edoc: No conditions. Results ordered -Date Deposited. 2024-06-19T17:26:25ZEPrintshttps://edoc.unibas.ch/images/uni-logo.jpghttps://edoc.unibas.ch/2021-05-04T13:58:05Z2021-05-04T13:58:05Zhttps://edoc.unibas.ch/id/eprint/80046This item is in the repository with the URL: https://edoc.unibas.ch/id/eprint/800462021-05-04T13:58:05ZComparatively light extra Higgs states as signature of SUSY SO(10) GUTs with 3rd family Yukawa unificationWe study 3rd family Yukawa unification in the context of supersymmetric (SUSY) SO (10) GUTs and SO(10)-motivated boundary conditions for the SUSY-breaking soft terms. We consider mu < 0 such that the SUSY loop-threshold effects enable a good fit to all third family masses of the charged Standard Model (SM) fermions. We find that fitting the third family masses together with the mass of the SM-like Higgs particle, the scenario predicts the masses of the superpartner particles and of the extra Higgs states of the MSSM: while the sparticles are predicted to be comparatively heavy (above the present LHC bound but within reach of future colliders), the spectrum has the characteristic feature that the lightest new particles are the extra MSSM Higgses. We show that this effect is rather robust with respect to many deformations of the GUT boundary conditions, but turns out to be sensitive to the exactness of top-bottom Yukawa unification. Nevertheless, with moderate deviations of a few percent from exact top-bottom Yukawa unification (stemming e.g. from GUT-threshold corrections or higher-dimensional operators), the scenario still predicts extra MSSM Higgs particles with masses not much above 1.5 TeV, which could be tested e.g. by future LHC searches for ditau decays H-0/A(0)-> tau tau . Finding the extra MSSM Higges before the other new MSSM particles could thus be a smoking gun for a Yukawa unified SO(10) GUT. Stefan AntuschChristian HohlVasja Susivc2021-05-04T13:54:58Z2021-05-04T13:54:58Zhttps://edoc.unibas.ch/id/eprint/80045This item is in the repository with the URL: https://edoc.unibas.ch/id/eprint/800452021-05-04T13:54:58ZYukawa ratio predictions in non-renormalizable SO(10) GUT models
Since SO(10) GUTs unify all fermions of the Standard Model plus a right-chiral neutrino in a representation 16 per family, they have the potential to be maximally predictive regarding the ratios between the masses (or Yukawa couplings) of different fermion types, i.e. the up-type quarks, down-type quarks, charged leptons and neutrinos. We analyze the predictivity of classes of SO(10) (SUSY) GUT models for the fermion mass ratios, where the Yukawa couplings for each family are dominated by a single effective GUT operator of the schematic form 16(2) 45(n) 210(m) H, for H is an element of {10,120,126}. This extends previous works to general vacuum expectation value directions for GUT-scale VEVs and to larger Higgs representations. In addition, we show that the location of the MSSM Higgses in the space of all doublets is a crucial aspect to consider. We discuss highly predictive cases and illustrate the predictive power in toy models consisting of masses for the 3rd and 2nd fermion family. Stefan AntuschChristian HohlVasja Susivc2020-10-22T08:21:03Z2020-10-23T04:30:11Zhttps://edoc.unibas.ch/id/eprint/77949This item is in the repository with the URL: https://edoc.unibas.ch/id/eprint/779492020-10-22T08:21:03ZFlavour model building in the framework of Grand Unification and supergravityIn this thesis, we study new aspects of flavour model building in the context of supersymmetric Grand Unified Theories, where the focus lies on models with an SU(5) or SO(10) gauge group. In the framework of supergravity, we discuss how a typical flavon sector of a flavour model with spontaneously broken family symmetry can be combined with a SUSY breaking sector in a consistent manner. To demonstrate the predictive power of such an implementation, an example calculation for a flavour GUT model, which is based on an SU(5) gauge group, an A_4 family symmetry and a Z^R_4 R-symmetry, is performed. Assuming hidden sector SUSY breaking, we determine the structure of the soft SUSY breaking terms at the GUT scale and investigate the predictions for observables at low energy scales, such as the sparticle spectrum, the dark matter relic density and flavour violating processes. Next, we carry out a systematic analysis of a class of predictive SU(5) flavour GUT models with the CSD2 setup in the neutrino sector, and where the ratios of the Yukawa couplings in the down-quark and charged lepton sector are fixed by Clebsch-Gordan coefficients at the GUT scale, following the principle of single operator dominance. Alongside the identification of viable model candidates by performing a fit to experimental data for different combinations of CG coefficients, we calculate, among others, the predictions for the 2-3 mixing angle theta^PMNS_23 and the CP violating phase delta^PMNS in the lepton sector. In the context of SO(10) Grand Unification, a class of non-renormalizable Yukawa operators of the schematic form 16_I 16_J H 45^n 210^m is investigated, where H in {10,120,126bar} contains SU(2)_L doublet and antidoublet states, and 16_I,J the SM fermions. Moreover, the representations 45 and 210 acquire SM singlet vevs at the GUT scale. We provide general formulas to compute the resulting Yukawa couplings in the different fermion sectors of the MSSM, and discuss the construction of such operators from renormalizable interactions by using heavy mediators. In addition, we show that the alignment of the MSSM Higgs (anti)doublets H_u and H_d in the space of all SU(2)_L (anti)doublets of a concrete model is a central aspect for the prediction of Yukawa ratios at the GUT scale. Finally, we specify the numerical procedure to quantitatively calculate nucleon decay from dimension 5 operators in SUSY models, and apply the analysis to an example model with an SU(5) GUT symmetry. Christian Hohl2019-01-23T12:48:21Z2019-01-23T12:48:21Zhttps://edoc.unibas.ch/id/eprint/67255This item is in the repository with the URL: https://edoc.unibas.ch/id/eprint/672552019-01-23T12:48:21ZPredictions from a flavour GUT model combined with a SUSY breaking sectorStefan AntuschChristian Hohl