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Author Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y.F. url  doi
openurl 
  Title Updated global 3+1 analysis of short-baseline neutrino oscillations Type Journal Article
  Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue (up) 6 Pages 135 - 38pp  
  Keywords Neutrino Physics; Beyond Standard Model  
  Abstract We present the results of an updated fit of short-baseline neutrino oscillation data in the framework of 3+1 active-sterile neutrino mixing. We first consider v(e) and (v) over bar (e) disappearance in the light of the Gallium and reactor anomalies. We discuss the implications of the recent measurement of the reactor (v) over bar (e) spectrum in the NEOS experiment, which shifts the allowed regions of the parameter space towards smaller values of |U-e1|(2). The beta-decay constraints of the Mainz and Troitsk experiments allow us to limit the oscillation length between about 2 cm and 7 m at 3 sigma for neutrinos with an energy of 1 MeV. The corresponding oscillations can be discovered in a model-independent way in ongoing reactor and source experiments by measuring v(e) and (v) over bar (e), disappearance as a function of distance. We then consider the global fit of the data on short-baseline v(mu)((-)) -> v(e)((-)) transitions in the light of the LSND anomaly, taking into account the constraints from v(e)(( )) and v(mu)((-)) disappearance experiments, including the recent data of the MINOS and IceCube experiments. The combination of the NEOS constraints on |U-e4|(2) and the MINOS and IceCube constraints on |U-mu 4|(2) lead to an unacceptable appearance-disappearance tension which becomes tolerable only in a pragmatic fit which neglects the MiniBooNE low-energy anomaly. The minimization of the global chi(2) in the space of the four mixing parameters Delta m(41)(2), |U-e4|(2), |U-mu 4|(2) and |U-4 tau|(2) leads to three allowed regions with narrow Delta m(41)(2) widths at Delta m(41)(2) approximate to 1.7 (best-fit), 1.3 (at 2 sigma), 2.4 (at 3 sigma) eV(2). The effective amplitude of short-baseline v(mu)((-)) -> v(e)((-)) oscillations is limited by 0.00048 less than or similar to sin(2) 2 nu(e mu) less than or similar to 0.0020 at 3 sigma The restrictions of the allowed regions of the mixing parameters with respect to our previous global fits are mainly due to the NEOS constraints. We present a comparison of the allowed regions of the mixing parameters with the sensitivities of ongoing experiments, which show that it is likely that these experiments will determine in a definitive way if the reactor, Gallium and LSND anomalies are due to active-sterile neutrino oscillations or not.  
  Address [Gariazzo, S.] Univ Valencia, CSIC, Inst Fis Corpusc, Valencia, Spain, Email: gariazzo@ific.uv.es;  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404627200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3190  
Permanent link to this record
 

 
Author Gariazzo, S. url  doi
openurl 
  Title Constraining power of open likelihoods, made prior-independent Type Journal Article
  Year 2020 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 80 Issue (up) 6 Pages 552 - 6pp  
  Keywords  
  Abstract One of the most criticized features of Bayesian statistics is the fact that credible intervals, especially when open likelihoods are involved, may strongly depend on the prior shape and range. Many analyses involving open likelihoods are affected by the eternal dilemma of choosing between linear and logarithmic prior, and in particular in the latter case the situation is worsened by the dependence on the prior range under consideration. In this letter, we revive a simple method to obtain constraints that depend neither on the prior shape nor range and, using the tools of Bayesian model comparison, extend it to overcome the possible dependence of the bounds on the choice of free parameters in the numerical analysis. An application to the case of cosmological bounds on the sum of the neutrino masses is discussed as an example.  
  Address [Gariazzo, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient UV,C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: gariazzo@ific.uv.es  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000542940000007 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4446  
Permanent link to this record
 

 
Author Gariazzo, S.; de Salas, P.F.; Pastor, S. url  doi
openurl 
  Title Thermalisation of sterile neutrinos in the early universe in the 3+1 scheme with full mixing matrix Type Journal Article
  Year 2019 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 07 Issue (up) 7 Pages 014 - 30pp  
  Keywords cosmological neutrinos; neutrino properties; particle physics – cosmology connection; physics of the early universe  
  Abstract In the framework of a 3+1 scheme with an additional inert state, we consider the thermalisation of sterile neutrinos in the early Universe taking into account the full 4 x 4 mixing matrix. The evolution of the neutrino energy distributions is found solving the momentum-dependent kinetic equations with full diagonal collision terms, as in previous analyses of flavour neutrino decoupling in the standard case. The degree of thermalisation of the sterile state is shown in terms of the effective number of neutrinos, N-eff, and its dependence on the three additional mixing angles (theta(14), theta(24), theta(34)) and on the squared mass difference Delta m(41)(2) is discussed. Our results are relevant for fixing the contribution of a fourth light neutrino species to the cosmological energy density, whose value is very well constrained by the final Planck analysis. For the preferred region of active-sterile mixing parameters from short-baseline neutrino experiments, we find that the fourth state is fully thermalised (N-eff similar or equal to 4).  
