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1. Predictions for the Majorana CP Violation Phases in the Neutrino Mixing Matrix and Neutrinoless Double Beta Decay

Author

Girardi, I., Petcov, S. T., and Titov, A. V.

Subjects
High Energy Physics - Phenomenology
Abstract

We obtain predictions for the Majorana phases $\alpha_{21}/2$ and $\alpha_{31}/2$ of the $3\times 3$ unitary neutrino mixing matrix $U = U_e^{\dagger} \, U_{\nu}$, $U_e$ and $U_{\nu}$ being the $3\times 3$ unitary matrices resulting from the diagonalisation of the charged lepton and neutrino Majorana mass matrices, respectively. We focus on forms of $U_e$ and $U_{\nu}$ permitting to express $\alpha_{21}/2$ and $\alpha_{31}/2$ in terms of the Dirac phase $\delta$ and the three neutrino mixing angles of the standard parametrisation of $U$, and the angles and the two Majorana-like phases $\xi_{21}/2$ and $\xi_{31}/2$ present, in general, in $U_{\nu}$. The concrete forms of $U_{\nu}$ considered are fixed by, or associated with, symmetries (tri-bimaximal, bimaximal, etc.), so that the angles in $U_{\nu}$ are fixed. For each of these forms and forms of $U_e$ that allow to reproduce the measured values of the three neutrino mixing angles $\theta_{12}$, $\theta_{23}$ and $\theta_{13}$, we derive predictions for phase differences $(\alpha_{21}/2 - \xi_{21}/2)$, $(\alpha_{31}/2 - \xi_{31}/2)$, etc., which are completely determined by the values of the mixing angles. We show that the requirement of generalised CP invariance of the neutrino Majorana mass term implies $\xi_{21} = 0$ or $\pi$ and $\xi_{31} = 0$ or $\pi$. For these values of $\xi_{21}$ and $\xi_{31}$ and the best fit values of $\theta_{12}$, $\theta_{23}$ and $\theta_{13}$, we present predictions for the effective Majorana mass in neutrinoless double beta decay for both neutrino mass spectra with normal and inverted ordering., Comment: 59 pages, includes 8 figures and 6 tables; a discussion of the effects of the uncertainties in the values of neutrino mixing angles on the predictions for the Majorana phases and four new related figures (two in the main text and two in a new appendix) added

Published
2016
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2. Leptonic Dirac CP Violation Predictions from Residual Discrete Symmetries

Author

Girardi, I., Petcov, S. T., Stuart, Alexander J., and Titov, A. V.

Subjects
High Energy Physics - Phenomenology
Abstract

Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group $G_f$, and that $G_f$ is broken to specific residual symmetries $G_e$ and $G_\nu$ of the charged lepton and neutrino mass terms, we derive sum rules for the cosine of the Dirac phase $\delta$ of the neutrino mixing matrix $U$. The residual symmetries considered are: i) $G_e = Z_2$ and $G_{\nu} = Z_n$, $n > 2$ or $Z_n \times Z_m$, $n,m \geq 2$; ii) $G_e = Z_n$, $n > 2$ or $Z_n \times Z_m$, $n,m \geq 2$ and $G_{\nu} = Z_2$; iii) $G_e = Z_2$ and $G_{\nu} = Z_2$; iv) $G_e$ is fully broken and $G_{\nu} = Z_n$, $n > 2$ or $Z_n \times Z_m$, $n,m \geq 2$; and v) $G_e = Z_n$, $n > 2$ or $Z_n \times Z_m$, $n,m \geq 2$ and $G_{\nu}$ is fully broken. For given $G_e$ and $G_\nu$, the sum rules for $\cos\delta$ thus derived are exact, within the approach employed, and are valid, in particular, for any $G_f$ containing $G_e$ and $G_\nu$ as subgroups. We identify the cases when the value of $\cos\delta$ cannot be determined, or cannot be uniquely determined, without making additional assumptions on unconstrained parameters. In a large class of cases considered the value of $\cos\delta$ can be unambiguously predicted once the flavour symmetry $G_f$ is fixed. We present predictions for $\cos\delta$ in these cases for the flavour symmetry groups $G_f = S_4$, $A_4$, $T^\prime$ and $A_5$, requiring that the measured values of the 3-neutrino mixing parameters $\sin^2\theta_{12}$, $\sin^2\theta_{13}$ and $\sin^2\theta_{23}$, taking into account their respective $3\sigma$ uncertainties, are successfully reproduced., Comment: 62 pages, includes 6 figures and 14 tables; results unchanged; sections 7 and 8 revised; typos corrected; matches published version

Published
2015
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3. Predictions for the Dirac CP Violation Phase in the Neutrino Mixing Matrix

Author

Girardi, I., Petcov, S. T., and Titov, A. V.

