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Author Herrero-Garcia, J.; Patrick, R.; Scaffidi, A.
Title A semi-supervised approach to dark matter searches in direct detection data with machine learning Type Journal Article
Year 2022 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue Pages 039 - 19pp
Keywords
Abstract The dark matter sector remains completely unknown. It is therefore crucial to keep an open mind regarding its nature and possible interactions. Focusing on the case of Weakly Interacting Massive Particles, in this work we make this general philosophy more concrete by applying modern machine learning techniques to dark matter direct detection. We do this by encoding and decoding the graphical representation of background events in the XENONnT experiment with a convolutional variational autoencoder. We describe a methodology that utilizes the `anomaly score' derived from the reconstruction loss of the convolutional variational autoencoder as well as a pre-trained standard convolutional neural network, in a semi-supervised fashion. Indeed, we observe that optimum results are obtained only when both unsupervised and supervised anomaly scores are considered together. A data set that has a higher proportion of anomaly score is deemed anomalous and deserves further investigation. Contrary to classical analyses, in principle all information about the events is used, preventing unnecessary information loss. Lastly, we demonstrate the reach of learning-focused anomaly detection in this context by comparing results with classical inference, observing that, if tuned properly, these techniques have the potential to outperform likelihood-based methods.
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Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5495
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Author Liptak, Z. et al; Marinas, C.
Title Measurements of beam backgrounds in SuperKEKB Phase 2 Type Journal Article
Year 2022 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1040 Issue Pages 167168 - 19pp
Keywords
Abstract The high design luminosity of the SuperKEKB electron–positron collider will result in challenging levels of beam-induced backgrounds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of the Belle II experiment. We report on the first background measurements performed after roll-in of the Belle II detector, a period known as SuperKEKB Phase 2, utilizing both the BEAST II system of dedicated background detectors and the Belle II detector itself. We also report on first revisions to the background simulation made in response to our findings. Backgrounds measured include contributions from synchrotron radiation, beam-gas, Touschek, and injection backgrounds. At the end of Phase 2, single-beam backgrounds originating from the 4 GeV positron Low Energy Ring (LER) agree reasonably well with simulation, while backgrounds from the 7 GeV electron High Energy Ring (HER) are approximately one order of magnitude higher than simulation. We extrapolate these backgrounds forward and conclude it is safe to install the Belle II vertex detector.
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Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5496
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Author Middeldorf-Wygas, M.M.; Oldengott, I.M.; Bödeker, D.; Schwarz, D.J.
Title Cosmic QCD transition for large lepton flavor asymmetries Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 105 Issue Pages 123533 - 10pp
Keywords
Abstract We study the impact of large lepton flavor asymmetries on the cosmic QCD transition. Scenarios of unequal lepton flavor asymmetries are observationally almost unconstrained and therefore open up a whole new parameter space for the cosmic QCD transition. We find that for large asymmetries, the formation of a Bose-Einstein condensate of pions can occur and identify the corresponding parameter space. In the vicinity of the QCD transition scale, we express the pressure in terms of a Taylor expansion with respect to the complete set of chemical potentials. The Taylor coefficients rely on input from lattice QCD calculations from the literature. The domain of applicability of this method is discussed.
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Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5497
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Author NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.
Title Search for a New B-L Z' Gauge Boson with the NA64 Experiment at CERN Type Journal Article
Year 2022 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 129 Issue Pages 161801 - 6pp
Keywords
Abstract A search for a new Z′ gauge boson associated with (un)broken B−L symmetry in the keV–GeV mass range is carried out for the first time using the missing-energy technique in the NA64 experiment at the CERN SPS. From the analysis of the data with 3.22×10^11 electrons on target collected during 2016–2021 runs, no signal events were found. This allows us to derive new constraints on the Z′−e coupling strength, which, for the mass range 0.3≲ mZ′≲ 100  MeV, are more stringent compared to those obtained from the neutrino-electron scattering data.
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Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5499
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Author Garcia Navarro, J.E.; Fernandez-Prieto, L.M.; Villaseñor, A.; Sanz, V.; Ammirati, J.B.; Diaz Suarez, E.A.; Garcia, C.
