Exact SU(5) Yukawa matrix unification in the general flavour violating MSSM

Abstract

Abstract:We investigate the possibility of satisfying the SU(5) boundary condition Y d = Y e T at the GUT scale within the renormalizable R-parity conserving Minimal Supersymmetric Standard Model (MSSM). Working in the super-CKM basis, we consider non-zero flavour off-diagonal entries in the soft SUSY-breaking mass matrices and the Aterms. At the same time, the diagonal A-terms are assumed to be suppressed by the respective Yukawa couplings. We show that a non-trivial flavour structure of the soft SUSY-breaking sector can contribute to achieving precise Yukawa coupling unification for all three families, and that the relevant flavour-violating parameters are (m 2. We indicate the parameter space regions where the Yukawa unification condition can be satisfied, and we demonstrate that it is consistent with a wide set of experimental constraints, including flavour and electroweak observables, Higgs physics and the LHC bounds. However, as a consequence of the down-electron Yukawa unification requirement, the MSSM vacuum in our scenario is metastable, though long-lived. We also point out that the lightest neutralino needs to be almost purely bino-like and relatively light, with the mass in the ballpark of 250 GeV. Since the proper value of the dark matter relic density is in this case obtained through co-annihilation with a sneutrino, at least one generation of sleptons must be light. Such a clear experimental prediction makes the flavour-violating SU(5) Yukawa unification scenario fully testable at the LHC √ s = 14 TeV with the 3-lepton searches for electroweakino production.

Revisiting fermion mass and mixing fits in the minimal SUSY SO(10) GUT model

“…This inversely means that the present procedure in the SO(10) model (inputting the lepton parameters and outputting quark masses and mixings) provides a prediction to holomorphic Yukawa couplings for quarks at the unification scale, and the deviations from the observed values of quark masses can be buried by the threshold effects [42,43,44]. This feature can be applied to suppress the dimension-five operators in the SUSY GUT models.…”

“…We note that the charge/color breaking (CCB) vacua may appear for the large (1,1) element of the scalar trilinear coupling, and the electroweak symmetry breaking vacua may become metastable [45,46], similarly to the models in which the fermion masses and mixings are modified by the loop corrections [44]. Surely, if the lifetime of our vacuum can be larger than the age of the universe [47], the model is still valid.…”

Tasting the SU(5) nature of Supersymmetry at the LHC

“…Finally, let us note that for both low and high tan β, BR(τ → µγ) never exceeds the upper experimental value. Moreover, the value of the Higgs mass also does not strongly depend on the variation of (a u ) 23,32 or (a d ) 23,32 .…”

“…2, the main dependence of A 23 is with respect to the parameters (a u ) 23,32 and (a d ) 23,32 . We vary these parameters assuming that the SU (5) hypothesis is true, i.e.…”

“…We evaluate the asymmetry A 23 at the TeV scale for a scan in the parameters (a u ) 23 = (a u ) 32 s → µµ), ∆M Bs (see Fig. 1), and BR(b → sγ) (at high tan β, see Fig.…”