Subjects
High Energy Physics - Phenomenology
Abstract

Using the fact that the neutrino mixing matrix $U = U^\dagger_{e}U_{\nu}$, where $U_{e}$ and $U_{\nu}$ result from the diagonalisation of the charged lepton and neutrino mass matrices, we analyse the predictions based on the sum rules which the Dirac phase $\delta$ present in $U$ satisfies when $U_{\nu}$ has a form dictated by, or associated with, discrete flavour symmetries and $U_e$ has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to $U_{\nu}$, so that the reactor, atmospheric and solar neutrino mixing angles $\theta_{13}$, $\theta_{23}$ and $\theta_{12}$ have values compatible with the current data., Comment: 10 pages, 3 figures, one table; to be published in the Proceedings of the International Conference on Massive Neutrinos, Nanyang Technological University, Singapore, 9-13 February, 2015

Published
2015
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4. Predictions for the Leptonic Dirac CP Violation Phase: a Systematic Phenomenological Analysis

Author

Girardi, I., Petcov, S. T., and Titov, A. V.

Subjects
High Energy Physics - Phenomenology
Abstract

We derive predictions for the Dirac phase $\delta$ present in the $3\times 3$ unitary neutrino mixing matrix $U = U_e^{\dagger} \, U_{\nu}$, where $U_e$ and $U_{\nu}$ are $3\times 3$ unitary matrices which arise from the diagonalisation, respectively, of the charged lepton and the neutrino mass matrices. We consider forms of $U_e$ and $U_{\nu}$ allowing us to express $\delta$ as a function of three neutrino mixing angles, present in $U$, and the angles contained in $U_{\nu}$. We consider several forms of $U_{\nu}$ determined by, or associated with, symmetries, tri-bimaximal, bimaximal, etc., for which the angles in $U_{\nu}$ are fixed. For each of these forms and forms of $U_e$ allowing one to reproduce the measured values of the neutrino mixing angles, we construct the likelihood function for $\cos \delta$, using i) the latest results of the global fit analysis of neutrino oscillation data, and ii) the prospective sensitivities on the neutrino mixing angles. Our results, in particular, confirm the conclusion, reached in earlier similar studies, that the measurement of the Dirac phase in the neutrino mixing matrix, together with an improvement of the precision on the mixing angles, can provide unique information as regards the possible existence of symmetry in the lepton sector., Comment: 37 pages, includes 8 figures and 6 tables; references added; typos corrected; matches published version

Published
2015
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5. Probing new physics scenarios in accelerator and reactor neutrino experiments

Author

Di Iura, A., Girardi, I., and Meloni, D.

Subjects
High Energy Physics - Phenomenology
Abstract

We perform a detailed combined fit to the $\overline \nu_e \rightarrow \overline \nu_e$ disappearence data of the Daya Bay experiment and the appearance $\nu_{\mu} \rightarrow \nu_{e}$ and disappearance $\nu_{\mu} \rightarrow \nu_{\mu}$ data of the Tokai to Kamioka (T2K) one in the presence of two models of new physics affecting neutrino oscillations, namely a model where sterile neutrinos can propagate in a large compactified extra dimension and a model where non-standard interactions (NSI) affect the neutrino production and detection. We find that the Daya Bay $\oplus$ T2K data combination constrains the largest radius of the compactified extra dimensions to be $R\lesssim 0.17$ $\mu {\rm m}$ at 2$\sigma$ C.L. (for the inverted ordering of the neutrino mass spectrum) and the relevant NSI parameters in the range ${\mathcal O}(10^{-3})-{\mathcal O}(10^{-2})$, for particular choices of the charged parity violating phases., Comment: 18 pages, 10 figures, 4 tables; typos corrected; matches published version

Published
2014
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6. Determining the Dirac CP Violation Phase in the Neutrino Mixing Matrix from Sum Rules

Author

Girardi, I., Petcov, S. T., and Titov, A. V.

