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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Evidence for tWZ production in proton-proton collisions at s=13 TeV in multilepton final states
, Physics Letters B, Vol: 855, ISSN: 0370-2693The first evidence for the standard model production of a top quark in association with a W boson and a Z bosonis reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via itsdecays to electron or muon pairs. At least one W boson, associated or from top quark decay, decays leptonically,too. The analysed data were recorded by the CMS experiment at the CERN LHC in 2016–2018 in proton-protoncollisions at √𝑠 = 13 TeV, and correspond to an integrated luminosity of 138 fb−1. The measured cross section is354 ± 54(stat) ± 95(syst) fb, and corresponds to a statistical significance of 3.4 standard deviations.
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Journal articleAbe K, Bronner C, Hayato Y, et al., 2024,
Second gadolinium loading to Super-Kamiokande
, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol: 1065, ISSN: 0168-9002 -
Journal articleAmsler C, Breuker H, Bumbar M, et al., 2024,
Injection and capture of antiprotons in a Penning-Malmberg trap using a drift tube accelerator and degrader foil
, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol: 1065, ISSN: 0168-9002 -
Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for Higgs boson pair production in the $$ \textrm{b}\overline{\textrm{b}}{\textrm{W}}^{+}{\textrm{W}}^{-} $$ decay mode in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV
, Journal of High Energy Physics, Vol: 2024<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>A search for Higgs boson pair (HH) production with one Higgs boson decaying to two bottom quarks and the other to two W bosons are presented. The search is done using proton-proton collisions data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup> recorded by the CMS detector at the LHC from 2016 to 2018. The final states considered include at least one leptonically decaying W boson. No evidence for the presence of a signal is observed and corresponding upper limits on the HH production cross section are derived. The limit on the inclusive cross section of the nonresonant HH production, assuming that the distributions of kinematic observables are as expected in the standard model (SM), is observed (expected) to be 14 (18) times the value predicted by the SM, at 95% confidence level. The limits on the cross section are also presented as functions of various Higgs boson coupling modifiers, and anomalous Higgs boson coupling scenarios. In addition, limits are set on the resonant HH production via spin-0 and spin-2 resonances within the mass range 250–900 GeV.</jats:p>
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Journal articleAaij R, Abdelmotteleb ASW, Beteta CA, et al., 2024,
Tracking of charged particles with nanosecond lifetimes at LHCb
, EUROPEAN PHYSICAL JOURNAL C, Vol: 84, ISSN: 1434-6044 -
Journal articleChatterjee S, Dutta A, Das I, 2024,
Effect of structural, magnetic, magnetocaloric, and electrical polarization properties for multiferroic double perovskite Lu<inf>2</inf>CoCrO<inf>6</inf> compound
, Journal of Applied Physics, Vol: 136, ISSN: 0021-8979We synthesized the Lu 2 CoCrO 6 compound, multiferroic member of double perovskite system, by sol-gel method and then investigated the crystal structure, magnetization, magnetocaloric effect (MCE), and electrical polarization study. The analysis of powder x-ray diffraction pattern confirms that the monoclinic crystal structure with P2 1 /n space group is better fitting for the Lu 2 CoCrO 6 compound. Distribution between Co and Cr ions at the B-site is not perfectly ordered. Partial ordering between these B-site cations leads to a certain degree of disorder due to the presence of antisite defects and antiphase boundaries. These anti-site disorders (in the B-site) generate various fascinating magnetic phenomena. Although the temperature dependent inverse susceptibility plot shows predominant antiferromagnetic ground state in this system, simultaneously, a second order magnetic phase transition was observed from the Arrott plot. Moreover, the isothermal magnetization study confirms the coexistence of antiferromagnetic (AFM) and ferromagnetic (FM) phases below the transition temperature. The investigation of the magnetocaloric effect shows that the AFM phase of the system converts into the FM phases above critical field values. However, the breakdown of universal behavior of MCE in the paramagnetic region confirms the coexistence of the AFM phase as a secondary phase within the FM matrix. In addition, at lower temperatures, we observe a clear and well-defined ferroelectric hysteresis loop, suggesting ferroelectricity in the material. From these results, we conclude that Lu 2 CoCrO 6 is a multiferroic material in which the coexisting magnetic and multiferroic phases appear to be correlated and weak magneto-electric coupling was also observed. Furthermore, our experimental results help to encourage basic fundamental as well as applied research on rare-earth and transition metal based double perovskite systems due to their complex exchange interaction and multiferroic beha
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
First Simultaneous Measurement of Differential Muon-Neutrino Charged-Current Cross Sections on Argon for Final States with and without Protons Using MicroBooNE Data.
