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Journal articleHoenig D, Thielemann F, Karpa L, et al., 2024,
Trapping Ion Coulomb Crystals in an Optical Lattice
, PHYSICAL REVIEW LETTERS, Vol: 132, ISSN: 0031-9007 -
Conference paperFujii Y, 2024,
Charged Lepton Flavour Violation: experimental activities
Charged lepton flavour violation processes are powerful probes to investigate new physics beyond the standard model of particle physics. There are several ongoing activities and future projects. All of them are going to achieve the levels of sensitivity which are able to explore many new physics scenarios, corresponding to higher energy scale than that is directly accessible with present particle colliders. This paper introduces the recent and present experimental efforts in this area of searches, especially focusing on MEG, MEG2, Mu3e, Mu2e and COMET.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Determination of short- and long-distance contributions in B<SUP>0</SUP> → K<SUP>*0</SUP>μ<SUP>+</SUP>μ<SUP>-</SUP> decays
, PHYSICAL REVIEW D, Vol: 109, ISSN: 2470-0010 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Amplitude Analysis of the <i>B</i><SUP>0</SUP> - <i>K</i>*<SUP>0</SUP> μ<SUP>+</SUP>μ<SUP>-</SUP> Decay
, PHYSICAL REVIEW LETTERS, Vol: 132, ISSN: 0031-9007 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for dark matter particles in W<SUP>+</SUP>W<SUP>-</SUP> events with transverse momentum imbalance in proton-proton collisions at √<i>s</i>=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Search for <i>CP</i> violation in the phase space of <i>D</i><SUP>0</SUP> → <i>K</i><sub>S</sub><SUP>0</SUP><i>K</i><SUP>±</SUP>π<SUP>∓</SUP> decays with the energy test
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Observation of WWγ production andsearch for Hγ production in proton-proton collisions at √ s=13 TeV
, Physical Review Letters, Vol: 132, ISSN: 0031-9007The observation of 𝑊𝑊𝛾 production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138 fb−1 is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for 𝑊𝑊𝛾 is 5.9±0.8(stat)±0.8(syst)±0.7(modeling) fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
New structures in the J=ψJ=ψ mass spectrum in proton-proton collisions at √ s=13 TeV
, Physical Review Letters, Vol: 132, ISSN: 0031-9007A search is reported for near-threshold structures in the 𝐽/𝜓𝐽/𝜓 invariant mass spectrum produced in proton-proton collisions at √𝑠=13 TeV from data collected by the CMS experiment, corresponding to an integrated luminosity of 135 fb−1. Three structures are found, and a model with quantum interference among these structures provides a good description of the data. A new structure is observed with a local significance above 5 standard deviations at a mass of 6638+43−38(stat)+16−31(syst) MeV. Another structure with even higher significance is found at a mass of 6847+44−28(stat)+48−20(syst) MeV, which is consistent with the 𝑋(6900) resonance reported by the LHCb experiment and confirmed by the ATLAS experiment. Evidence for another new structure, with a local significance of 4.7 standard deviations, is found at a mass of 7134+48−25(stat)+41−15(syst) MeV. Results are also reported for a model without interference, which does not fit the data as well and shows mass shifts up to 150 MeV relative to the model with interference.