Subjects
High Energy Physics - Phenomenology
Abstract

Using the fact that the neutrino mixing matrix $U = U^\dagger_{e}U_{\nu}$, where $U_{e}$ and $U_{\nu}$ result from the diagonalisation of the charged lepton and neutrino mass matrices, we analyse the sum rules which the Dirac phase $\delta$ present in $U$ satisfies when $U_{\nu}$ has a form dictated by flavour symmetries and $U_e$ has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to $U_{\nu}$, so that reactor, atmospheric and solar neutrino mixing angles $\theta_{13}$, $\theta_{23}$ and $\theta_{12}$ have values compatible with the current data. The following symmetry forms are considered: i) tri-bimaximal (TBM), ii) bimaximal (BM) (or corresponding to the conservation of the lepton charge $L' = L_e - L_\mu - L_{\tau}$ (LC)), iii) golden ratio type A (GRA), iv) golden ratio type B (GRB), and v) hexagonal (HG). We investigate the predictions for $\delta$ in the cases of TBM, BM (LC), GRA, GRB and HG forms using the exact and the leading order sum rules for $\cos\delta$ proposed in the literature, taking into account also the uncertainties in the measured values of $\sin^2\theta_{12}$, $\sin^2\theta_{23}$ and $\sin^2\theta_{13}$. This allows us, in particular, to assess the accuracy of the predictions for $\cos\delta$ based on the leading order sum rules and its dependence on the values of the indicated neutrino mixing parameters when the latter are varied in their respective 3$\sigma$ experimentally allowed ranges., Comment: 37 pages, includes 18 figures and 10 tables; results in v.4 unchanged; typos corrected; matches published version.

Published
2014
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7. The Daya Bay and T2K results on $\sin^2 2 \theta_{13}$ and Non-Standard Neutrino Interactions

Author

Girardi, I., Meloni, D., and Petcov, S. T.

Subjects
High Energy Physics - Phenomenology
Abstract

We show that the relatively large best fit value of $\sin^2 2 \theta_{13} = 0.14 \, (0.17)$ measured in the T2K experiment for fixed values of i) the Dirac CP violation phase $\delta = 0$, and ii) the atmospheric neutrino mixing parameters $\theta_{23} = \pi/4$, $|\Delta m^2_{32}| = 2.4 \times 10^{-3} \; {\rm eV}^2$, can be reconciled with the Daya Bay result $\sin^2 2 \theta_{13} = 0.090 \pm 0.009$ if the effects of non-standard neutrino interactions (NSI) in the relevant $\bar \nu_e \to \bar \nu_e$ and $\nu_\mu \to \nu_e$ oscillation probabilities are taken into account., Comment: 12 pages, 5 figures, results unchanged; typos corrected; version published in Nuclear Physics B

Published
2014
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8. Constraining new physics scenarios in neutrino oscillations from Daya Bay data

Author

Girardi, I. and Meloni, D.

Subjects
High Energy Physics - Phenomenology
Abstract

We perform for the first time a detailed fit to the $\bar \nu_e \to \bar \nu_e$ disappearance data of the Daya Bay experiment to constrain the parameter space of models where sterile neutrinos can propagate in a large compactified extra dimension (LED) and models where non-standard interactions affect the neutrino production and detection (NSI). We find that the compactification radius $R$ in LED scenarios can be constrained at the level of $0.57 \, \mu m$ for normal ordering and of $0.19\, \mu m$ for inverted ordering, at 2$\sigma$ confidence level. For the NSI model, reactor data put a strong upper bound on the parameter $\varepsilon_{ee}$ at the level of $\sim 10^{-3}$, whereas the main effect of $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ is a worsening of the determination of $\theta_{13}$., Comment: 5 pages, 2 figures

Published
2014
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13. Influence of Surface Sealants on Microleakage in Composite Restorations

Author

Urquía-Morales, C., Brasca, N., Girardi, M., Bonnin, C., Ríos, A., Girardi, I., Chávez-Lozada, J., and Delgado, A.