, Phys Rev Lett, Vol: 133We report the first double-differential neutrino-argon cross section measurement made simultaneously for final states with and without protons for the inclusive muon neutrino charged-current interaction channel. The proton kinematics of this channel are further explored with a differential cross section measurement as a function of the leading proton's kinetic energy that extends across the detection threshold. These measurements use data collected with the MicroBooNE detector from 6.4×10^{20} protons on target from the Fermilab booster neutrino beam with a mean neutrino energy of ∼0.8 GeV. Extensive data-driven model validation utilizing the conditional constraint formalism is employed. This motivates enlarging the uncertainties with an empirical reweighting approach to minimize the possibility of extracting biased cross section results. The extracted nominal flux-averaged cross sections are compared to widely used event generator predictions revealing severe mismodeling of final states without protons for muon neutrino charged-current interactions, possibly from insufficient treatment of final state interactions. These measurements provide a wealth of new information useful for improving event generators which will enhance the sensitivity of precision measurements in neutrino experiments.
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Journal articleRossi R, Andreazza A, Bauce M, et al., 2024,
Crystal channeling investigations at medical synchrotron regimes
, EUROPEAN PHYSICAL JOURNAL PLUS, Vol: 139, ISSN: 2190-5444 -
Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Observation of the ϒ(3S) meson and suppression of ϒ states in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007The production of ϒ(2𝑆) and ϒ(3𝑆) mesons in lead-lead (Pb-Pb) and proton-proton (𝑝𝑝) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The ϒ(3𝑆) meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and 𝑝𝑝 collisions are reported for both the ϒ(2𝑆) and ϒ(3𝑆) mesons, as functions of transverse momentum and Pb-Pb collision centrality. These ratios, when appropriately scaled, are significantly less than unity, indicating a suppression of ϒ yields in Pb-Pb collisions. This suppression increases from peripheral to central Pb-Pb collisions. Furthermore, the suppression is stronger for ϒ(3𝑆) mesons compared to ϒ(2𝑆) mesons, extending the pattern of sequential suppression of quarkonium states in nuclear collisions previously seen for the 𝐽/𝜓, 𝜓(2𝑆), ϒ(1𝑆), and ϒ(2𝑆) mesons.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for narrow trijet resonances in proton-proton collisions at sqrt[s]=13 TeV
, Physical Review Letters, Vol: 133, ISSN: 0031-9007<jats:p>The first search for singly produced narrow resonances decaying to three well-separated hadronic jets is presented. The search uses proton-proton collision data corresponding to an integrated luminosity of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>138</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:msup><a:mrow><a:mi>fb</a:mi></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>1</a:mn></a:mrow></a:msup></a:mrow></a:math> at <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msqrt><c:mi>s</c:mi></c:msqrt><c:mo>=</c:mo><c:mn>13</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mi>TeV</c:mi></c:math>, collected at the CERN LHC. No significant deviations from the background predictions are observed between 1.75 and 9.00 TeV. The results provide the first mass limits on a right-handed boson <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:msub><e:mrow><e:mi>Z</e:mi></e:mrow><e:mrow><e:mi>R</e:mi></e:mrow></e:msub></e:mrow></e:math> decaying to three gluons and on an excited quark decaying via a vector boson to three quarks, as well as updated limits on a Kaluza-Klein gluon decaying via a radion to three gluons.</jats:p> <jats:sec> <jats:title/> <jats:supplementary-material> <jats:permissions> <jats:copyright-statement>© 2024 CERN, for the CMS Collaboration</jats:copyright-statement> <jats:copyright-year>2024</jats:copyright-year>
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Journal articleKashiwagi Y, Abe K, Bronner C, et al., 2024,
Performance of SK-Gd's Upgraded Real-time Supernova Monitoring System
, ASTROPHYSICAL JOURNAL, Vol: 970, ISSN: 0004-637X -
Journal articleBhattacharya A, Habib MR, Ahmed A, et al., 2024,
Spin-valve-like magnetoresistance and anomalous Hall effect in magnetic Weyl metal Mn2 PdSn