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Journal articleYuzu K, Imamura H, Nozaki T, et al., 2024,
Mechanistic Modeling of Amyloid Oligomer and Protofibril Formation in Bovine Insulin
, JOURNAL OF MOLECULAR BIOLOGY, Vol: 436, ISSN: 0022-2836 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Measurement of <i>J</i>/ψ-pair production in <i>pp</i> collisions at √<i>s</i>=13 TeV and study of gluon transverse-momentum dependent PDFs
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Observation of Ξ<sub>b</sub><SUP>0</SUP>→ Ξ<sub>c</sub> <SUP>+</SUP> D<sub>s</sub><SUP>-</SUP> and Ξ<sub>b</sub><SUP>0</SUP> c D- s decays
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044 -
Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Study of azimuthal anisotropy of γ(1S) mesons in pPb collisions at √S<sub>NN</sub>=8.16 TeV
, Physics Letters B: Nuclear Physics and Particle Physics, Vol: 850, ISSN: 0370-2693The azimuthal anisotropy of (Image 1) mesons in high-multiplicity proton-lead collisions is studied using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 8.16 TeV . The (Image 1) mesons are reconstructed using their dimuon decay channel. The anisotropy is characterized by the second Fourier harmonic coefficients, found using a two-particle correlation technique, in which the Image 1 mesons are correlated with charged hadrons. A large pseudorapidity gap is used to suppress short-range correlations. Nonflow contamination from the dijet background is removed using a low-multiplicity subtraction method, and the results are presented as a function of Image 1 transverse momentum. The azimuthal anisotropies are smaller than those found for charmonia in proton-lead collisions at the same collision energy, but are consistent with values found for Image 1 mesons in lead-lead interactions at a nucleon-nucleon center-of-mass energy of 5.02 TeV.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for long-lived heavy neutral leptons with lepton flavour conserving or violating decays to a jet and a charged lepton
, Journal of High Energy Physics, Vol: 2024A search for long-lived heavy neutral leptons (HNLs) is presented, which considers the hadronic final state and coupling scenarios involving all three lepton generations in the 2–20 GeV HNL mass range for the first time. Events comprising two leptons (electrons or muons) and jets are analyzed in a data sample of proton-proton collisions, recorded with the CMS experiment at the CERN LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. A novel jet tagger, based on a deep neural network, has been developed to identify jets from an HNL decay using various features of the jet and its constituent particles. The network output can be used as a powerful discriminating tool to probe a broad range of HNL lifetimes and masses. Contributions from background processes are determined from data. No excess of events in data over the expected background is observed. Upper limits on the HNL production cross section are derived as functions of the HNL mass and the three coupling strengths VℓN to each lepton generation ℓ and presented as exclusion limits in the coupling-mass plane, as lower limits on the HNL lifetime, and on the HNL mass. In this search, the most stringent limit on the coupling strength is obtained for pure muon coupling scenarios; values of |VμN2| > 5 (4) × 10−7 are excluded for Dirac (Majorana) HNLs with a mass of 10 GeV at a confidence level of 95% that correspond to proper decay lengths of 17 (10) mm.
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
Measurement of ambient radon progeny decay rates and energy spectra in liquid argon using the MicroBooNE detector
, Physical Review D, Vol: 109, ISSN: 2470-0010We report measurements of radon progeny in liquid argon within the MicroBooNE time projection chamber (LArTPC). The presence of specific radon daughters in MicroBooNE's 85 metric tons of active liquid argon bulk is probed with newly developed charge-based low-energy reconstruction tools and analysis techniques to detect correlated Bi214-Po214 radioactive decays. Special datasets taken during periods of active radon doping enable new demonstrations of the calorimetric capabilities of single-phase neutrino LArTPCs for β and α particles with electron-equivalent energies ranging from 0.1 to 3.0 MeV. By applying Bi214-Po214 detection algorithms to data recorded over a 46-day period, no statistically significant presence of radioactive Bi214 is detected, and a limit on the activity is placed at <0.35 mBq/kg at the 95% confidence level. This bulk Bi214 radiopurity limit-the first ever reported for a liquid argon detector incorporating liquid-phase purification-is then further discussed in relation to the targeted upper limit of 1 mBq/kg on bulk Rn222 activity for the DUNE neutrino detector.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Measurements of azimuthal anisotropy of nonprompt D⁰ mesons in PbPb collisions at √sNN = 5.02 TeV
, Physics Letters B: Nuclear Physics and Particle Physics, Vol: 850, ISSN: 0370-2693Measurements of the elliptic (𝑣2) and triangular (𝑣3) azimuthal anisotropy coefficients are presented for D0mesons produced in b hadron decays (nonprompt D0 mesons) in lead-lead collisions at √𝑠NN = 5.02 TeV.The results are compared with previously published charm meson anisotropies measured using prompt D0mesons. The data were collected with the CMS detector in 2018 with an integrated luminosity of 0.58 nb−1.Azimuthal anisotropy is sensitive to the interactions of quarks with the hot and dense medium created inheavy ion collisions. Comparing results for prompt and nonprompt D0 mesons can assist in understandingthe mass dependence of these interactions. The nonprompt results show lower magnitudes of 𝑣2 and 𝑣3 andweaker dependences on the meson transverse momentum and collision centrality than those found for promptD0 mesons. The results are in agreement with theoretical predictions that include a mass dependence in theinteractions of quarks with the medium.
