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Author Figueroa, D.G.; Pieroni, M.; Ricciardone, A.; Simakachorn, P.
Title Cosmological Background Interpretation of Pulsar Timing Array Data Type Journal Article
Year 2024 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 132 Issue 17 Pages 171002 - 9pp
Keywords
Abstract We discuss the interpretation of the detected signal by pulsar timing array (PTA) observations as a gravitational wave background of cosmological origin. We combine NANOGrav 15-years and EPTADR2new datasets and confront them against backgrounds from supermassive black hole binaries (SMBHBs), and cosmological signals from inflation, cosmic (super)strings, first-order phase transitions, Gaussian and non-Gaussian large scalar fluctuations, and audible axions. We find that scalar-induced, and to a lesser extent audible axion and cosmic superstring signals, provide a better fit than SMBHBs. These results depend, however, on modeling assumptions, so further data and analysis are needed to reach robust conclusions. Independently of the signal origin, the data strongly constrain the parameter space of cosmological signals, for example, setting an upper bound on primordial non-Gaussianity at PTA scales as jfraj less than or similar to 2.34 at 95% C.L.
Address [Figueroa, Daniel G.; Simakachorn, Peera] CSIC, Inst Fis Corpuscular, Valencia 46980, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language (down) 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:001266039300006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6188
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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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language (down) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5499
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Author ATLAS Collaboration (Aad, G. et al); Amos, K.R.; Aparisi Pozo, J.A.; Bailey, A.J.; Bouchhar, N.; Cabrera Urban, S.; Cantero, J.; Cardillo, F.; Castillo Gimenez, V.; Chitishvili, M.; Costa, M.J.; Didenko,, M.; Escobar, C.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gomez Delegido, A.J.; Gonzalez de la Hoz, S.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Lacasta, C.; Marti-Garcia, S.; Martinez Agullo, P.; Miralles Lopez, M.; Mitsou, V.A.; Monsonis Romero, L.; Moreno Llacer, M.; Munoz Perez, D.; Navarro-Gonzalez, J.; Poveda, J.; Prades Ibañez, A.; Rubio Jimenez, A.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Sanchez Sebastian, V.; Sayago Galvan, I.; Senthilkumar, V.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valiente Moreno, E.; Valls Ferrer, J.A.; Varriale, L.; Villaplana Perez, M.; Vos, M.
Title Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02TeV with the ATLAS Detector Type Journal Article
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 17 Pages 172301 - 22pp
Keywords
Abstract This letter presents a measurement of the nuclear modification factor of large-radius jets in root sNN=5.02 TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72nb^{-1} and 257pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k{t} R=0.2 jets, and are measured over the transverse momentum (p{T}) kinematic range of 158<p{T}<1000GeV and absolute pseudorapidity |y|<2.0. The large-radius jet constituents are further reclustered using the k{t} algorithm in order to obtain the splitting parameters, sqrt[d{12}] and DeltaR{12}, which characterize the transverse momentum scale and angular separation for the hardest splitting in the jet, respectively. The nuclear modification factor, R{AA}, obtained by comparing the Pb+Pb jet yields to those in pp collisions, is measured as a function of jet transverse momentum (p{T}) and sqrt[d{12}] or DeltaR{12}. A significant difference in the quenching of large-radius jets having single subjet and those with more complex substructure is observed. Systematic comparison of jet suppression in terms of R{AA} for different jet definitions is also provided. Presented results support the hypothesis that jets with hard internal splittings lose more energy through quenching and provide a new perspective for understanding the role of jet structure in jet suppression.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language (down) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes MEDLINE:37955510 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6059
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Author LHCb Collaboration (Aaij, R. et al); Jaimes Elles, S.J.; Jashal, B.K.; Martinez Vidal, F.; Oyanguren, A.; Rebollo De Miguel, M.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanderswood, I.
Title Search for Rare Decays of D0 Mesons into Two Muons Type Journal Article
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 4 Pages 041804 - 13pp
Keywords
Abstract A search for the very rare D^{0}mu^{+}mu^{-} decay is performed using data collected by the LHCb experiment in proton-proton collisions at sqrt[s]=7, 8, and 13TeV, corresponding to an integrated luminosity of 9fb^{-1}. The search is optimized for D^{0} mesons from D^{*+}D^{0}pi^{+} decays but is also sensitive to D^{0} mesons from other sources. No evidence for an excess of events over the expected background is observed. An upper limit on the branching fraction of this decay is set at B(D^{0}mu^{+}mu^{-})<3.1*10^{-9} at a 90% C.L. This represents the world's most stringent limit, constraining models of physics beyond the standard model.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language (down) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes MEDLINE:37566853 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6061
Permanent link to this record