Subjects
sellantes de superficie, surface sealants, microleakage, composites, microfiltración
Abstract

Polymerization shrinkage of composites can generate stress that results in the formation of microgaps at the resin-enamel interface and marginal leakage. The aim of the present work was to evaluate the influence of surface sealants on microleakage in composite restorations. Enamel-dentin occlusal cavities were prepared in 30 non-carious upper and lower premolars. The cavities were restored with One Coat Bond SL and Brilliant New Generation (Coletene), following the manufacturers' instructions, and polished appropriately. The samples were randomly assigned to one of the following six treatment groups: Group I (Control-no sealant); Group II: Single Bond (3M/ESPE); Group III: Perma Seal (Ultradent); Group IV: Heliobond (Vivadent); Group V: Biscover LV (Bisco); Group VI: Bioforty (Biodinâmica). The samples were then immersed in 2 % aqueous methylene blue solution for 48 hours, and thermocycled 100 times from 5 ºC to 55 ºC. The obtained specimens were ground in a bucco-palatal orientation to reach the medial plane, and observed under a stereoscopic loupe at 40X. The degree of microleakage was evaluated by assessing the penetration of the dye to the tooth-restoration interface, using a 0 to 3 grading scale. The obtained data were analyzed using the Kruskal-Wallis non-parametric test. Significant differences were observed between all rebonded groups and the control group; no differences were observed among Single Bond, Perma Seal and bioforty, or between Heliobond and Biscover LV. It would seem convenient to apply a surface sealant over composite restorations to improve marginal integrity and reduce microleakage. RESUMEN: La contracción de polimerización de los composites puede generar fuerzas que determinan la formación de microbrechas en la interfase resina-esmalte y filtración marginal. El objetivo de este trabajo fue evaluar la influencia de los sellantes de superficie, en restauraciones de composite, sobre la microfiltración. Se utilizaron 30 premolares superiores e inferiores, libres de caries, donde se realizaron preparaciones oclusales amelodentinarias que fueron obturadas con One Coat Bond SL y Brilliant New Generation (Coletene), siguiendo las indicaciones del fabricante y pulidas adecuadamente. Luego las muestras se distribuyeron aleatoriamente en seis grupos, según los materiales experimentales: Grupo I (Control), Grupo II: Single Bond (3M/ESPE), Grupo III: Perma Seal (Ultradent), Grupo IV: Heliobond (Vivadent), Grupo V: Biscover LV (Bisco), Grupo VI: bioforty (biodinámica). Posteriormente las piezas fueron sometidas a ciclaje térmico por 100 ciclos entre 5 ºC y 55 ºC, sumergidas en una solución acuosa de azul de metileno al 2 % durante 48 horas y desgastadas en sentido V-P, hasta el plano medial, para ser observadas con lupa estereoscópica a 40 X. El grado de filtración se evaluó por la penetración del colorante en la interfase diente-restauración en una escala de O a 3. Los datos obtenidos fueron analizados mediante la muestra no paramétrica de Kruskal-Wallis. Se encontraron diferencias significativas de todos los grupos con respecto al grupo control (p= 0,0167), no existiendo significación entre Single Bond, Perma Seal y bioforty ni entre Heliobond y Biscover LV. En restauraciones de composite, sería conveniente la aplicación de sellantes de superficie para mejorar la integridad marginal y disminuir la microfiltración.

Published
2017

14. Search for new physics in reactor and accelerator experiments

Author

DI IURA, ANDREA GIUSEPPE, MELONI, DAVIDE, Girardi, I., A. Di Iura, I. Girardi and D. Meloni, DI IURA, ANDREA GIUSEPPE, Girardi, I., and Meloni, Davide

Subjects
Physics and Astronomy (miscellaneous), High Energy Physics::Phenomenology, High Energy Physics::Experiment, Astronomy and Astrophysic
Abstract

We consider two scenarios of New Physics: the Large Extra Dimensions (LED), where sterile neutrinos can propagate in a (4 + d)-dimensional space-time, and the Non Standard Interactions (NSI), where the neutrino interactions with ordinary matter are parametrized at low energy in terms of effective flavour-dependent complex couplings ϵαβ . We study how these models have an impact on oscillation parameters in reactor and accelerator experiments.