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Journal articlePasatembou E, Baynham CFA, Buchmuller O, et al., 2024,
Progress toward ultra-cold Sr for the AION project-A red MOT and an optical-heterodyne diagnostic tool for injection-locked laser diodes
, AVS QUANTUM SCIENCE, Vol: 6 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at √s=13 TeV
, Physics Letters B, Vol: 850, ISSN: 0370-2693A search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quarkpair is produced in association with a jet, via the pp → tH∕A → ttc and pp → tH∕A → ttu processes. Here, H andA represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalizedtwo-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energyof 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb−1. Final stateswith a same-sign lepton pair in association with jets and missing transverse momentum are considered. NewHiggs bosons in the 200–1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targetedin the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. Nosignificant excess above the standard model prediction is observed. Exclusion limits are derived in the context ofthe g2HDM.
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Journal articleQue Z, Fan H, Loo M, et al., 2024,
LL-GNN: Low Latency Graph Neural Networks on FPGAs for High Energy Physics
, ACM TRANSACTIONS ON EMBEDDED COMPUTING SYSTEMS, Vol: 23, ISSN: 1539-9087 -
Journal articleStray B, Ennis O, Hedges S, et al., 2024,
Centralized design and production of the ultra-high vacuum and laser-stabilization systems for the AION ultra-cold strontium laboratories
, AVS Quantum Science, Vol: 6, ISSN: 2639-0213This paper outlines the centralized design and production of the ultra-high-vacuum sidearm and laser-stabilization systems for the AION Ultra-Cold Strontium Laboratories. Commissioning data on the residual gas and steady-state pressures in the sidearm chambers, on magnetic field quality, on laser stabilization, and on the loading rate for the 3D magneto-optical trap are presented. Streamlining the design and production of the sidearm and laser stabilization systems enabled the AION Collaboration to build and equip in parallel five state-of-the-art Ultra-Cold Strontium Laboratories within 24 months by leveraging key expertise in the collaboration. This approach could serve as a model for the development and construction of other cold atom experiments, such as atomic clock experiments and neutral atom quantum computing systems, by establishing dedicated design and production units at national laboratories.
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Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Curvature-bias corrections using a pseudomass method
, JOURNAL OF INSTRUMENTATION, Vol: 19, ISSN: 1748-0221 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Measurement of the CKM angle γ in the B<SUP>0</SUP>→DK <SUP>*0</SUP> channel using self-conjugate D→ K<sub>S</sub><SUP>0</SUP>h<SUP>+</SUP> h<SUP>-</SUP> decays
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044 -
Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Enhanced Production of Λ_{b}^{0} Baryons in High-Multiplicity pp Collisions at sqrt[s]=13 TeV.