  Address [Gariazzo, S.; Pastor, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: gariazzo@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:000474782100001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4076  
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Author PTOLEMY Collaboration (Betti, M.G. et al); Gariazzo, S.; Pastor, S. url  doi
openurl 
  Title Neutrino physics with the PTOLEMY project: active neutrino properties and the light sterile case Type Journal Article
  Year 2019 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 07 Issue (up) 7 Pages 047 - 31pp  
  Keywords cosmological neutrinos; neutrino detectors; particle physics – cosmology connection; physics of the early universe  
  Abstract The PTOLEMY project aims to develop a scalable design for a Cosmic Neutrino Background (CNB) detector, the first of its kind and the only one conceived that can look directly at the image of the Universe encoded in neutrino background produced in the first second after the Big Bang. The scope of the work for the next three years is to complete the conceptual design of this detector and to validate with direct measurements that the non-neutrino backgrounds are below the expected cosmological signal. In this paper we discuss in details the theoretical aspects of the experiment and its physics goals. In particular, we mainly address three issues. First we discuss the sensitivity of PTOLEMY to the standard neutrino mass scale. We then study the perspectives of the experiment to detect the CNB via neutrino capture on tritium as a function of the neutrino mass scale and the energy resolution of the apparatus. Finally, we consider an extra sterile neutrino with mass in the eV range, coupled to the active states via oscillations, which has been advocated in view of neutrino oscillation anomalies. This extra state would contribute to the tritium decay spectrum, and its properties, mass and mixing angle, could be studied by analyzing the features in the beta decay electron spectrum.  
  Address [Betti, M. G.; Cavoto, G.; Mancini-Terracciano, C.; Mariani, C.; Polosa, A. D.; Rago, I] Univ Roma La Sapienza, Rome, Italy, Email: pabferde@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:000478735300006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4097  
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Author Di Valentino, E.; Gariazzo, S.; Mena, O.; Vagnozzi, S. url  doi
openurl 
  Title Soundness of dark energy properties Type Journal Article
  Year 2020 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 07 Issue (up) 7 Pages 045 - 45pp  
  Keywords supernova type Ia – standard candles; dark energy experiments; cosmological parameters from CMBR; cosmological parameters from LSS  
  Abstract Type Ia Supernovae (SNeIa) used as standardizable candles have been instrumental in the discovery of cosmic acceleration, usually attributed to some form of dark energy (DE). Recent studies have raised the issue of whether intrinsic SNeIa luminosities might evolve with redshift. While the evidence for cosmic acceleration is robust to this possible systematic, the question remains of how much the latter can affect the inferred properties of the DE component responsible for cosmic acceleration. This is the question we address in this work. We use SNeIa distance moduli measurements from the Pantheon and JLA samples. We consider models where the DE equation of state is a free parameter, either constant or time-varying, as well as models where DE and dark matter interact, and finally a model-agnostic parametrization of effects due to modified gravity (MG). When SNeIa data are combined with Cosmic Microwave Background (CMB) temperature and polarization anisotropy measurements, we find strong degeneracies between parameters governing the SNeIa systematics, the DE parameters, and the Hubble constant H-0. These degeneracies significantly broaden the DE parameter uncertainties, in some cases leading to O(sigma) shifts in the central values. However, including low-redshift Baryon Acoustic Oscillation and Cosmic Chronometer measurements, as well as CMB lensing measurements, considerably improves the previous constraints, and the only remaining effect of the examined systematic is a less than or similar to 40% broadening of the uncertainties on the DE parameters. The constraints we derive on the MG parameters are instead basically unaffected by the systematic in question. We therefore confirm the overall soundness of dark energy properties.  
  Address [Di Valentino, Eleonora] Univ Manchester, Sch Phys & Astron, Jodrell Bank Ctr Astrophys, Oxford Rd, Manchester M13 9PL, Lancs, England, Email: eleonora.divalentino@mancher.ac.uk;  
  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:000551883400049 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4475  
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