Published
2016

15. The Daya Bay and T2K results on sin2⁡2θ13 and non-standard neutrino interactions

Author

Girardi, I.(SISSA/INFN, Via Bonomea 265, Trieste, 34136, Italy), Meloni, D.(Dipartimento di Matematica e Fisica, Università di Roma Tre, Via della Vasca Navale 84, Rome, I-00146, Italy), and Petcov, S.T.(SISSA/INFN, Via Bonomea 265, Trieste, 34136, Italy)

Subjects
lcsh:QC770-798, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity
Abstract

We show that the relatively large best fit value of sin2⁡2θ13=0.14(0.17) measured in the T2K experiment for fixed values of i) the Dirac CP violation phase δ=0, and ii) the atmospheric neutrino mixing parameters θ23=π/4, |Δm322|=2.4×10−3 eV2, can be reconciled with the Daya Bay result sin2⁡2θ13=0.090±0.009 if the effects of non-standard neutrino interactions (NSI) in the relevant ν¯e→ν¯e and νμ→νe oscillation probabilities are taken into account.

Published
2014

18. The Daya Bay and T2K results on $\sin^2 2 ��_{13}$ and Non-Standard Neutrino Interactions

Author

Girardi, I., Meloni, D., and Petcov, S. T.

Subjects
High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences
Abstract

We show that the relatively large best fit value of $\sin^2 2 ��_{13} = 0.14 \, (0.17)$ measured in the T2K experiment for fixed values of i) the Dirac CP violation phase $��= 0$, and ii) the atmospheric neutrino mixing parameters $��_{23} = ��/4$, $|��m^2_{32}| = 2.4 \times 10^{-3} \; {\rm eV}^2$, can be reconciled with the Daya Bay result $\sin^2 2 ��_{13} = 0.090 \pm 0.009$ if the effects of non-standard neutrino interactions (NSI) in the relevant $\bar ��_e \to \bar ��_e$ and $��_��\to ��_e$ oscillation probabilities are taken into account., 12 pages, 5 figures, results unchanged; typos corrected; version published in Nuclear Physics B

Published
2014
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20. Microleakage of a self- adhesive flowable resin as pit and fissure sealant

Author

Brasca N, Bonnin C, Ríos A, Girardi I, Girardi M, Delgado A, Chávez Lozada J, Urquía Morales M del C.

Subjects
SELF ADHESIVE RESIN, SEALANTS, MICROLEAKAGE
Abstract

One of the desireable properties of pit and fissure sealants is to provide an adequate marginal seal to prevent microleakage. The objective was to evaluate the sealing ability of a self-adhesive flowable resin , based on the degree of marginal leakage and compared with a conventional resin sealant. Materials and method: 18 premolars were used, no caries, extracted for orthodontic reasons. The structural defects were widen using a fisurotomía bur STF/18013 (SS White), with super high speed and intense water cooling. Samples were randomized into 3 groups according to the experimental materials; GROUP 1: Clinpro (3M/ESPE), prior conditioning with 35% phosphoric acid; GROUP 2: Clinpro (3M/ESPE), prior conditioning with 35% phosphoric acid and placement of an adhesive (Adper Single Bond 2 - 3M / ESPE) and GROUP 3: Dyad Flow (Kerr) with enamel conditioning prior. Afterwards the samples were thermocycled for 300 cycles between 5° and 55 ° C for 30 seconds in each bath and immersed in a 2% solution of methylene blue during 24 hours at a temperature of 37 ° C. Were rinsed thoroughly with running water and sectioned (Isomet 1000, Buehler) in VP plane obtaining two halves to be observed with optical microscope at 40 X magnification. The degree of microleakage was determined according to the depth of dye penetration, on a scale of 0 to 3. The data were analyzed by Kruskal-Wallis non parametric test, showing significant differences (p = 0.0006). Results: The Mann Whitney test revealed no statistically significant differences between group 1 (0.25) and group 2 (0.33) but both with respect to group 3 (1,42). Conclusion: The self- adhesive flowable resin has a sealability lower than conventional sealant because the higher degree of leakage was observed in Group 3.This work has been subsidized by Secyt (UNC).Keywords: self adhesive resin, sealants, microleakage. www.dentalresearch.org publishedVersion Otras Ciencias de la Salud

Published
2013

21. Promotion of oral health between grandparents and grandchildren in the school setting

Author

Vera, M., Cacciamano, J., Brasca, N., Girardi, I., Urquia Morales, M. del C., and Farah, M.