, Physical Review B, Vol: 110, ISSN: 2469-9950Realization of noncentrosymmetric magnetic Weyl metals is expected to exhibit anomalous transport properties stemming from the interplay of unusual bulk electronic topology and magnetism. Here, we present spin-valve-like magnetoresistance at room temperature in ferrimagnetic Weyl metal Mn2PdSn that crystallizes in the inverse Heusler structure. Anomalous magnetoresistance displays dominant asymmetric component attributed to domain wall electron scattering, indicative of spin-valve-like behavior. Ab initio calculations confirm the topologically nontrivial nature of the band structure, with Weyl nodes proximate to Fermi energy, providing deeper insights into the observed intrinsic Berry curvature mediated substantial anomalous Hall conductivity. Our results underscore the inverse Heusler compounds as promising platform to realize magnetic Weyl metals/semimetals and leverage emergent transport properties for electronic functionalities.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for dark QCD with emerging jets in proton-proton collisions at s = 13 TeV
, Journal of High Energy Physics, Vol: 2024A search for “emerging jets” produced in proton-proton collisions at a center-of-mass energy of 13 TeV is performed using data collected by the CMS experiment corresponding to an integrated luminosity of 138 fb−1. This search examines a hypothetical dark quantum chromodynamics (QCD) sector that couples to the standard model (SM) through a scalar mediator. The scalar mediator decays into an SM quark and a dark sector quark. As the dark sector quark showers and hadronizes, it produces long-lived dark mesons that subsequently decay into SM particles, resulting in a jet, known as an emerging jet, with multiple displaced vertices. This search looks for pair production of the scalar mediator at the LHC, which yields events with two SM jets and two emerging jets at leading order. The results are interpreted using two dark sector models with different flavor structures, and exclude mediator masses up to 1950 (1950) GeV for an unflavored (flavor-aligned) dark QCD model. The unflavored results surpass a previous search for emerging jets by setting the most stringent mediator mass exclusion limits to date, while the flavor-aligned results provide the first direct mediator mass exclusion limits to date.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Search for a scalar or pseudoscalar dilepton resonance produced in association with a massive vector boson or top quark-antiquark pair in multilepton events at √𝑠 =13 TeV
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 110, ISSN: 1550-2368A search for beyond the standard model spin-0 bosons, 𝜙, that decay into pairs of electrons, muons, or tau leptons is presented. The search targets the associated production of such bosons with a 𝑊 or 𝑍 gauge boson, or a top quark-antiquark pair, and uses events with three or four charged leptons, including hadronically decaying tau leptons. The proton-proton collision data set used in the analysis was collected at the LHC from 2016 to 2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb−1. The observations are consistent with the predictions from standard model processes. Upper limits are placed on the product of cross sections and branching fractions of such new particles over the mass range of 15 to 350 GeV with scalar, pseudoscalar, or Higgs-boson-like couplings, as well as on the product of coupling parameters and branching fractions. Several model-dependent exclusion limits are also presented. For a Higgs-boson-like 𝜙 model, limits are set on the mixing angle of the Higgs boson with the 𝜙 boson. For the associated production of a 𝜙 boson with a top quark-antiquark pair, limits are set on the coupling to top quarks. Finally, limits are set for the first time on a fermiophilic dilaton-like model with scalar couplings and a fermiophilic axion-like model with pseudoscalar couplings.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at √𝑠 =13 TeV
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 110, ISSN: 1550-2368A search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at √𝑠 =13 TeV in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of 103 fb−1 collected in 2016–2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta (𝑝𝛾T >100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (𝑚𝛾𝛾 >350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters |𝜁1| <0.073 TeV−4 and |𝜁2| <0.15 TeV−4, using an effective field theory. Additionally, upper limits are placed on the production of axionlike particles with coupling strength to photons 𝑓−1 that varies from 0.03 TeV−1 to 1 TeV−1 over the mass range from 500 to 2000 GeV.