Title Performance of Deep Learning Pickers in Routine Network Processing Applications Type Journal Article
Year 2022 Publication Seismological Research Letters Abbreviated Journal Seismol. Res. Lett.
Volume 93 Issue Pages 2529-2542
Keywords
Abstract Picking arrival times of P and S phases is a fundamental and time‐consuming task for the routine processing of seismic data acquired by permanent and temporary networks. A large number of automatic pickers have been developed, but to perform well they often require the tuning of multiple parameters to adapt them to each dataset. Despite the great advance in techniques, some problems remain, such as the difficulty to accurately pick S waves and earthquake recordings with a low signal‐to‐noise ratio. Recently, phase pickers based on deep learning (DL) have shown great potential for event identification and arrival‐time picking. However, the general adoption of these methods for the routine processing of monitoring networks has been held back by factors such as the availability of well‐documented software, computational resources, and a gap in knowledge of these methods. In this study, we evaluate recent available DL pickers for earthquake data, comparing the performance of several neural network architectures. We test the selected pickers using three datasets with different characteristics. We found that the analyzed DL pickers (generalized phase detection, PhaseNet, and EQTransformer) perform well in the three tested cases. They are very efficient at ignoring large‐amplitude transient noise and at picking S waves, a task that is often difficult even for experienced analysts. Nevertheless, the performance of the analyzed DL pickers varies widely in terms of sensitivity and false discovery rate, with some pickers missing a significant percentage of true picks and others producing a large number of false positives. There are also variations in run time between DL pickers, with some of them requiring significant resources to process large datasets. In spite of these drawbacks, we show that DL pickers can be used efficiently to process large seismic datasets and obtain results comparable or better than current standard procedures.
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Corporate Author Thesis
Publisher (up) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5500
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Author ATLAS Collaboration
Title A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery Type Journal Article
Year 2022 Publication Nature Abbreviated Journal Nature
Volume 607 Issue 7917 Pages 52-59
Keywords
Abstract The standard model of particle physics(1-4) 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 particles(5-9). 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 (tau)) are well measured and indications of interactions with a second-generation particle (muons, mu) 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.
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Corporate Author Thesis
Publisher (up) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes WOS:000820564200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5521
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Author Fanchiotti, H.; Garcia Canal, C.A.; Mayosky, M.; Veiga, A.; Vento, V.
Title Measuring the Hannay geometric phase Type Journal Article
Year 2022 Publication American Journal of Physics Abbreviated Journal Am. J. Phys.
Volume 90 Issue 6 Pages 430-435
Keywords
Abstract The Hannay geometric phase is the classical analog of the well-known Berry phase. Its most familiar example is the effect of the latitude lambda on the motion of a Foucault pendulum. We describe an electronic network whose behavior is exactly equivalent to that of the pendulum. The circuit can be constructed from off-the-shelf components using two matched transconductance amplifiers that comprise a gyrator to introduce the non-reciprocal behavior needed to mimic the pendulum. One may precisely measure the dependence of the Hannay phase on lambda by circuit simulation and by laboratory measurements on a constructed circuit.
Address [Fanchiotti, H.; Canal, C. A. Garcia] Univ Nacl La Plata, IFLP, CONICET, CC67, RA-1900 La Plata, Argentina
Corporate Author Thesis
Publisher (up) AIP Publishing Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9505 ISBN Medium
Area Expedition Conference
Notes WOS:000804547100009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5276
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Author Aguilar, A.C.; Ferreira, M.N.; Papavassiliou, J.
