Home << 1 2 3 4 5 >>
List View
 | 
Citations
 | 
Details
   web
Records
Author Emmanuel-Costa, D.; Simoes, C.; Tortola, M.
Title The minimal adjoint-SU (5) x Z(4) GUT model Type Journal Article
Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue (up) 10 Pages 054 - 30pp
Keywords Neutrino Physics; GUT; Discrete and Finite Symmetries
Abstract An extension of the adjoint SU (5) model with a flavour symmetry based on the Z(4) group is investigated. The Z(4) symmetry is introduced with the aim of leading the up-and down-quark mass matrices to the Nearest-Neighbour-Interaction form. As a consequence of the discrete symmetry embedded in the SU (5) gauge group, the charged lepton mass matrix also gets the same form. Within this model, light neutrinos get their masses through type-I, type-III and one-loop radiative seesaw mechanisms, implemented, respectively, via a singlet, a triplet and an octet from the adjoint fermionic 24 fields. It is demonstrated that the neutrino phenomenology forces the introduction of at least three 24 fermionic multiplets. The symmetry SU (5) x Z(4) allows only two viable zero textures for the effective neutrino mass matrix. It is showed that one texture is only compatible with normal hierarchy and the other with inverted hierarchy in the light neutrino mass spectrum. Finally, it is also demonstrated that Z(4) freezes out the possibility of proton decay through exchange of coloured Higgs triplets at tree-level.
Address [Emmanuel-Costa, D.; Simoes, C.] Univ Lisbon, Inst Super Tecn, Dept Fis, P-1049001 Lisbon, Portugal, Email: david.costa@ist.utl.pt;
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:000325495200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1604
Permanent link to this record
 
 
Author Bernabeu, J.; Di Domenico, A.; Villanueva-Perez, P.
Title Probing CPT in transitions with entangled neutral kaons Type Journal Article
Year 2015 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue (up) 10 Pages 139 - 19pp
Keywords Discrete and Finite Symmetries; Kaon Physics; CP violation
Abstract In this paper we present a novel CPT symmetry test in the neutral kaon system based, for the first time, on the direct comparison of the probabilities of a transition and its CPT reverse. The required interchange of in <-> out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a phi-factory. The observable quantities have been constructed by selecting the two semileptonic decays for flavour tag, the pi and 3 pi(0) decays for CP tag and the time orderings of the decay pairs. The interpretation in terms of the standard Weisskopf-Wigner approach to this system, directly connects CPT violation in these observables to the violating R delta parameter in the mass matrix of K-0 – (K) over bar (0), a genuine CPT violating effect independent of Delta Gamma and not requiring the decay as an essential ingredient. Possible spurious effects induced by CP violation in the decay and/or a violation of the Delta S = Delta Q rule have been shown to be well under control. The proposed test is thus fully robust, and might shed light on possible new CPT violating mechanisms, or further improve the precision of the present experimental limits. It could be implemented at the DA Phi NE facility in Frascati, where the KLOE-2 experiment might reach a statistical sensitivity of O (10(-3)) on the newly proposed observable quantities.
Address [Bernabeu, J.; Villanueva-Perez, P.] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: jose.bernabeu@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:000363478100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2420
Permanent link to this record
 
 
Author Centelles Chulia, S.; Cepedello, R.; Medina, O.
Title Absolute neutrino mass scale and dark matter stability from flavour symmetry Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue (up) 10 Pages 080 - 23pp
Keywords Discrete Symmetries; Flavour Symmetries; Neutrino Mixing; Particle Nature of Dark Matter
Abstract We explore a simple but extremely predictive extension of the scotogenic model. We promote the scotogenic symmetry Z(2) to the flavour non-Abelian symmetry sigma(81), which can also automatically protect dark matter stability. In addition, sigma(81) leads to striking predictions in the lepton sector: only Inverted Ordering is realised, the absolute neutrino mass scale is predicted to be m(lightest)approximate to 7.5x10(-4) eV and the Majorana phases are correlated in such a way that vertical bar m(ee)vertical bar approximate to 0.018 eV. The model also leads to a strong correlation between the solar mixing angle theta(12) and delta(CP), which may be falsified by the next generation of neutrino oscillation experiments. The setup is minimal in the sense that no additional symmetries or flavons are required.
Address [Chulia, Salvador Centelles] Max Planck Inst Kernphys, Saupfercheckweg 1, D-69117 Heidelberg, Germany, Email: chulia@mpi-hd.mpg.de;
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:000867661300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5387
Permanent link to this record
 