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Journal articleAcero MA, Acharya B, Adamson P, et al., 2024,
Expanding neutrino oscillation parameter measurements in NOvA using a Bayesian approach
, Physical Review D, Vol: 110, ISSN: 2470-0010NOvA is a long-baseline neutrino oscillation experiment that measures oscillations in charged-current νμ→νμ (disappearance) and νμ→νe (appearance) channels, and their antineutrino counterparts, using neutrinos of energies around 2 GeV over a distance of 810 km. In this work we reanalyze the dataset first examined in our previous paper [Phys. Rev. D 106, 032004 (2022)PRVDAQ2470-001010.1103/PhysRevD.106.032004] using an alternative statistical approach based on Bayesian Markov chain Monte Carlo. We measure oscillation parameters consistent with the previous results. We also extend our inferences to include the first NOvA measurements of the reactor mixing angle θ13, where we find 0.071≤sin22θ13≤0.107, and the Jarlskog invariant, where we observe no significant preference for the CP-conserving value J=0 over values favoring CP violation. We use these results to examine the effects of constraints from short-baseline measurements of θ13 using antineutrinos from nuclear reactors when making NOvA measurements of θ23. Our long-baseline measurement of θ13 is shown to be consistent with the reactor measurements, supporting the general applicability and robustness of the Pontecorvo-Maki-Nakagawa-Sakata framework for neutrino oscillations.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
First observation of the Λb0→ D<sup>+</sup>D<sup>−</sup>Λ decay
, Journal of High Energy Physics, Vol: 2024The Λb0 → D+D−Λ decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.3 fb−1. Using the B0 → D+D−KS0 decay as a reference channel, the product of the relative production cross-section and decay branching fractions is measured to be (Formula presented.) where the first uncertainty is statistical and the second is systematic. The known branching fraction of the reference channel, BB0→D+D−KS0, and the cross-section ratio, σΛb0/σB0, previously measured by LHCb are used to derive the branching fraction of the Λb0→ D+D−Λ decay (Formula presented.) where the third and fourth contributions are due to uncertainties of BB0→D+D−KS0 and σΛb0/σB0, respectively. Inspection of the D+Λ and D+D− invariant-mass distributions suggests a rich presence of intermediate resonances in the decay. The Λb0 → D*+D−Λ decay is also observed for the first time as a partially reconstructed component in the D+D−Λ invariant mass spectrum.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for long-lived heavy neutral leptons decaying in the CMS muon detectors in proton-proton collisions at √𝑠 =13 TeV
, Physical Review C: Nuclear Physics, Vol: 110, ISSN: 0556-2813A search for heavy neutral leptons (HNLs) decaying in the CMS muon system is presented. A data sample is used corresponding to an integrated luminosity of 138 fb−1 of proton-proton collisions at √𝑠 =13 TeV, recorded at the CERN LHC in 2016–2018. Decay products of long-lived HNLs could interact with the shielding materials in the CMS muon system and create hadronic and electromagnetic showers detected in the muon chambers. This distinctive signature provides a unique handle to search for HNLs with masses below 4 GeV and proper decay lengths of the order of meters. The signature is sensitive to HNL couplings to all three generations of leptons. Candidate events are required to contain a prompt electron or muon originating from a vertex on the beam axis and a displaced shower in the muon chambers. No significant deviations from the standard model background expectation are observed. In the electron (muon) channel, the most stringent limits to date are set for HNLs in the mass range of 2.1–3.0 (1.9–3.3) GeV, reaching mixing matrix element squared values as low as 8.6(4.6) ×10−6.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Observation of the Ξ−𝑏 →𝜓(2𝑆)Ξ− Ξ− decay and studies of the Ξ𝑏(5945)0 baryonin proton-proton collisions at √𝑠 =13 TeV