Subjects
Prevention, Oral health in children and older
Abstract

Within the cultural context represented by two age groups ( grandparents and students in 6th and 2nd grade) Of the Institute Parish San Roque de Córdoba , adults throughout their life experience , transmitted to children , what would be good to know for achieving oral health , thus promoting come disease control in cavities. Purpose: to strengthen social relationships and family ties between grandparents and grandchildren with a formal education process of double track, according to the interests and needs, where both worked to modify the risk factors of the disease. Methods: FIRST STAGE design and implementation of a questionnaire to diagnose children´s oral situation. The validation of the instrument was performed by a panel of experts, field validation and pilot test to Cronbach ´s coefficient alpha was applied to measure reliability. SECOND STAGE, working together with grandparents in intervention strategies and educational material to develop with their grandchildren in the prevention of oral health . THIRD STAGE The planned strategies were carried out. FOURTH STAGE, presentation of the work with the children to the educational community and the implementation of a second survey about the knowledge of preventive measures towards educational experience. Results : In the sixth grade students , it was observed that 100 % of them brush their teeth, brushing frequency of 3 times a day increased 12 % and the toothbrush change was from 1 to 4 time a year . Cariogenic food intake decreased by 47 % and dental visits increased by 13%. Second grade students, 100% brush , brushing frequency was increased by 10 % for both 2 and 4 times a day. The non-cariogenic food intake was increased by 4% and dental visits increased by 13%. (α= 0.909) Conclusions: From the results obtained it could be concluded that the intervention of grandparents was positive in behavioral changes observed in children. http://www.dentalresearch.com publishedVersion Otras Ciencias de la Salud

Published
2013

27. Predictions for the Dirac CP violation phase in the neutrino mixing matrix.

Author

Petcov, S. T., Girardi, I., and Titov, A. V.

Subjects
*CP violation, *DIRAC function, *LEPTONS (Nuclear physics), *NEUTRINOS, *SUM rules (Physics), *NEUTRINO mass
Abstract

Using the fact that the neutrino mixing matrix , where Ue and Uν result from the diagonalization of the charged lepton and neutrino mass matrices, we analyze the predictions based on the sum rules which the Dirac phase δ present in U satisfies when Uν has a form dictated by, or associated with, discrete flavor symmetries and Ue has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to Uν, so that the reactor, atmospheric and solar neutrino mixing angles θ13, θ23 and θ12 have values compatible with the current data. [ABSTRACT FROM AUTHOR]

Published
2015
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28. The Daya Bay and T2K results on sin²2θ13 and non-standard neutrino interactions.

Author

Girardi, I., Meloni, D., and Petcov, S. T.

Subjects
*NEUTRINO interactions, *NONSTANDARD mathematical analysis, *CP violation, *OSCILLATIONS, *PROBABILITY theory, *PARAMETERS (Statistics)
Abstract

We show that the relatively large best fit value of sin²2θ13=0.14(0.17) measured in the T2K experiment for fixed values of i) the Dirac CP violation phase δ=0, and ii) the atmospheric neutrino mixing parameters θ23=π/4, |Δm32²|=2.4 x 10-3 eV², can be reconciled with the Daya Bay result sin²2θ13=0.090±0.009 if the effects of non-standard neutrino interactions (NSI) in the relevant ...e→...e and νμ→νe oscillation probabilities are taken into account. [ABSTRACT FROM AUTHOR]

Published
2014
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29. Non-Standard Neutrino Interactions in T2K and Daya Bay

Author

S. T. Petcov, Davide Meloni, I. Girardi, Paolo Bernardini, Gianluigi Fogli, Eligio Lisi, Girardi, I., Meloni, Davide, and Petcov, S. T.

