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Author Ramirez, H.; Passaglia, S.; Motohashi, H.; Hu, W.; Mena, O.
Title Reconciling tensor and scalar observables in G-inflation Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages (down) 039 - 20pp
Keywords inflation; cosmological parameters from CMBR
Abstract The simple m(2)phi(2) potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio r and measurements of the scalar spectral index n(s). Cubic Galileon interactions in the context of the Horndeski action can potentially reconcile the observables. However, we show that this cannot be achieved with only a constant Galileon mass scale because the interactions turn off too slowly, leading also to gradient instabilities after inflation ends. Allowing for a more rapid transition can reconcile the observables but moderately breaks the slow-roll approximation leading to a relatively large and negative running of the tilt alpha(s) that can be of order n(s) – 1. We show that the observables on CMB and large scale structure scales can be predicted accurately using the optimized slow-roll approach instead of the traditional slow-roll expansion. Upper limits on vertical bar alpha(s)vertical bar place a lower bound of r greater than or similar to 0.005 and, conversely, a given r places a lower bound on vertical bar alpha(s)vertical bar, both of which are potentially observable with next generation CMB and large scale structure surveys.
Address [Ramirez, Hector] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: hector.ramirez@uv.es;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000429895200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3557
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Author Stadler, J.; Boehm, C.; Mena, O.
Title Is it mixed dark matter or neutrino masses? Type Journal Article
Year 2020 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 01 Issue 1 Pages (down) 039 - 18pp
Keywords cluster counts; cosmological parameters from CMBR; cosmological parameters from LSS; neutrino masses from cosmology
Abstract In this paper, we explore a scenario where the dark matter is a mixture of interacting and non interacting species. Assuming dark matter-photon interactions for the interacting species, we find that the suppression of the matter power spectrum in this scenario can mimic that expected in the case of massive neutrinos. Our numerical studies include present limits from Planck Cosmic Microwave Background data, which render the strength of the dark matter photon interaction unconstrained when the fraction of interacting dark matter is small. Despite the large entangling between mixed dark matter and neutrino masses, we show that future measurements from the Dark Energy Instrument (DESI) could help in establishing the dark matter and the neutrino properties simultaneously, provided that the interaction rate is very close to its current limits and the fraction of interacting dark matter is at least of O (10%). However, for that region of parameter space where a small fraction of interacting DM coincides with a comparatively large interaction rate, our analysis highlights a considerable degeneracy between the mixed dark matter parameters and the neutrino mass scale.
Address [Stadler, Julia; Boehm, Celine] Univ Durham, Inst Particle Phys Phenomenol, South Rd, Durham DH1 3LE, England, Email: jstadler@mpe.mpg.de;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000528025800040 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4383
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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 (down) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language 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 5495
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Author KM3NeT Collaboration (Aiello, S. et al); Alves Garre, S.; Bariego-Quintana, A.; Carretero, V.; Calvo, D.; Cecchini, V.; Garcia Soto, A.; Gozzini, S.R.; Hernandez-Rey, J.J.; Lazo, A.; Lessing, N.; Manczak, J.; Palacios Gonzalez, J.; Pastor Gomez, E.J.; Prado, J.; Real, D.; Saina, A.; Salesa Greus, F.; Sanchez Losa, A.; Zornoza, J.D.; Zuñiga, J.
Title Search for quantum decoherence in neutrino oscillations with six detection units of KM3NeT/ORCA Type Journal Article
Year 2025 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages (down) 039 - 21pp
Keywords neutrino experiments; Frequentist statistics
Abstract Neutrinos described as an open quantum system may interact with the environment which introduces stochastic perturbations to their quantum phase. This mechanism leads to a loss of coherence along the propagation of the neutrino – a phenomenon commonly referred to as decoherence – and ultimately, to a modification of the oscillation probabilities. Fluctuations in space-time, as envisaged by various theories of quantum gravity, are a potential candidate for a decoherence-inducing environment. Consequently, the search for decoherence provides a rare opportunity to investigate quantum gravitational effects which are usually beyond the reach of current experiments. In this work, quantum decoherence effects are searched for in neutrino data collected by the KM3NeT/ORCA detector from January 2020 to November 2021. The analysis focuses on atmospheric neutrinos within the energy range of a few GeV to 100 GeV. Adopting the open quantum system framework, decoherence is described in a phenomenological manner with the strength of the effect given by the parameters Gamma(21) and Gamma(31). Following previous studies, a dependence of the type Gamma(ij) alpha (E/E-0)(n) on the neutrino energy is assumed and the cases n = -2,-1 are explored. No significant deviation with respect to the standard oscillation hypothesis is observed. Therefore, 90% CL upper limits are estimated as Gamma(21) < 4.6 center dot 10(-21) GeV and Gamma(31) < 8.4 center dot 10(-21) GeV for n = -2 and Gamma(21) < 1.9 center dot 10(-22) GeV and Gamma 31 < 2.7 center dot 10(-22) GeV for n = -1, respectively.