Title Exploring smoking-gun signals of the Schwinger mechanism in QCD Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 105 Issue 1 Pages 014030 - 26pp
Keywords
Abstract In Quantum Chromodynamics, the Schwinger mechanism endows the gluons with an effective mass through the dynamical formation of massless bound-state poles that are longitudinally coupled. The presence of these poles affects profoundly the infrared properties of the interaction vertices, inducing crucial modifications to their fundamental Ward identities. Within this general framework, we present a detailed derivation of the non-Abelian Ward identity obeyed by the pole-free part of the three-gluon vertex in the softgluon limit, and determine the smoking-gun displacement that the onset of the Schwinger mechanism produces to the standard result. Quite importantly, the quantity that describes this distinctive feature coincides formally with the bound-state wave function that controls the massless pole formation. Consequently, this signal may be computed in two independent ways: by solving an approximate version of the pertinent BetheSalpeter integral equation, or by appropriately combining the elements that enter in the aforementioned Ward identity. For the implementation of both methods we employ two- and three-point correlation functions obtained from recent lattice simulations, and a partial derivative of the ghost-gluon kernel, which is computed from the corresponding Schwinger-Dyson equation. Our analysis reveals an excellent coincidence between the results obtained through either method, providing a highly nontrivial self-consistency check for the entire approach. When compared to the null hypothesis, where the Schwinger mechanism is assumed to be inactive, the statistical significance of the resulting signal is estimated to be 3 standard deviations.
Address [Aguilar, A. C.; Ferreira, M. N.] Univ Campinas UNICAMP, Inst Phys Gleb Wataghin, BR-13083859 Campinas, SP, Brazil
Corporate Author Thesis
Publisher (up) Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000748623100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5091
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Author Briz, J.A.; Borge, M.J.G.; Rubio, B.; Agramunt, J.; Algora, A.; Deo, A.Y.; Estevez Aguado, M.E.; Farrelly, G.; Fraile, L.M.; Gelletly, W.; Maira, A.; Nacher, E.; Perea, A.; Podolyak, Z.; Poves, A.; Sarriguren, P.; Tengblad, O.
Title Clarifying the structure of low-lying states in Br-72 Type Journal Article
Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 105 Issue 1 Pages 014323 - 17pp
Keywords
Abstract The spins and parities of low-lying states in 72Br populated in the beta decay of 72Kr have been studied via conversion electron spectroscopy. The measurements were carried out at ISOLDE using a miniorange spectrometer with Si(Li) and HPGe detectors for electrons and gamma ray detection. Results of the conversion coefficients corresponding to transitions deexciting 12 levels in 72Br are reported. The multipolarities of the transitions are deduced and the spins and parities of the levels involved are discussed. From the multipolarities of the most intense transitions to the ground state, the spin and parity of the 72Br ground state have been definitely established as 1+. The spin of the 101.2-keV isomeric state is determined to be 3-. The level scheme is compared with mean-field and shell-model calculations and oblate deformation for the 72Br ground state is deduced. No E0 transitions have been found in 72Br. E0 transitions in the neighboring isobaric nuclei, 72Se and 72Ge, have also been studied.
Address [Briz, J. A.; Borge, M. J. G.; Maira, A.; Perea, A.; Sarriguren, P.; Tengblad, O.] CSIC, Inst Estruct Mat, Serrano 113 Bis, E-28006 Madrid, Spain
Corporate Author Thesis
Publisher (up) Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000748401900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5092
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Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.
Title Search for Darkonium in e(+) e(-) Collisions Type Journal Article
Year 2022 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 128 Issue 2 Pages 021802 - 7pp
Keywords
Abstract Collider searches for dark sectors, new particles interacting only feebly with ordinary matter, have largely focused on identifying signatures of new mediators, leaving much of dark sector structures unexplored. In particular, the existence of dark matter bound states (darkonia) remains to be investigated. This possibility could arise in a simple model in which a dark photon (A') is light enough to generate an attractive force between dark fermions. We report herein a search for a J(PC) = 1(--) darkonium state, the Upsilon(D), produced in the reaction e(+) e(-) -> gamma Upsilon(D), Upsilon(D) -> A'A'A', where the dark photons subsequently decay into pairs of leptons or pions, using 514 fb(-1) of data collected with the BABAR detector. No significant signal is observed, and we set bounds on the gamma – A' kinetic mixing as a function of the dark sector coupling constant for 0.001 < m(A)' < 3.16 GeV and 0.05 < m(Upsilon D) < 9.5 GeV.
Address [Lees, J. P.; Poireau, V; Tisserand, V] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, CNRS IN2P3, F-74941 Annecy Le Vieux, France
Corporate Author Thesis
Publisher (up) Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000747228900007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5093
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