Subjects
Physics, Nuclear and High Energy Physics, Sterile neutrino, Particle physics, Neutrino oscillation, non-standard neutrino interactions, Solar neutrino, T2K experiment, Dirac CP violation phase, Solar neutrino problem, neutrino mixing, Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici, Nuclear physics, neutrino mixing, non-standard neutrino interactions, Measurements of neutrino speed, CP violation, Neutrino, Non-standard neutrino interaction
Abstract

We show that the relatively large best fit value of sin 2 ⁡ 2 θ 13 = 0.14 ( 0.17 ) measured in the T2K experiment for fixed values of i) the Dirac CP violation phase δ = 0 , and ii) the atmospheric neutrino mixing parameters θ 23 = π / 4 , | Δ m 32 2 | = 2.4 × 10 − 3 eV 2 , can be reconciled with the Daya Bay result sin 2 ⁡ 2 θ 13 = 0.090 ± 0.009 if the effects of non-standard neutrino interactions (NSI) in the relevant ν ‾ e → ν ‾ e and ν μ → ν e oscillation probabilities are taken into account.

Published
2015

30. Probing new physics scenarios in accelerator and reactor neutrino experiments

Author

I. Girardi, Davide Meloni, A. Di Iura, Iura, A. Di, Girardi, I., and Meloni, Davide

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Sterile neutrino, Physics::Instrumentation and Detectors, Physics beyond the Standard Model, High Energy Physics::Phenomenology, FOS: Physical sciences, Parity (physics), large extra dimension, 7. Clean energy, Extra dimensions, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Mass spectrum, High Energy Physics::Experiment, Reactor neutrino, Neutrino mixing, Neutrino, Neutrino oscillation, non-standard interaction
Abstract

We perform a detailed combined fit to the $\overline \nu_e \rightarrow \overline \nu_e$ disappearence data of the Daya Bay experiment and the appearance $\nu_{\mu} \rightarrow \nu_{e}$ and disappearance $\nu_{\mu} \rightarrow \nu_{\mu}$ data of the Tokai to Kamioka (T2K) one in the presence of two models of new physics affecting neutrino oscillations, namely a model where sterile neutrinos can propagate in a large compactified extra dimension and a model where non-standard interactions (NSI) affect the neutrino production and detection. We find that the Daya Bay $\oplus$ T2K data combination constrains the largest radius of the compactified extra dimensions to be $R\lesssim 0.17$ $\mu {\rm m}$ at 2$\sigma$ C.L. (for the inverted ordering of the neutrino mass spectrum) and the relevant NSI parameters in the range ${\mathcal O}(10^{-3})-{\mathcal O}(10^{-2})$, for particular choices of the charged parity violating phases., Comment: 18 pages, 10 figures, 4 tables; typos corrected; matches published version

Published
2014

31. On the explainability of hospitalization prediction on a large COVID-19 patient dataset.

Author

Girardi I, Vagenas P, Arcos-D Iaz D, Bessa I L, Bu Sser A, Furlan L, Furlan R, Gatti M, Giovannini A, Hoeven E, and Marchiori C

Subjects
Cohort Studies, Hospitalization, Humans, Neural Networks, Computer, COVID-19 epidemiology
Abstract

We develop various AI models to predict hospitalization on a large (over 110k) cohort of COVID-19 positive-tested US patients, sourced from March 2020 to February 2021. Models range from Random Forest to Neural Network (NN) and Time Convolutional NN, where combination of the data modalities (tabular and time dependent) are performed at different stages (early vs. model fusion). Despite high data unbalance, the models reach average precision 0.96-0.98 (0.75-0.85), recall 0.96-0.98 (0.74-0.85), and F 1 -score 0.97-0.98 (0.79-0.83) on the non-hospitalized (or hospitalized) class. Performances do not significantly drop even when selected lists of features are removed to study model adaptability to different scenarios. However, a systematic study of the SHAP feature importance values for the developed models in the different scenarios shows a large variability across models and use cases. This calls for even more complete studies on several explainability methods before their adoption in high-stakes scenarios., (©2021 AMIA - All rights reserved.)

Published
2022

32. Artificial Intelligence Decision Support for Medical Triage.

Author

Marchiori C, Dykeman D, Girardi I, Ivankay A, Thandiackal K, Zusag M, Giovannini A, Karpati D, and Saenz H

Subjects
Algorithms, COVID-19 epidemiology, Decision Support Systems, Management, Expert Systems, Humans, SARS-CoV-2, Artificial Intelligence, COVID-19 prevention & control, Remote Consultation, Telemedicine, Triage
Abstract

