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Author (up) Gerbino, M.; Lattanzi, M.; Mena, O.; Freese, K.
Title A novel approach to quantifying the sensitivity of current and future cosmological datasets to the neutrino mass ordering through Bayesian hierarchical modeling Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 775 Issue Pages 239-250
Keywords
Abstract We present a novel approach to derive constraints on neutrino masses, as well as on other cosmological parameters, from cosmological data, while taking into account our ignorance of the neutrino mass ordering. We derive constraints from a combination of current as well as future cosmological datasets on the total neutrino mass M-nu and on the mass fractions f(nu),i = m(i)/M-nu (where the index i = 1, 2, 3 indicates the three mass eigenstates) carried by each of the mass eigenstates m(i), after marginalizing over the (unknown) neutrino mass ordering, either normal ordering (NH) or inverted ordering (IH). The bounds on all the cosmological parameters, including those on the total neutrino mass, take therefore into account the uncertainty related to our ignorance of the mass hierarchy that is actually realized in nature. This novel approach is carried out in the framework of Bayesian analysis of a typical hierarchical problem, where the distribution of the parameters of the model depends on further parameters, the hyperparameters. In this context, the choice of the neutrino mass ordering is modeled via the discrete hyperparameter h(type), which we introduce in the usual Markov chain analysis. The preference from cosmological data for either the NH or the IH scenarios is then simply encoded in the posterior distribution of the hyper-parameter itself. Current cosmic microwave background (CMB) measurements assign equal odds to the two hierarchies, and are thus unable to distinguish between them. However, after the addition of baryon acoustic oscillation (BAO) measurements, a weak preference for the normal hierarchical scenario appears, with odds of 4 : 3 from Planck temperature and large-scale polarization in combination with BAO (3 : 2 if small-scale polarization is also included). Concerning next-generation cosmological experiments, forecasts suggest that the combination of upcoming CMB (COrE) and BAO surveys (DESI) may determine the neutrino mass hierarchy at a high statistical significance if the mass is very close to the minimal value allowed by oscillation experiments, as for NH and a fiducial value of M-nu = 0.06 eV there is a 9 : 1 preference of normal versus inverted hierarchy. On the contrary, if the sum of the masses is of the order of 0.1 eV or larger, even future cosmological observations will be inconclusive. The innovative statistical strategy exploited here represents a very simple, efficient and robust tool to study the sensitivity of present and future cosmological data to the neutrino mass hierarchy, and a sound competitor to the standard Bayesian model comparison. The unbiased limit on M-nu we obtain is crucial for ongoing and planned neutrinoless double beta decay searches.
Address [Gerbino, Martina; Freese, Katherine] Stockholm Univ, Oskar Klein Ctr Cosmoparticle Phys, Dept Phys, AlbaNova, SE-10691 Stockholm, Sweden, Email: martina.gerbino@fysik.su.se;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000417190700033 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3435
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Author (up) Gimenez-Alventosa, V.; Antunes, P.C.G.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Andreo, P.
Title Collision-kerma conversion between dose-to-tissue and dose-to-water by photon energy-fluence corrections in low-energy brachytherapy Type Journal Article
Year 2017 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 62 Issue 1 Pages 146-164
Keywords Monte Carlo; dosimetry; low-energy seed; collision-kerma; mass energy-absorption coefficients; energy-fluence correction factor
Abstract The AAPM TG-43 brachytherapy dosimetry formalism, introduced in 1995, has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations, except in the vicinity of the source capsule. Subsequent dosimetry developments, based on Monte Carlo calculations or analytical solutions of transport equations, do not rely on the CPE assumption and determine directly the dose to different tissues. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seeds is proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences. State-of-the art Monte Carlo calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone), which in all cases include a realistic modelling of low-energy brachytherapy sources in order to benchmark the formalism proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases (e.g. bone tissue).
Address [Gimenez-Alventosa, Vicent; Antunes, Paula C. G.; Vijande, Javier; Ballester, Facundo] Univ Valencia, Dept Atom Mol & Nucl Phys, E-46100 Burjassot, Spain, Email: vijande@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 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000391567700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2923
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Author (up) Gnendiger, C.; Signer, A.; Stockinger, D.; Broggio, A.; Cherchiglia, A.L.; Driencourt-Mangin, F.; Fazio, A.R.; Hiller, B.; Mastrolia, P.; Peraro, T.; Pittau, R.; Pruna, G.M.; Rodrigo, G.; Sampaio, M.; Sborlini, G.F.R.; Torres Bobadilla, W.J.; Tramontano, F.; Ulrich, Y.; Visconti, A.
Title To d, or not to d: recent developments and comparisons of regularization schemes Type Journal Article
Year 2017 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 77 Issue 7 Pages 471 - 39pp
Keywords
Abstract We give an introduction to several regularization schemes that deal with ultraviolet and infrared singularities appearing in higher-order computations in quantum field theories. Comparing the computation of simple quantities in the various schemes, we point out similarities and differences between them.
Address [Gnendiger, C.; Signer, A.; Pruna, G. M.; Ulrich, Y.; Visconti, A.] Paul Scherrer Inst, CH-5232 Villigen, Switzerland, Email: Christoph.Gnendiger@psi.ch
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:000405609700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3207
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Author (up) Gomez Dumm, D.; Izzo Villafañe, M.F.; Noguera, S.; Pagura, V.P.; Scoccola, N.N.
Title Strong magnetic fields in nonlocal chiral quark models Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 96 Issue 11 Pages 114012 - 19pp
Keywords
Abstract We study the behavior of strongly interacting matter under a uniform intense external magnetic field in the context of nonlocal extensions of the Polyakov-Nambu-Jona-Lasinio model. A detailed description of the formalism is presented, considering the cases of zero and finite temperature. In particular, we analyze the effect of the magnetic field on the chiral restoration and deconfinement transitions, which are found to occur at approximately the same critical temperatures. Our results show that these models offer a natural framework to account for the phenomenon of inverse magnetic catalysis found in lattice QCD calculations.
Address [Gomez Dumm, D.; Izzo Villafane, M. F.] Univ Nacl La Plata, Fac Ciencias Exactas, Dept Fis, CONICET,IFLP, CC 67, RA-1900 La Plata, Buenos Aires, Argentina
Corporate Author Thesis
Publisher 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:000417833600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3419
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Author (up) Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title eta-gamma and eta(')-gamma transition form factors in a nonlocal NJL model Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 95 Issue 5 Pages 054006 - 19pp
Keywords
Abstract We study the eta and eta(') distribution amplitudes (DAs) in the context of a nonlocal SU(3)(L) circle times SUd(3)(R) chiral quark model. The corresponding Lagrangian allows us to reproduce the phenomenological values of pseudoscalar meson masses and decay constants, as well as the momentum dependence of the quark propagator arising from lattice calculations. It is found that the obtained DAs have two symmetric maxima, which arise from new contributions generated by the nonlocal character of the interactions. These DAs are then applied to the calculation of the eta-gamma and eta(')-gamma transition form factors. Implications of our results regarding higher twist corrections and/or contributions to the transition form factors originated by gluon-gluon components in the eta and eta(') mesons are discussed.
Address [Gomez Dumm, D.] Univ Nacl La Plata, Fac Ciencias Exactas, Dept Fis, IFLP,CONICET, CC 67, RA-1900 La Plata, Buenos Aires, Argentina
Corporate Author Thesis
Publisher 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:000396030600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3031
Permanent link to this record