, Physical Review C: Nuclear Physics, Vol: 110, ISSN: 0556-2813The first observation of the decay Ξ−𝑏 →𝜓(2𝑆)Ξ− and measurement of the branching ratio of Ξ−𝑏 →𝜓(2𝑆)Ξ− to Ξ−𝑏 →𝐽/𝜓Ξ− are presented. The 𝐽/𝜓 and 𝜓(2𝑆) mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at √𝑠 =13 TeV in 2016–2018, corresponding to an integrated luminosity of 140 fb−1. The branching fraction ratio is measured to be ℬ(Ξ−𝑏→𝜓(2𝑆)Ξ−)/ℬ(Ξ−𝑏→𝐽/𝜓Ξ−)=0.84+0.21−0.19(stat)±0.10(syst)±0.02(ℬ), where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the Ξ𝑏(5945)0 baryon mass and natural width are also presented, using the Ξ−𝑏𝜋+ final state, where the Ξ−𝑏 baryon is reconstructed through the decays 𝐽/𝜓Ξ−, 𝜓(2𝑆)Ξ−, 𝐽/𝜓Λ𝐾−, and 𝐽/𝜓Σ0𝐾−. Finally, the fraction of Ξ−𝑏 baryons produced from Ξ𝑏(5945)0 decays is determined.
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Journal articleAaij R, Abdelmotteleb ASW, Abellan Beteta C, et al., 2024,
Search for the Bs0→ μ<sup>+</sup>μ<sup>−</sup>γ decay
, Journal of High Energy Physics, Vol: 2024A search for the fully reconstructed Bs0→ μ+μ−γ decay is performed at the LHCb experiment using proton-proton collisions at s = 13 TeV corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is found and upper limits on the branching fraction in intervals of the dimuon mass are set (Formula presented.) at 95% confidence level. Additionally, upper limits are set on the branching fraction in the [2mμ, 1.70] GeV/c2 dimuon mass region excluding the contribution from the intermediate ϕ(1020) meson, and in the region combining all dimuon-mass intervals.
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Journal articleThe CMS Collaboration, 2024,
Extracting the speed of sound in quark–gluon plasma with ultrarelativistic lead–lead collisions at the LHC
, Reports on Progress in Physics, Vol: 87, ISSN: 0034-4885Ultrarelativistic nuclear collisions create a strongly interacting state of hot and dense quark–gluon matter that exhibits a remarkable collective flow behavior with minimal viscous dissipation. To gain deeper insights into its intrinsic nature and fundamental degrees of freedom, we determine the speed of sound in an extended volume of quark–gluon plasma using lead–lead (PbPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data were recorded by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 0.607 nb−1. The measurement is performed by studying the multiplicity dependence of the average transverse momentum of charged particles emitted in head-on PbPb collisions. Our findings reveal that the speed of sound in this matter is nearly half the speed of light, with a squared value of 0.241 ± 0.002 (stat) ± 0.016 (syst) in natural units. The effective medium temperature, estimated using the mean transverse momentum, is 219 ± 8 (syst) MEV. The measured squared speed of sound at this temperature aligns precisely with predictions from lattice quantum chromodynamic (QCD) calculations. This result provides a stringent constraint on the equation of state of the created medium and direct evidence for a deconfined QCD phase being attained in relativistic nuclear collisions.
