
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Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Precision measurement of the Ξ<i><sub>b</sub></i><SUP>-</SUP> baryon lifetime
, PHYSICAL REVIEW D, Vol: 110, ISSN: 2470-0010 -
Journal articleAad G, Abbott B, Abeling K, et al., 2024,
Determination of the Relative Sign of the Higgs Boson Couplings to <i>W</i> and <i>Z</i> Bosons Using <i>WH</i> Production via Vector-Boson Fusion with the ATLAS Detector
, PHYSICAL REVIEW LETTERS, Vol: 133, ISSN: 0031-9007 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for production of a single vectorlike quark decaying to 𝑡𝐻 or 𝑡𝑍 in the all-hadronic final state in 𝑝𝑝 collisions at √𝑠 =13 TeV
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 110, ISSN: 1550-2368A search for electroweak production of a single vectorlike T quark in association with a bottom (b) quarkin the all-hadronic decay channel is presented. This search uses proton-proton collision data at ffiffis p ¼13 TeV collected by the CMS experiment at the CERN LHC during 2016–2018, corresponding to anintegrated luminosity of 138 fb−1. The T quark is assumed to have charge 2=3 and decay to a top (t) quarkand a Higgs (H) or Z boson. Hadronic decays of the t quark and the H or Z boson are reconstructed fromthe kinematic properties of jets, including those containing b hadrons. No deviation from the standardmodel prediction is observed in the reconstructed tH and tZ invariant mass distributions. The95% confidence level upper limits on the product of the production cross section and branching fractionof a T quark produced in association with a b quark and decaying via tH or tZ range from 1260 to 68 fb forT quark masses of 600–1200 GeV.
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Journal articleFilmer EK, Grant CM, Jackson P, et al., 2024,
Measurements of jet cross-section ratios in 13 TeV proton-proton collisions with ATLAS
, Physical Review D, Vol: 110, ISSN: 2470-0010Measurements of jet cross-section ratios between inclusive bins of jet multiplicity are performed in Formula Presented of proton-proton collisions with Formula Presented center-of-mass energy, recorded with the ATLAS detector at CERN’s Large Hadron Collider. These ratios are constructed from double-differential cross-section measurements that are made in bins of jet multiplicity and other observables that are sensitive the energy scale and angular distribution of radiation due to the strong interaction in the final state. Additionally, the scalar sum of the two leading jets’ transverse momenta is measured triple differentially, in bins of the third jet’s transverse momentum and of jet multiplicity. These measurements are unfolded to account for acceptance and detector-related effects. The measured distributions are used to construct ratios of the inclusive jet-multiplicity bins, which have been shown to be sensitive to the strong coupling Formula Presented while being less sensitive than other observables to systematic uncertainties and parton distribution functions. The measured distributions are compared with state-of-the-art QCD calculations, including next-to-next-to-leading-order predictions for two- and three-jet events. These predictions are generally found to model the data well and perform best in bins with a modest requirement on the third jet’s transverse momentum. Significant differences between data and Monte Carlo predictions are observed in events with large rapidity gaps and invariant masses of the leading jet pair. Studies leading to reduced jet energy scale uncertainties significantly improve the precision of this work and are documented herein.
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