Probing Leptonic Models at the LHC

Models of neutrino mass generation provide well motivated scenarios of Beyond-the-Standard-Model physics. The synergy between low energy and high energy LHC searches facilitates an effective approach to rule out, constrain or ideally pinpoint such models. In this proceedings report, we provide a brief overview of scenarios where searches at the LHC can help determine the mechanism of light neutrino masses and potentially falsify baryogenesis mechanisms.Comment: Talk presented at CIPANP2015. 9 pages, 3 figure

Thermal Right-Handed Sneutrino Dark Matter in the F_D-Term Model of Hybrid Inflation

We compute the relic abundance of the right-handed sneutrinos in the supersymmetric F_D-term model of hybrid inflation. As well as providing a natural solution to the mu- and gravitino overabundance problems, the F_D-term model offers a new viable candidate to account for the cold dark matter in the Universe: the lightest right-handed sneutrino. In particular, the F_D-term model predicts a new quartic coupling of purely right-handed sneutrinos to the Higgs doublets that thermalizes the sneutrinos and makes them annihilate sufficiently fast to a level compatible with the current cosmic microwave background data. We analyze this scenario in detail and identify favourable regions of the parameter space within the framework of minimal supergravity, for which the lightest right-handed sneutrino becomes the thermal dark matter, in agreement with WMAP observations of cosmological inflation. Constraints derived from direct dark matter searches experiments are presented.Comment: 26 pages, 4 eps figures, version published in JHE

Dark Matter and Lepton Flavour Violation in a Hybrid Neutrino Mass Model

We describe a hybrid model in which the light neutrino mass matrix receives both tree-level seesaw and loop-induced contributions. An additional U(1) gauge symmetry is used to stabilize the lightest right-handed neutrino as the Dark Matter candidate. After fitting the experimental neutrino data, we analyze and correlate the phenomenological consequences of the model, namely its impact on electroweak precision measurements, the Dark Matter relic abundance, lepton flavour violating rare decays and neutrinoless double beta decay. We find that natural realizations of the model characterized by large Yukawa couplings are compatible with and close to the current experimental limits.Comment: 25 pages, 9 figures. V2: references added, typos corrected, version accepted by JHE

Lepton Flavour Violation and theta(13) in Minimal Resonant Leptogenesis

We study the impact of minimal non-supersymmetric models of resonant leptogenesis on charged lepton flavour violation and the neutrino mixing angle theta(13). Possible low-scale flavour realisations of resonant tau-, mu- and e-leptogenesis provide very distinct and predictive frameworks to explain the observed baryon asymmetry in the Universe by sphaleron conversion of an individual tau-, mu- and e-lepton-number asymmetry which gets resonantly enhanced via out-of-equilibrium decays of nearly degenerate heavy Majorana neutrinos. Based on approximate flavour symmetries, we construct viable scenarios of resonant tau-, mu- and e-leptogenesis compatible with universal right-handed neutrino masses at the GUT scale, where the required heavy-neutrino mass splittings are generated radiatively. The heavy Majorana neutrinos in such scenarios can be as light as 100 GeV and their couplings to two of the charged leptons may be large. In particular, we explicitly demonstrate the compelling role that the three heavy Majorana neutrinos play, in order to obtain successful leptogenesis and experimentally testable rates for lepton flavour violating processes, such as mu --> e gamma and mu --> e conversion in nuclei.Comment: 40 pages, 9 figures, PRD versio

Minimal Resonant Leptogenesis and Lepton Flavour Violation

We discuss minimal non-supersymmetric models of resonant leptogenesis, based on an approximate flavour symmetries. As an illustrative example, we consider a resonant tau-leptogenesis model, compatible with universal right-handed neutrino masses at the GUT scale, where the required heavy-neutrino mass splittings are generated radiatively. In particular, we explicitly demonstrate, how a minimum number of three heavy Majorana neutrinos is needed, in order to obtain successful leptogenesis and experimentally testable rates for processes of lepton flavour violation, such as mu --> e gamma and mu --> e conversion in nuclei.Comment: 7 pages, invited talk given by AP at the international conference GUT2012, Kyoto, Japan, 15-17 March 201

Confronting SUSY SO(10) with updated Lattice and Neutrino Data

We present an updated fit of supersymmetric SO(10) models to quark and lepton masses and mixing parameters. Including latest results from lattice QCD determinations of quark masses and neutrino oscillation data, we show that fits neglecting supersymmetric threshold corrections are strongly disfavoured in our setup. Only when we include these corrections we find good fit points. We present $\chi^2$-profiles for the threshold parameters, which show that in our setup the thresholds related to the third generation of fermions exhibit two rather narrow minima.Comment: 23 pages, 3 figures, and 5 tables; version published in JHE

Constraints on SUSY Seesaw from Leptogenesis and LFV

We study constraints on the fundamental parameters of supersymmetric type I seesaw models imposed by neutrino data, charged lepton flavor violation, thermal leptogenesis and perturbativity of the neutrino Yukawa couplings.Comment: 4 pages, 2 figures, to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 200