Address [Aiello, S.; Bruno, R.; Leonora, E.; Longhitano, F.; Randazzo, N.; Sinopoulou, A.; Tosta e Melo, I.] INFN, Sez Catania, INFN CT, Via Santa Sofia 64, I-95123 Catania, Italy
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:001458224900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6628
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Author Escudero, M.; Hooper, D.; Witte, S.J.
Title Updated collider and direct detection constraints on Dark Matter models for the Galactic Center gamma-ray excess Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages (down) 038 - 21pp
Keywords dark matter experiments; dark matter theory
Abstract Utilizing an exhaustive set of simplified models, we revisit dark matter scenarios potentially capable of generating the observed Galactic Center gamma-ray excess, updating constraints from the LUX and PandaX- II experiments, as well as from the LHC and other colliders. We identify a variety of pseudoscalar mediated models that remain consistent with all constraints. In contrast, dark matter candidates which annihilate through a spin-1 mediator are ruled out by direct detection constraints unless the mass of the mediator is near an annihilation resonance, or the mediator has a purely vector coupling to the dark matter and a purely axial coupling to Standard Model fermions. All scenarios in which the dark matter annihilates throught-channel processes are now ruled out by a combination of the constraints from LUX/ PandaX-II and the LHC.
Address [Escudero, Miguel] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: miguel.escudero@ific.uv.es;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000399455000038 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3079
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Author ANTARES Collaboration (Albert, A. et al); Alves, S.; Calvo, D.; Carretero, V.; Gozzini, R.; Hernandez-Rey, J.J.; Lazo, A.; Manczak, J.; Real, D.; Sanchez-Losa, A.; Saina, A.; Salesa Greus, F.; Zornoza, J.D.; Zuñiga, J.
Title Constraints on the energy spectrum of the diffuse cosmic neutrino flux from the ANTARES neutrino telescope Type Journal Article
Year 2024 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages (down) 038 - 27pp
Keywords neutrino astronomy; neutrino detectors; neutrino experiments
Abstract High-significance evidences of the existence of a high-energy diffuse flux of cosmic neutrinos have emerged in the last decade from several observations by the IceCube Collaboration. The ANTARES neutrino telescope took data for 15 years in the Mediterranean Sea, from 2007 to 2022, and collected a high-purity all-flavour neutrino sample. The search for a diffuse cosmic neutrino signal using this dataset is presented in this article. This final analysis did not provide a statistically significant observation of the cosmic diffuse flux. However, this is converted into limits on the properties of the cosmic neutrino spectrum. In particular, given the sensitivity of the ANTARES neutrino telescope between 1 and 50TeV, constraints on single-power-law hypotheses are derived for the cosmic diffuse flux below 20TeV, especially for power-law fits of the IceCube data with spectral index softer than 2.8.
Address
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:001319332300046 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6356
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Author Gomez-Cadenas, J.J.; Guinea, F.; Fogler, M.M.; Katsnelson, M.I.; Martin-Albo, J.; Monrabal, F.; Muñoz Vidal, J.
