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Author Agullo, I.; del Rio, A.; Navarro-Salas, J.
Title On the Electric-Magnetic Duality Symmetry: Quantum Anomaly, Optical Helicity, and Particle Creation Type Journal Article
Year 2018 Publication Symmetry-Basel Abbreviated Journal Symmetry-Basel
Volume 10 Issue 12 Pages 763 - 14pp
Keywords electric-magnetic duality symmetry; quantum anomalies; optical helicity; electromagnetic polarization; particle creation
Abstract It is well known that not every symmetry of a classical field theory is also a symmetry of its quantum version. When this occurs, we speak of quantum anomalies. The existence of anomalies imply that some classical Noether charges are no longer conserved in the quantum theory. In this paper, we discuss a new example for quantum electromagnetic fields propagating in the presence of gravity. We argue that the symmetry under electric-magnetic duality rotations of the source-free Maxwell action is anomalous in curved spacetimes. The classical Noether charge associated with these transformations accounts for the net circular polarization or the optical helicity of the electromagnetic field. Therefore, our results describe the way the spacetime curvature changes the helicity of photons and opens the possibility of extracting information from strong gravitational fields through the observation of the polarization of photons. We also argue that the physical consequences of this anomaly can be understood in terms of the asymmetric quantum creation of photons by the gravitational field.
Address [Agullo, Ivan] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA, Email: agullo@lsu.edu;
Corporate Author Thesis
Publisher (down) Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-8994 ISBN Medium
Area Expedition Conference
Notes WOS:000454725100101 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3867
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Author Chen, Y.H.; Yao, D.L.; Zheng, H.Q.
Title A Study of rho-omega Mixing in Resonance Chiral Theory Type Journal Article
Year 2018 Publication Communications in Theoretical Physics Abbreviated Journal Commun. Theor. Phys.
Volume 69 Issue 1 Pages 50-58
Keywords Chiral Lagrangians; vector mesons; 1/N-C expansion
Abstract The strong and electromagnetic corrections to rho-omega mixing are calculated using an SU(2) version of resonance chiral theory up to next-to-leading orders in 1/N-C expansion, respectively. Up to our accuracy, the effect of the momentum dependence of rho-omega mixing is incorporated due to the inclusion of loop contributions. We analyze the impact of rho-omega mixing on the pion vector form factor by performing numerical fit to the data extracted from e(+)e(-) -> pi(+)pi(-) and tau -> nu(tau)2 pi, while the decay width of omega -> pi(+)pi(-) is taken into account as a constraint. It is found that the momentum dependence is significant in a good description of the experimental data. In addition, based on the fitted values of the involved parameters, we analyze the decay width of omega -> pi(+)pi(-), which turns out to be highly dominated by the rho-omega mixing effect.
Address [Chen, Yun-Hua] Univ Sci & Technol Beijing, Sch Math & Phys, Beijing 100083, Peoples R China, Email: yhchen@ustb.edu.cn;
Corporate Author Thesis
Publisher (down) Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0253-6102 ISBN Medium
Area Expedition Conference
Notes WOS:000422832600010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3453
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Author Villanueva-Domingo, P.; Gnedin, N.Y.; Mena, O.
Title Warm Dark Matter and Cosmic Reionization Type Journal Article
Year 2018 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 852 Issue 2 Pages 139 - 7pp
Keywords cosmology: theory; galaxies: formation; intergalactic medium; large-scale structure of universe; methods: numerical
Abstract In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3. keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn-Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in both CDM and WDM models, the full distribution of Gunn-Peterson optical depth retains the strong signature of delayed reionization in the WDM model. However, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent.
Address [Villanueva-Domingo, Pablo; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: gnedin@fnal.gov
Corporate Author Thesis
Publisher (down) Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000422865600009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3455
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Author ANTARES Collaboration (Albert, A. et al); Barrios-Marti, J.; Coleiro, A.; Hernandez-Rey, J.J.; Illuminati, G.; Lotze, M.; Tönnis, C.; Zornoza, J.D.; Zuñiga, J.
Title All-flavor Search for a Diffuse Flux of Cosmic Neutrinos with Nine Years of ANTARES Data Type Journal Article
Year 2018 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 853 Issue 1 Pages L7 - 5pp
Keywords astroparticle physics; neutrinos
Abstract The ANTARES detector is at present the most sensitive neutrino telescope in the northern hemisphere. The highly significant cosmic neutrino excess observed by the Antarctic IceCube detector can be studied with ANTARES, exploiting its complementing field of view, exposure, and lower energy threshold. Searches for an all-flavor diffuse neutrino signal, covering nine years of ANTARES data taking, are presented in this Letter. Upward-going events are used to reduce the atmospheric muon background. This work includes for the first time in ANTARES both track-like (mainly nu mu) and shower-like (mainly nu(e)) events in this kind of analysis. Track-like events allow for an increase of the effective volume of the detector thanks to the long path traveled by muons in rock and/ or sea water. Shower-like events are well reconstructed only when the neutrino interaction vertex is close to, or inside, the instrumented volume. A mild excess of high-energy events over the expected background is observed in nine years of ANTARES data in both samples. The best fit for a single power-law cosmic neutrino spectrum, in terms of perflavor flux at 100 TeV, is Phi(1f)(0) (100 TeV) = (1.7 +/- 1.0) x 10(-18) GeV-1 cm(-2) s(-1) sr(-1) with spectral index Gamma = 2.4(-0.4)(+0.5) .The null cosmic flux assumption is rejected with a significance of 1.6 sigma .
Address [Albert, A.; Drouhin, D.; Racca, C.] Inst Univ Technol Colmar, Univ Haute Alsace, GRPHE, 34 Rue Grillenbreit BP, F-505686800 Colmar, France, Email: lfusco@bo.infn.it;
Corporate Author Thesis
Publisher (down) Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-8205 ISBN Medium
Area Expedition Conference
Notes WOS:000423182700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3456
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Author Double Chooz collaboration (Abrahao, T. et al); Novella, P.
Title Novel event classification based on spectral analysis of scintillation waveforms in Double Chooz Type Journal Article
Year 2018 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 13 Issue Pages P01031 - 26pp
Keywords Digital signal processing (DSP); Particle identification methods; Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators); Neutrino detectors
Abstract Liquid scintillators are a common choice for neutrino physics experiments, but their capabilities to perform background rejection by scintillation pulse shape discrimination is generally limited in large detectors. This paper describes a novel approach for a pulse shape based event classification developed in the context of the Double Chooz reactor antineutrino experiment. Unlike previous implementations, this method uses the Fourier power spectra of the scintillation pulse shapes to obtain event-wise information. A classification variable built from spectral information was able to achieve an unprecedented performance, despite the lack of optimization at the detector design level. Several examples of event classification are provided, ranging from differentiation between the detector volumes and an efficient rejection of instrumental light noise, to some sensitivity to the particle type, such as stopping muons, ortho-positronium formation, alpha particles as well as electrons and positrons. In combination with other techniques the method is expected to allow for a versatile and more efficient background rejection in the future, especially if detector optimization is taken into account at the design level.
Address [Abrahao, T.; dos Anjos, J. C.; Lima, H.; Pepe, I.; Wagner, S.] Ctr Brasileiro Pesquisas Fis, BR-22290180 Rio De Janeiro, Brazil, Email: stefan.wagner@apc.in2p3.fr
Corporate Author Thesis
Publisher (down) Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000423783800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3466
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