Seminarium Teorii Oddziaływań Elementarnych

The simplest Grand Unified Theory (GUT) embedding the Standard Model (SM)is based on the SU(5) symmetry. The unification of gauge couplings,failing in the SM, takes place in the widely studied R-parity conservingMinimal Supersymmetric Standard Model (MSSM). The possibility ofsatisfying the minimal SU(5) boundary conditions also for Yukawa matricesat the GUT scale within the MSSM is investigated and a new region in theparameter space consistent with this requirement is identified. The equality of down-quark and lepton Yukawa matrices at the GUT scale canbe achieved with non-zero flavour off-diagonal entries in the softSUSY-breaking mass matrices and the A-terms. The proposed scenario isconsistent with a wide set of experimental constraints, including flavourand electroweak observables, Higgs physics and the LHC bounds. Moreover, for all points with unified Yukawas, the lightest neutralino isalmost pure bino and relatively light, ~250 GeV. The proper value of thedark matter relic density can then be achieved only with at least onegeneration of light sleptons present. This prediction makes theflavour-violating SU(5) Yukawa unification scenario fully testable at theLHC 14 TeV with the 3-lepton searches for electroweakino production.