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
First application of a liquid argon time projection chamber for the search for intranuclear neutron-antineutron transitions and annihilation in <sup>40</sup>Ar using the MicroBooNE detector
, Journal of Instrumentation, Vol: 19We present a novel methodology to search for intranuclear neutron-antineutron transition (n → n̄) followed by n̄-nucleon annihilation within an 40Ar nucleus, using the MicroBooNE liquid argon time projection chamber (LArTPC) detector. A discovery of n → n̄ transition or a new best limit on the lifetime of this process would either constitute physics beyond the Standard Model or greatly constrain theories of baryogenesis, respectively. The approach presented in this paper makes use of deep learning methods to select n → n̄ events based on their unique features and differentiate them from cosmogenic backgrounds. The achieved signal and background efficiencies are (70.22 ± 6.04)% and (0.0020 ± 0.0003)%, respectively. A demonstration of a search is performed with a data set corresponding to an exposure of 3.32 × 1026 neutron-years, and where the background rate is constrained through direct measurement, assuming the presence of a negligible signal. With this approach, no excess of events over the background prediction is observed, setting a demonstrative lower bound on the n → n̄ lifetime in 40Ar of τm ≳ 1.1 × 1026 years, and on the free n → n̄ transition time of τn→n̄ ≳ 2.6 × 105 s, each at the 90% confidence level. This analysis represents a first-ever proof-of-principle demonstration of the ability to search for this rare process in LArTPCs with high efficiency and low background.
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Journal articleAbratenko P, Alterkait O, Andrade Aldana D, et al., 2024,
Inclusive cross section measurements in final states with and without protons for charged-current νμ -Ar scattering in MicroBooNE
, Physical Review D, Vol: 110, ISSN: 2470-0010A detailed understanding of inclusive muon neutrino charged-current interactions on argon is crucial to the study of neutrino oscillations in current and future experiments using liquid argon time projection chambers. To that end, we report a comprehensive set of differential cross section measurements for this channel that simultaneously probe the leptonic and hadronic systems by dividing the channel into final states with and without protons. Measurements of the proton kinematics and proton multiplicity of the final state are also presented. For these measurements, we utilize data collected with the MicroBooNE detector from 6.4×1020 protons on target from the Fermilab booster neutrino beam at a mean neutrino energy of approximately 0.8 GeV. We present in detail the cross section extraction procedure, including the unfolding, and model validation that uses data to model comparisons and the conditional constraint formalism to detect mismodeling that may introduce biases to extracted cross sections that are larger than their uncertainties. The validation exposes insufficiencies in the overall model, motivating the inclusion of an additional data-driven reweighting systematic to ensure the accuracy of the unfolding. The extracted results are compared to a number of event generators and their performance is discussed with a focus on the regions of phase space that indicate the greatest need for modeling improvements.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Test of lepton flavor universality in B<SUP>±</SUP> → K<SUP>±</SUP> μ<SUP>+</SUP>μ<SUP>-</SUP> and B<SUP>±</SUP> → K<SUP>±</SUP> e<SUP>+</SUP> e<SUP>-</SUP> decays in proton-proton collisions at √<i>s</i>=13 TeV
, REPORTS ON PROGRESS IN PHYSICS, Vol: 87, ISSN: 0034-4885 -
Journal articleMwangala BB, Banda K, Chimuka L, et al., 2024,
Analysis of streamflow and rainfall trends and variability over the Lake Kariba Catchment, Upper Zambezi Basin
, HYDROLOGY RESEARCH, Vol: 55, Pages: 683-710, ISSN: 1998-9563 -
Journal articleCMS Collaboration, 2024,
Search for ZZ and ZH production in the bbb¯ b final state using ¯proton-proton collisions at √s = 13 TeV
, European Physical Journal C: Particles and Fields, Vol: 84, ISSN: 1434-6052A search for ZZ and ZH production in the bbb¯ b¯final state is presented, where H is the standard model (SM)Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosityof 133 fb−1 collected at a center-of-mass energy of 13 TeVwith the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating amulti-dimensional background model based on control samples in data. A multiclass multivariate classifier customizedfor the bbb¯ b final state is developed to derive the background ¯model and extract the signal. The data are found to be consistent, within uncertainties, with the SM predictions. Theobserved (expected) upper limits at 95% confidence level arefound to be 3.8 (3.8) and 5.0 (2.9) times the SM predictionfor the ZZ and ZH production cross sections, respectively.
