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Author Alcaide, J.; Salvado, J.; Santamaria, A.
Title Fitting flavour symmetries: the case of two-zero neutrino mass textures Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages (up) 164 - 18pp
Keywords Neutrino Physics; Quark Masses and SM Parameters
Abstract We present a numeric method for the analysis of the fermion mass matrices predicted in flavour models. The method does not require any previous algebraic work, it offers a chi(2) comparison test and an easy estimate of confidence intervals. It can also be used to study the stability of the results when the predictions are disturbed by small perturbations. We have applied the method to the case of two-zero neutrino mass textures using the latest available fits on neutrino oscillations, derived the available parameter space for each texture and compared them. Textures A(1) and A(2) seem favoured because they give a small chi(2), allow for large regions in parameter space and give neutrino masses compatible with Cosmology limits. The other “allowed” textures remain allowed although with a very constrained parameter space, which, in some cases, could be in conflict with Cosmology. We have also revisited the “forbidden” textures and studied the stability of the results when the texture zeroes are not exact. Most of the forbidden textures remain forbidden, but textures F-1 and F-3 are particularly sensitive to small perturbations and could become allowed.
Address [Alcaide, Julien; Santamaria, Arcadi] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Valencia, Spain, Email: julien.alcaide@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:000440091700010 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3680
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Author De Romeri, V.; Fernandez-Martinez, E.; Gehrlein, J.; Machado, P.A.N.; Niro, V.
Title Dark Matter and the elusive Z' in a dynamical Inverse Seesaw scenario Type Journal Article
Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages (up) 169 - 21pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract The Inverse Seesaw naturally explains the smallness of neutrino masses via an approximate B-L symmetry broken only by a correspondingly small parameter. In this work the possible dynamical generation of the Inverse Seesaw neutrino mass mechanism from the spontaneous breaking of a gauged U(1) B-L symmetry is investigated. Interestingly, the Inverse Seesaw pattern requires a chiral content such that anomaly cancellation predicts the existence of extra fermions belonging to a dark sector with large, non-trivial, charges under the U(1) B-L. We investigate the phenomenology associated to these new states and find that one of them is a viable dark matter candidate with mass around the TeV scale, whose interaction with the Standard Model is mediated by the Z' boson associated to the gauged U(1) B-L symmetry. Given the large charges required for anomaly cancellation in the dark sector, the B-L Z' interacts preferentially with this dark sector rather than with the Standard Model. This suppresses the rate at direct detection searches and thus alleviates the constraints on Z'-mediated dark matter relic abundance. The collider phenomenology of this elusive Z' is also discussed.
Address [De Romeri, Valentina] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Calle Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: deromeri@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:000414811300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3357
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Author Abada, A.; De Romeri, V.; Lucente, M.; Teixeira, A.M.; Toma, T.
Title Effective Majorana mass matrix from tau and pseudoscalar meson lepton number violating decays Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages (up) 169 - 57pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract An observation of any lepton number violating process will undoubtedly point towards the existence of new physics and indirectly to the clear Majorana nature of the exchanged fermion. In this work, we explore the potential of a minimal extension of the Standard Model via heavy sterile fermions with masses in the [0.1-10] GeV range concerning an extensive array of “neutrinoless” meson and tau decay processes. We assume that the Majorana neutrinos are produced on-shell, and focus on three-body decays. We conduct an update on the bounds on the active-sterile mixing elements, vertical bar U-l alpha 4,U-l beta 4 vertical bar, taking into account the most recent experimental bounds (and constraints) and new theoretical inputs, as well as the effects of a finite detector, imposing that the heavy neutrino decay within the detector. This allows to establish up-to-date comprehensive constraints on the sterile fermion parameter space. Our results suggest that the branching fractions of several decays are close to current sensitivities (likely within reach of future facilities), some being already in conflict with current data (as is the case of K-broken vertical bar -> l(alpha)(broken vertical bar)+l(beta)(+)pi(-), and tau(-)->mu(broken vertical bar)pi(-)pi(-)). We use these processes to extract constraints on all entries of an enlarged definition of a 3 x 3 “effective” Majorana neutrino mass matrix m(v)(alpha beta).
Address [Abada, Asmaa] Univ Paris Saclay, Univ Paris Sud, CNRS, Lab Phys Theor, 15 Rue Georges Clemenceau, F-91405 Orsay, France, Email: abada@th.u-psud.fr;
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:000426478100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3511
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Author Masud, M.; Mehta, P.; Ternes, C.A.; Tortola, M.
Title Non-standard neutrino oscillations: perspective from unitarity triangles Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages (up) 171 - 19pp
Keywords Beyond Standard Model; CP violation; Neutrino Physics
Abstract We formulate an alternative approach based on unitarity triangles to describe neutrino oscillations in presence of non-standard interactions (NSI). Using perturbation theory, we derive the expression for the oscillation probability in case of NSI and cast it in terms of the three independent parameters of the leptonic unitarity triangle (LUT). The form invariance of the probability expression (even in presence of new physics scenario as long as the mixing matrix is unitary) facilitates a neat geometric view of neutrino oscillations in terms of LUT. We examine the regime of validity of perturbative expansions in the NSI case and make comparisons with approximate expressions existing in literature. We uncover some interesting dependencies on NSI terms while studying the evolution of LUT parameters and the Jarlskog invariant. Interestingly, the geometric approach based on LUT allows us to express the oscillation probabilities for a given pair of neutrino flavours in terms of only three (and not four) degrees of freedom which are related to the geometric properties (sides and angles) of the triangle. Moreover, the LUT parameters are invariant under rephasing transformations and independent of the parameterization adopted.
Address [Masud, Mehedi] Inst Basic Sci IBS, Ctr Theoret Phys Universe, Daejeon 34126, South Korea, Email: masud@ibs.re.kr;
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:000658364000005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4864
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Author Barducci, D.; Bertuzzo, E.; Caputo, A.; Hernandez, P.
Title Minimal flavor violation in the see-saw portal Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages (up) 185 - 28pp
Keywords Neutrino Physics; Beyond Standard Model; CP violation
Abstract We consider an extension of the Standard Model with two singlet leptons, with masses in the electroweak range, that induce neutrino masses via the see-saw mechanism, plus a generic new physics sector at a higher scale, A. We apply the minimal flavor violation (MFV) principle to the corresponding Effective Field Theory (nu SMEFT) valid at energy scales E << A. We identify the irreducible sources of lepton flavor and lepton number violation at the renormalizable level, and apply the MFV ansatz to derive the scaling of the Wilson coefficients of the nu SMEFT operators up to dimension six. We highlight the most important phenomenological consequences of this hypothesis in the rates for exotic Higgs decays, the decay length of the heavy neutrinos, and their production modes at present and future colliders. We also comment on possible astrophysical implications.
Address [Barducci, Daniele] Univ Roma La Sapienza, Dipartimento Fis, Piazzale Aldo Moro 5, I-00185 Rome, Italy, Email: daniele.barducci@roma1.infn.it;
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:000546965800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4462
Permanent link to this record