 
Author de Medeiros Varzielas, I.; King, S.F.; Luhn, C.; Neder, T.
Title Spontaneous CP violation in multi-Higgs potentials with triplets of Delta(3n(2)) and Delta(6n(2)) Type Journal Article
Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue (up) 11 Pages 136 - 56pp
Keywords CP violation; Discrete Symmetries; Higgs Physics; Beyond Standard Model
Abstract Motivated by discrete flavour symmetry models, we analyse Spontaneous CP Violation (SCPV) for potentials involving three or six Higgs fi elds (both electroweak doublets and singlets) which fall into irreducible triplet representations of discrete symmetries belonging to the Delta(3n(2)) and Delta(6n(2)) series, including A(4), S-4, Delta(27) and Delta(54). For each case, we give the potential and fi nd various global minima for di ff erent regions of the parameter space of the potential. Using CP-odd basis Invariants that indicate the presence of Spontaneous CP Violation we separate the VEVs into those that do or do not violate CP. In cases where CP is preserved we reveal a CP symmetry of the potential that is preserved by those VEVs, otherwise we display a non-zero CP-odd Invariant. Finally we identify interesting cases where there is Spontaneous Geometrical CP Violation in which the VEVs have geometrical phases.
Address [Varzielas, Ivo de Medeiros; King, Stephen F.; Neder, Thomas] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England, Email: ivo.de@udo.edu;
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:000416354700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3383
Permanent link to this record
 
 
Author Bernabeu, J.; Segarra, A.
Title Signatures of the genuine and matter-induced components of the CP violation asymmetry in neutrino oscillations Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue (up) 11 Pages 063 - 26pp
Keywords CP violation; Discrete Symmetries; Neutrino Physics
Abstract CP asymmetries for neutrino oscillations in matter can be disentangled into the matter-induced CPT-odd (T-invariant) component and the genuine T-odd (CPT-invariant) component. For their understanding in terms of the relevant ingredients, we develop a new perturbative expansion in both m2| without any assumptions between m2 and a, and study the subtleties of the vacuum limit in the two terms of the CP asymmetry, moving from the CPT-invariant vacuum limit a 0 to the T-invariant limit m20. In the experimental region of terrestrial accelerator neutrinos, we calculate their approximate expressions from which we prove that, at medium baselines, the CPT-odd component is small and nearly -independent, so it can be subtracted from the experimental CP asymmetry as a theoretical background, provided the hierarchy is known. At long baselines, on the other hand, we find that (i) a Hierarchy-odd term in the CPT-odd component dominates the CP asymmetry for energies above the first oscillation node, and (ii) the CPT-odd term vanishes, independent of the CP phase , at E = 0.92 GeV (L/1300 km) near the second oscillation maximum, where the T-odd term is almost maximal and proportional to sin . A measurement of the CP asymmetry in these energy regions would thus provide separate information on (i) the neutrino mass ordering, and (ii) direct evidence of genuine CP violation in the lepton sector.
Address [Bernabeu, Jose] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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:000449817300002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3801
Permanent link to this record
 
 
Author Celis, A.; Fuentes-Martin, J.; Serodio, H.
Title A class of invisible axion models with FCNCs at tree level Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue (up) 12 Pages 167 - 53pp
Keywords Beyond Standard Model; CP violation; Global Symmetries
Abstract We build a class of invisible axion models with tree-level Flavor Changing Neutral Currents completely controlled by the fermion mixing matrices. The scalar sector of these models contains three-Higgs doublets and a complex scalar gauge singlet, with the same fermionic content as in the Standard Model. A horizontal Peccei-Quinn symmetry provides a solution to the strong CP problem and predicts the existence of a very light and weakly coupled pseudo-Goldstone boson, the invisible axion or familon. A phenomenological analysis is performed taking into account familon searches in rare kaon and muon decays, astrophysical considerations and axion searches via axion-photon conversion. Drastic differences are found in the axion properties of different models due to the strong hierarchy of the CKM matrix, making some of the models considered much more constrained than others. We also obtain that a rich variety of these models avoid the domain wall problem. A possible mechanism to protect the solution to the strong CP problem against gravitational effects is also discussed.
Address [Celis, Alejandro; Fuentes-Martin, Javier] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: alejandro.celis@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:000347160000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2067
Permanent link to this record
 
