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Author (up) Casas, J.A.; Moreno, J.M.; Rius, N.; Ruiz de Austri, R.; Zaldivar, B.
Title Fair scans of the seesaw. Consequences for predictions on LFV processes Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 034 - 22pp
Keywords Neutrino Physics; Supersymmetric Standard Model
Abstract We give a straightforward procedure to scan the seesaw parameter-space, using the common “R-parametrization”, in a complete way. This includes a very simple rule to incorporate the perturbativity requirement as a condition for the entries of the R-matrix. As a relevant application, we show that the somewhat propagated belief that BR(mu -> e, gamma) in supersymmetric seesaw models depends strongly on the value of theta(13) is an “optical effect” produced by incomplete scans, and does not hold after a careful analytical and numerical study. When the complete scan is done, BR(mu -> e, gamma) gets very insensitive to theta(13). This holds even if the right-handed neutrino masses are kept constant or under control (as is required for succesful leptogenesis). In most cases the values of BR(mu -> e, gamma) are larger than the experimental upper bound. Including (unflavoured) leptogenesis does not introduce any further dependence on theta(13), although decreases the typical value of BR(mu -> e, gamma).
Address [Alberto Casas, J.; Moreno, Jesus M.; Zaldivar, Bryam] UAM, IFT UAM CSIC, Inst Fis Teor, Madrid 28049, Spain, Email: alberto.casas@uam.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 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000289295200034 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 612
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Author (up) Centelles Chulia, S.; Cepedello, R.; Peinado, E.; Srivastava, R.
Title Systematic classification of two-loop d=4 Dirac neutrino mass models and the Diracness-dark matter stability connection Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 093 - 33pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We provide a complete systematic classification of all two-loop realizations of the dimension four operator for Dirac neutrino masses. Our classification is multi-layered, starting first with a classification in terms of all possible distinct two loop topologies. Then we discuss the possible diagrams for each topology. Model-diagrams originating from each diagram are then considered. The criterion for genuineness is also defined and discussed at length. Finally, as examples, we construct two explicit models which also serve to highlight the intimate connection between the Dirac nature of neutrinos and the stability of dark matter.
Address [Chulia, Salvador Centelles; Cepedello, Ricardo; Srivastava, Rahul] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cient Paterna,C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: salcen@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:000491092500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4181
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Author (up) Centelles Chulia, S.; Srivastava, R.; Vicente, A.
Title The inverse seesaw family: Dirac and Majorana Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 248 - 29pp
Keywords Beyond Standard Model; Neutrino Physics; Global Symmetries
Abstract After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking “mu -parameters”. These models can be tested both in colliders and with the observation of lepton flavour violating processes.
Address [Centelles Chulia, Salvador; Vicente, Avelino] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cientif Paterna,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: salcen@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:000635241800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4772
Permanent link to this record
 

 
Author (up) Cepedello, R.; Fonseca, R.M.; Hirsch, M.
Title Systematic classification of three-loop realizations of the Weinberg operator Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 197 - 34pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We study systematically the decomposition of the Weinberg operator at three-loop order. There are more than four thousand connected topologies. However, the vast majority of these are infinite corrections to lower order neutrino mass diagrams and only a very small percentage yields models for which the three-loop diagrams are the leading order contribution to the neutrino mass matrix. We identify 73 topologies that can lead to genuine three-loop models with fermions and scalars, i.e. models for which lower order diagrams are automatically absent without the need to invoke additional symmetries. The 73 genuine topologies can be divided into two sub-classes: normal genuine ones (44 cases) and special genuine topologies (29 cases). The latter are a special class of topologies, which can lead to genuine diagrams only for very specific choices of fields. The genuine topologies generate 374 diagrams in the weak basis, which can be reduced to only 30 distinct diagrams in the mass eigenstate basis. We also discuss how all the mass eigenstate diagrams can be described in terms of only five master integrals. We present some concrete models and for two of them we give numerical estimates for the typical size of neutrino masses they generate. Our results can be readily applied to construct other d = 5 neutrino mass models with three loops.
Address [Cepedello, Ricardo; Hirsch, Martin] Univ Valencia, CSIC, AHEP Grp, Inst Fis Corpuscular, Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: ricepe@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:000449260800013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3792
Permanent link to this record
 

 
Author (up) Cepedello, R.; Hirsch, M.; Helo, J.C.
Title Lepton number violating phenomenology of d=7 neutrino mass models Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 009 - 24pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We study the phenomenology of d = 7 1-loop neutrino mass models. All models in this particular class require the existence of several new SU(2)(L) multiplets, both scalar and fermionic, and thus predict a rich phenomenology at the LHC. The observed neutrino masses and mixings can easily be fitted in these models. Interestingly, despite the smallness of the observed neutrino masses, some particular lepton number violating (LNV) final states can arise with observable branching ratios. These LNV final states consists of leptons and gauge bosons with high multiplicities, such as 4/ + 4W, 6/ + 2W etc. We study current constraints on these models from upper bounds on charged lepton flavour violating decays, existing lepton number conserving searches at the LHC and discuss possible future LNV searches.
Address [Cepedello, R.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: ricepe@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:000419113900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3443
Permanent link to this record