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Author |
Gerbino, M.; Lattanzi, M.; Mena, O.; Freese, K. |
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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 |
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Year |
2017 |
Publication  |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
775 |
Issue |
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Pages |
239-250 |
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Keywords |
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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. |
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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; |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Language |
English |
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Original Title |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
0370-2693 |
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Conference |
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Notes |
WOS:000417190700033 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3435 |
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Author |
de Medeiros Varzielas, I.; King, S.F.; Luhn, C.; Neder, T. |
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Title |
Minima of multi-Higgs potentials with triplets of Delta(3n(2)) and Delta(6n(2)) |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
775 |
Issue |
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Pages |
303-310 |
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Keywords |
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Abstract |
We analyse the minima of scalar potentials for multi-Higgs models where the scalars are arranged as either one triplet or two triplets of the discrete symmetries A(4), S-4, Delta (27), Delta (54), as well as Delta (3n(2)) and Delta(6n2) with n > 3. The results should be useful for both multi-Higgs models involving electroweak doublets and multi-flavon models involving electroweak singlets, where in both cases the fields transform as triplets under some non-Abelian discrete symmetry. |
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Address |
[Varzielasa, Ivo de Medeiros; King, Stephen F.; Neder, Thomas] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England, Email: ivo.de@udo.edu; |
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Publisher |
Elsevier Science Bv |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Volume |
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ISSN |
0370-2693 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000417190700042 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3436 |
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Author |
Debastiani, V.R.; Liang, W.H.; Xie, J.J.; Oset, E. |
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Title |
Predictions for eta(c) -> eta pi(+)pi(-) producing f(0)(500), f(0)(980) and a(0)(980) |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
766 |
Issue |
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Pages |
59-64 |
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Keywords |
Charmonium decays; Scalar meson states; Dynamically generated resonances |
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Abstract |
We perform calculations for the eta(c) -> eta pi(+)pi(-) decay using elements of SU(3) symmetry to see the weight of different trios of pseudoscalars produced in this decay, prior to the final state interaction of the mesons. After that, the interaction of pairs of mesons, leading finally to eta pi(+)pi(-), is done using the chiral unitary approach. We evaluate the pi(+)pi(-) and pi eta mass distributions and find large and clear signals for f(0)(500), f(0)(980) and a(0)(980) excitation. The reaction is similar to the chi(c1) -> eta pi(+)pi(-), which has been recently measured at BESIII and its implementation and comparison with these predictions will be very valuable to shed light on the nature of the low mass scalar mesons. |
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Address |
[Debastiani, V. R.; Xie, Ju-Jun; Oset, E.] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Gansu, Peoples R China, Email: vinicius.rodrigues@ific.uv.es; |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000427059300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3513 |
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Author |
Gimenez-Alventosa, V.; Antunes, P.C.G.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Andreo, P. |
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Title |
Collision-kerma conversion between dose-to-tissue and dose-to-water by photon energy-fluence corrections in low-energy brachytherapy |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
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Volume |
62 |
Issue |
1 |
Pages |
146-164 |
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Keywords |
Monte Carlo; dosimetry; low-energy seed; collision-kerma; mass energy-absorption coefficients; energy-fluence correction factor |
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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). |
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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 |
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Corporate Author |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9155 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000391567700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2923 |
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Author |
Muñoz, E.; Barrio, J.; Etxebeste, A.; Ortega, P.G.; Lacasta, C.; Oliver, J.F.; Solaz, C.; Llosa, G. |
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Title |
Performance evaluation of MACACO: a multilayer Compton camera |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
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Volume |
62 |
Issue |
18 |
Pages |
7321-7341 |
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Keywords |
Compton imaging; Compton camera; continuous LaBr3 crystal; silicon photomultiplier; hadron therapy |
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Abstract |
Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide (LaBr3) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies. Images of a Na-22 and an Y-88 radioactive sources have been successfully reconstructed. The full width half maximum of the reconstructed images is below 4 mm for a Na-22 source at a distance of 5 cm. |
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Address |
[Munoz, Enrique; Barrio, John; Etxebeste, Ane; Ortega, Pablo G.; Lacasta, Carlos; Oliver, Josep F.; Solaz, Carles; Llosa, Gabriela] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: Enrique.Munoz@ific.uv.es |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9155 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000408229900003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3253 |
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