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Journal articleTumasyan A, Adam W, Andrejkovic JW, et al., 2024,
Search for central exclusive production of top quark pairs in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV with tagged protons
, Journal of High Energy Physics, Vol: 2024<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>A search for the central exclusive production of top quark-antiquark pairs (<jats:inline-formula><jats:alternatives><jats:tex-math>$$ \textrm{t}\overline{\textrm{t}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math></jats:alternatives></jats:inline-formula>) is performed for the first time using proton-tagged events in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 29.4 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup>. The <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \textrm{t}\overline{\textrm{t}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math></jats:alternatives></jats:inline-formula> decay products are reconstructed using the central CMS detector, while forward protons are measured in the CMS-TOTEM precision proton spectrometer. An observed (expected) upper bound on the production cross section of 0.59 (1.14) pb is set at 95% confidence level, for collisions of protons with fractional momentum losses between 2 and 20%.</jats:p>
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for long-lived heavy neutrinos in the decays of B mesons produced in proton-proton collisions at √<i>s</i>=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleChatterjee S, Das I, 2024,
Structural, magnetic, magnetocaloric behavior and magneto-transport, electrical polarization study in 3d based bulk and nano-crystalline multiferroic double perovskite Dy2MnCoO6.
, J Phys Condens Matter, Vol: 36In this paper, we report a detailed investigation of the crystal structure, magnetic, magnetocaloric, magneto-transport and electrical polarization properties of a new multiferroic material in the polycrystalline and nanocrystalline form of the Dy2MnCoO6double perovskite. Both compounds crystallized in the monoclinic structure with P21/n space group. The magnetic properties of both systems are mainly dominant ferromagnetic (FM) and weak antiferromagnetic (AFM). The FM/AFM coupling is related by the competing and combining functions of the radius and the magnetic moments of rare earth ions (i.e. 3d-4f exchange interactions). The reduction of the saturation magnetization in the isothermal magnetization curves can be explained by the existence of anti-phase boundaries and local anti-site defects in the system. Moreover, these materials hold reasonable values of magnetocaloric parameters and the absence of hysteresis makes the system a potential candidate for magnetic refrigeration. These compounds revealed two magnetic phase transitions, according to the appearance of two peaks in the temperature dependence of magnetic entropy change curves. The temperature dependent resistivity data for both the systems display semiconductor nature near room temperature and insulating like behavior at low temperature regime. The variable-range hopping conduction mechanism is used to best understand their transport mechanism. In addition, the electrical polarization loop at low temperature confirms the presence of ferroelectricity for both the studied systems. The decreases polarization under an external magnetic field evidence the weak magnetoelectric coupling. The coexistence of FM ordering with insulating behavior and ferroelectricity at low temperature promises new opportunities and improvements in next generation applications for information storage, spintronic, and sensors.
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Journal articleHayrapetyan A, Tumasyan A, Adam W, et al., 2024,
Search for heavy neutral leptons in final states with electrons, muons, and hadronically decaying tau leptons in proton-proton collisions at √s=13 TeV
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
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