, Phys Rev Lett, Vol: 132The production rate of Λ_{b}^{0} baryons relative to B^{0} mesons in pp collisions at a center-of-mass energy sqrt[s]=13 TeV is measured by the LHCb experiment. The ratio of Λ_{b}^{0} to B^{0} production cross sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e^{+}e^{-} collisions, and increases by a factor of ∼2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λ_{b}^{0} to B^{0} cross sections is higher than what is measured in e^{+}e^{-} collisions, but converges with the e^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy b quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with several models and implications for the mechanisms enforcing quark confinement are discussed.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Two-particle Bose-Einstein correlations and their Lévy parameters in PbPb collisions at<i> √sNN</i>=5.02 TeV
, Physical Review C: Nuclear Physics, Vol: 109, ISSN: 0556-2813Two-particle Bose–Einstein momentum correlation functions are studied for charged-hadron pairs in lead-lead collisions at a center-of-mass energy per nucleon pair of √𝑠NN=5.02TeV. The data sample, containing 4.27×109 minimum bias events corresponding to an integrated luminosity of 0.607 nb−1, was collected by the CMS experiment in 2018. The experimental results are discussed in terms of a Lévy-type source distribution. The parameters of this distribution are extracted as functions of particle pair average transverse mass and collision centrality. These parameters include the Lévy index or shape parameter 𝛼, the Lévy scale parameter 𝑅, and the correlation strength parameter 𝜆. The source shape, characterized by 𝛼, is found to be neither Cauchy nor Gaussian, implying the need for a full Lévy analysis. Similarly to what was previously found for systems characterized by Gaussian source radii, a hydrodynamical scaling is observed for the Lévy 𝑅 parameter. The 𝜆 parameter is studied in terms of the core-halo model.
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Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Observation of Cabibbo-Suppressed Two-Body Hadronic Decays and Precision Mass Measurement of the Ω<SUP>0</SUP><sub>c </sub>Baryon
, PHYSICAL REVIEW LETTERS, Vol: 132, ISSN: 0031-9007 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Study of <i>B<sub>c</sub></i><SUP>+</SUP> → χ<i><sub>c</sub></i> π<SUP>+</SUP> decays
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleArmano M, Audley H, Baird J, et al., 2024,
Sensor noise in<i> LISA</i><i> Pathfinder:</i> Laser frequency noise and its coupling to the optical test mass readout
, PHYSICAL REVIEW D, Vol: 109, ISSN: 2470-0010 -
Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
A model-independent measurement of the CKM angle γ in partially reconstructed B<SUP>±</SUP>→D<SUP>∗</SUP>h<SUP>± </SUP>decays with D→K<SUP>0</SUP><sub>S</sub>h<SUP>+</SUP>h<SUP>-</SUP>(h=π,K)
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articlePal K, Das I, 2024,
Exploring the exchange bias of Gd and MnPt: A combined structural and magnetic investigation
, Thin Solid Films, Vol: 790, ISSN: 0040-6090Magnetic manipulation in thin films is essential for modern technology. Extensive studies on exchange bias with antiferromagnetic materials and transition metals exist, but research on rare earth elements is limited. This study investigates the formation of the L10-MnPt phase and a ferromagnetic-like Gd phase on Si/SiO2 thin films. We observed thickness-dependent anisotropic magnetic fields in Gd thin films and thickness-dependent exchange bias in the heterojunctions. These findings enhance our understanding of the magnetic properties of MnPt, Gd and the multilayer heterostructure.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Higher-order moments of the elliptic flow distribution in PbPb collisions at sNN = 5.02 TeV
, The Journal of High Energy Physics, Vol: 2024, ISSN: 1029-8479The hydrodynamic flow-like behavior of charged hadrons in high-energy lead-lead collisions is studied through multiparticle correlations. The elliptic anisotropy values based on different orders of multiparticle cumulants, v2{2k}, are measured up to the tenth order (k = 5) as functions of the collision centrality at a nucleon-nucleon center-of-mass energy of √⁸NN = 5.02 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 0.607 nb−1. A hierarchy is observed between the coefficients, with v2{2} > v2{4} ≳ v2{6} ≳ v2{8} ≳ v2{10}. Based on these results, centrality-dependent moments for the fluctuation-driven event-by-event v2 distribution are determined, including the skewness, kurtosis and, for the first time, superskewness. Assuming a hydrodynamic expansion of the produced medium, these moments directly probe the initial-state geometry in high-energy nucleus-nucleus collisions.
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Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Production of η and<i> η'</i> mesons in<i> pp</i> and pPb collisions
, PHYSICAL REVIEW C, Vol: 109, ISSN: 2469-9985
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