Title GraXe, graphene and xenon for neutrinoless double beta decay searches Type Journal Article
Year 2012 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages (down) 037 - 17pp
Keywords neutrino experiments; double beta decay
Abstract We propose a new detector concept, GraXe (to be pronounced as grace), to search for neutrinoless double beta decay in Xe-136. GraXe combines a popular detection medium in rare-event searches, liquid xenon, with a new, background-free material, grapheme. In our baseline design of GraXe, a sphere made of graphene-coated titanium mesh and filled with liquid xenon (LXe) enriched in the Xe-136 isotope is immersed in a large volume of natural LXe instrumented with photodetectors. Liquid xenon is an excellent scintillator, reasonably transparent to its own light. Graphene is transparent over a large frequency range, and impermeable to the xenon. Event position could be deduced from the light pattern detected in the photosensors. External backgrounds would be shielded by the buffer of natural LXe, leaving the ultra-radiopure internal volume virtually free of background. Industrial graphene can be manufactured at a competitive cost to produce the sphere. Enriching xenon in the isotope Xe-136 is easy and relatively cheap, and there is already near one ton of enriched xenon available in the world (currently being used by the EXO, KamLAND-Zen and NEXT experiments). All the cryogenic know-how is readily available from the numerous experiments using liquid xenon. An experiment using the GraXe concept appears realistic and affordable in a short time scale, and its physics potential is enormous.
Address [Gomez-Cadenas, J. J.; Martin-Albo, J.; Monrabal, F.; Munoz Vidal, J.] CSIC, Inst Fis Corpuscular, IFIC, Valencia 46980, Spain, Email: gomez@mail.cern.ch;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000301176000038 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 987
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Author Bertone, G.; Calore, F.; Caron, S.; Ruiz de Austri, R.; Kim, J.S.; Trotta, R.; Weniger, C.
Title Global analysis of the pMSSM in light of the Fermi GeV excess: prospects for the LHC Run-II and astroparticle experiments Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages (down) 037 - 20pp
Keywords dark matter detectors; dark matter theory; gamma ray experiments; supersymmetry and cosmology
Abstract We present a new global fit of the 19-dimensional phenomenological Minimal Supersymmetric Standard Model (pMSSM-19) that complies with all the latest experimental results from dark matter indirect, direct and accelerator dark matter searches. We show that the model provides a satisfactory explanation of the excess of gamma rays from the Galactic centre observed by the Fermi Large Area Telescope, assuming that it is produced by the annihilation of neutralinos in the Milky Way halo. We identify two regions that pass all the constraints: the first corresponds to neutralinos with a mass similar to 80 – 100 GeV annihilating into WW with a branching ratio of 95%; the second to heavier neutralinos, with mass similar to 180 – 200 GeV annihilating into (l) over barl with a branching ratio of 87%. We show that neutralinos compatible with the Galactic centre GeV excess will soon be within the reach of LHC run-II – notably through searches for charginos and neutralinos, squarks and light smuons – and of Xenon1T, thanks to its unprecedented sensitivity to spin-dependent cross-section off neutrons.
Address [Bertone, Gianfranco; Calore, Francesca; Weniger, Christoph] Univ Amsterdam, GRAPPA, Sci Pk 904, NL-1090 GL Amsterdam, Netherlands, Email: gf.bertone@gmail.com;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000393286400010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2951
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Author Barenboim, G.; Park, W.I.
Title Lepton number asymmetries and the lower bound on the reheating temperature Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 12 Issue 12 Pages (down) 037 - 13pp
Keywords cosmological neutrinos; physics of the early universe
Abstract We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around 2 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, vertical bar L vertical bar greater than or similar to O(10(-2)) (depending on the neutrino flavor) at the end of reheating.
Address [Barenboim, Gabriela] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000418672700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3430
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Author Guerrero, M.; Olmo, G.J.; Rubiera-Garcia, D.; Saez-Chillon Gomez, D.
Title Shadows and optical appearance of black bounces illuminated by a thin accretion disk Type Journal Article
Year 2021 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages (down) 036 - 19pp
Keywords GR black holes; Wormholes; modified gravity; accretion
Abstract We study the light rings and shadows of an uniparametric family of spherically symmetric geometries interpolating between the Schwarzschild solution, a regular black hole, and a traversable wormhole, and dubbed as black bounces, all of them sharing the same critical impact parameter. We consider the ray-tracing method in order to study the impact parameter regions corresponding to the direct, lensed, and photon ring emissions, finding a broadening of all these regions for black bounce solutions as compared to the Schwarzschild one. Using this, we determine the optical appearance of black bounces when illuminated by three standard toy models of optically and geometrically thin accretion disks viewed in face-on orientation.
Address [Guerrero, Merce; Rubiera-Garcia, Diego] Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain, Email: merguerr@ucm.es;
Corporate Author Thesis
Publisher 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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000686656000022 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4943
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