Applying state-of-the-art machine learning and natural language processing on approximately one million of teleconsultation records, we developed a triage system, now certified and in use at the largest European telemedicine provider. The system evaluates care alternatives through interactions with patients via a mobile application. Reasoning on an initial set of provided symptoms, the triage application generates AI-powered, personalized questions to better characterize the problem and recommends the most appropriate point of care and time frame for a consultation. The underlying technology was developed to meet the needs for performance, transparency, user acceptance and ease of use, central aspects to the adoption of AI-based decision support systems. Providing such remote guidance at the beginning of the chain of care has significant potential for improving cost efficiency, patient experience and outcomes. Being remote, always available and highly scalable, this service is fundamental in high demand situations, such as the current COVID-19 outbreak., (©2020 AMIA - All rights reserved.)

Published
2021

33. Cognitive DDx Assistant in Rare Diseases.

Author

Reumann M, Giovannini A, Nadworny B, Auer C, Girardi I, and Marchiori C

Subjects
Diagnosis, Differential, Humans, Cognition, Rare Diseases
Abstract

There are between 6,000 - 7,000 known rare diseases today. Identifying and diagnosing a patient with rare disease is time consuming, cumbersome, cost intensive and requires resources generally available only at large hospital centers. Furthermore, most medical doctors, especially general practitioners, will likely only see one patient with a rare disease if at all. A cognitive assistant for differential diagnosis in rare disease will provide the knowledge on all rare diseases online, help create a list of weighted diagnosis and access to the evidence base on which the list was created. The system is built on knowledge graph technology that incorporates data from ICD-10, DOID, medDRA, PubMed, Wikipedia, Orphanet, the CDC and anonymized patient data. The final knowledge graph comprised over 500,000 nodes. The solution was tested with 101 published cases for rare disease. The learning system improves over training sprints and delivers 79.5 % accuracy in finding the diagnosis in the top 1 % of nodes. A further learning step was taken to rank the correct result in the TOP 15 hits. With a reduced data pool, 51% of the 101 cases were tested delivering the correct result in the TOP 3 - 13 (TOP 6 on average) for 74% of these cases. The results show that data curation is among the most critical aspects to deliver accurate results. The knowledge graph technology demonstrates its power to deliver cognitive solutions for differential diagnosis in rare disease that can be applied in clinical practice.

Published
2018
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34. CD14 expression in the first 24h of sepsis: effect of -260C>T CD14 SNP.

Author

de Aguiar BB, Girardi I, Paskulin DD, de Franca E, Dornelles C, Dias FS, Bonorino C, and Alho CS

Subjects
Adolescent, Adult, Aged, Aged, 80 and over, Cytokines metabolism, Female, Genetic Predisposition to Disease, Humans, Immunity, Innate genetics, Inflammation, Male, Middle Aged, Monocytes immunology, Monocytes metabolism, Polymorphism, Single Nucleotide, Prospective Studies, Sepsis metabolism, Sepsis mortality, Sepsis physiopathology, Survival Analysis, Time Factors, Lipopolysaccharide Receptors biosynthesis, Lipopolysaccharide Receptors genetics, Sepsis immunology
Abstract

Sepsis is defined as systemic inflammation caused by infection. The membrane bound CD14 (mCD14) or the soluble form (sCD14) play a crucial role facing Gram-negative and Gram-positive sepsis since they are pattern recognition receptors of the innate immune response enabling cells to produce inflammatory cytokines against bacterial infections. A -260C>T single nucleotide polymorphism (SNP) was detected in the promoter modulating the CD14 gene expression. We hypothesized that the CD14 expression depends of the genetic inheritance of -260C>T CD14 SNP and it is modulated by sepsis condition. We investigated human CD14 expression on early sepsis diagnosis (in vivo) and after LPS stimulation (in vitro), and determined the -260C>T CD14 SNP. We found that TT homozygotes showed higher mCD14 density (p = 0.0207), but not different sCD14 levels when compared to the CT+CC genotypes. Monocyte mCD14 density and sCD14 serum levels in our sample of early 14 septic patients were significantly higher than normal 30 controls (p<0.0001). Our results suggest that the -260TT CD14 genotype is associated with higher monocyte mCD14, but not sCD14 expression, and that in the first 24 h after sepsis diagnosis, both monocyte mCD14 density and sCD14 levels are elevated, similarly to what is observed in vitro upon challenge with LPS.

Published
2008
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