 
Author Drewes, M.; Georis, Y.; Hagedorn, C.; Klaric, J.
Title Low-scale leptogenesis with flavour and CP symmetries Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue (up) 12 Pages 044 - 113pp
Keywords Baryo-and Leptogenesis; Discrete Symmetries; Flavour Symmetries; Sterile or Heavy Neutrinos
Abstract We consider a type-I seesaw framework endowed with a flavour symmetry, belonging to the series of non-abelian groups increment (3 n(2)) and increment (6 n(2)), and a CP symmetry. Breaking these symmetries in a non-trivial way results in the right-handed neutrinos being degenerate in mass up to possible (further symmetry-breaking) splittings kappa and lambda, while the neutrino Yukawa coupling matrix encodes the entire flavour structure in the neutrino sector. For a fixed combination of flavour and CP symmetry and residual groups, this matrix contains five real free parameters. Four of them are determined by the light neutrino mass spectrum and by accommodating experimental data on lepton mixing well, while the angle theta(R) is related to right-handed neutrinos. We scrutinise for all four lepton mixing patterns, grouped into Case 1) through Case 3 b.1), the potential to generate the baryon asymmetry of the Universe through low-scale leptogenesis numerically and analytically. The main results are: a) the possible correlation of the baryon asymmetry and the Majorana phases, encoded in the Pontecorvo-Maki-Nakagawa-Sakata mixing matrix, in certain instances; b) the possibility to generate the correct amount of baryon asymmetry for vanishing splittings kappa and lambda among the right-handed neutrinos as well as for large kappa, depending on the case and the specific choice of group theory parameters; c) the chance to produce sufficient baryon asymmetry for large active-sterile mixing angles, enabling direct experimental tests at current and future facilities, if theta(R) is close to a special value, potentially protected by an enhanced residual symmetry. We elucidate these results with representative examples of flavour and CP symmetries, which all lead to a good agreement with the measured values of the lepton mixing angles and, possibly, the current indication of the CP phase delta. We identify the CP-violating combinations relevant for low-scale leptogenesis, and show that the parametric dependence of the baryon asymmetry found in the numerical study can be understood well with their help.
Address [Drewes, M.; Georis, Y.; Klaric, J.] Catholic Univ Louvain, Ctr Cosmol Particle Phys & Phenomenol, B-1348 Louvain La Neuve, Belgium, Email: marco.drewes@uclouvain.be;
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:000898830800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5435
Permanent link to this record
 
 
Author Lavoura, L.; Morisi, S.; Valle, J.W.F.
Title Accidental stability of dark matter Type Journal Article
Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue (up) 2 Pages 118 - 17pp
Keywords Beyond Standard Model; Neutrino Physics; Discrete and Finite Symmetries
Abstract We propose that dark matter is stable as a consequence of an accidental Z(2) that results from a flavour symmetry group which is the double-cover group of the symmetry group of one of the regular geometric solids. Although model-dependent, the phenomenology resembles that of a generic “inert Higgs” dark matter scheme.
Address [Lavoura, L.] Univ Tecn Lisboa, CFTP, Inst Super Tecn, P-1049001 Lisbon, Portugal, Email: balio@cftp.ist.utl.pt;
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000316273700041 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1383
Permanent link to this record
 
 
Author Bernabeu, J.; Segarra, A.
Title Stimulated transitions in resonant atom Majorana mixing Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue (up) 2 Pages 017 - 16pp
Keywords Neutrino Physics; Beyond Standard Model; Global Symmetries
Abstract Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual Delta L = 2 mixing between a parent (A)Z atom and a daughter (A)(Z – 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant 'stationary" states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration.
Address [Bernabeu, Jose] Univ Valencia, CSIC, Dept Fis Teor, Calle Dr Moliner 50, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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:000424101600008 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3475
Permanent link to this record
 
 
Author Carcamo Hernandez, A.E.; Kovalenko, S.; Valle, J.W.F.; Vaquera-Araujo, C.A.
Title Neutrino predictions from a left-right symmetric flavored extension of the standard model Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue (up) 2 Pages 065 - 24pp
Keywords Beyond Standard Model; Discrete Symmetries; Neutrino Physics; Quark Masses and SM Parameters
Abstract We propose a left-right symmetric electroweak extension of the Standard Model based on the Delta (27) family symmetry. The masses of all electrically charged Standard Model fermions lighter than the top quark are induced by a Universal Seesaw mechanism mediated by exotic fermions. The top quark is the only Standard Model fermion to get mass directly from a tree level renormalizable Yukawa interaction, while neutrinos are unique in that they get calculable radiative masses through a low-scale seesaw mechanism. The scheme has generalized μ- tau symmetry and leads to a restricted range of neutrino oscillations parameters, with a nonzero neutrinoless double beta decay amplitude lying at the upper ranges generically associated to normal and inverted neutrino mass ordering.
Address [Carcamo Hernandez, A. E.; Kovalenko, Sergey] Univ Tecn Federico Santa Maria, Casilla 110-5, Valparaiso, Chile, Email: antonio.carcamo@usm.cl;
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:000459168900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3917
Permanent link to this record