Related papers: MSSM with Large tan$\beta$ Constrained by Minimal …
We investigate the minimal Yukawa sector of grand unified theories based on $\mathrm{SO}(10)$ symmetry, consisting of a Higgs structure with representations $\mathbf{10}_{\mathbb{R}}\oplus \mathbf{120}_{\mathbb{R}}\oplus\mathbf{126}$. In…
We present a self-consistent $\chi^2$ analysis of several supersymmetric (SUSY) grand unified theories recently discussed in the literature. We obtain global fits to low energy data, including gauge couplings, fermion masses and mixing…
Simple supersymmetric grand unified models based on the gauge group SO(10) require --in addition to gauge and matter unification-- the unification of t-b-\tau Yukawa couplings. Yukawa unification, however, only occurs for very special…
Sufficient conditions for the relation $tan \beta \simeq m_t/m_b$ to hold in supersymmetric grand unified theories are formulated. Essential ingredients are the $SU(2)_R$ gauge symmetry and a discrete matter parity. The applicability of our…
The first fermion family might play a key role in understanding the structure of flavour: a role of the mass unification point. The GUT scale running masses $\bar{m}_{e,u,d}$ are rather close, which may indicate an approximate symmetry…
Third family Yukawa unification, as suggested by minimal SO(10) unification, is revisited in light of recent experimental measurements and theoretical progress. We characterize unification in a semi-model-independent fashion, and conclude…
We study low-energy consequences of supersymmetric $SO(10)$ models with Yukawa unification $h_t = h_N$ and $h_b = h_\tau$. We find that it is difficult to reproduce the observed $m_b/m_\tau$ ratio when the third-generation right-handed…
An analysis is given of the $b-\tau$ Yukawa coupling unification in view of the recent result from Brookhaven on $g_{\mu}-2$ and under the constraint of $b\to s+\gamma$. We explore $b-\tau$ unification under the above constraints for…
In various unified extensions of the Minimal Supersymmetric Standard Model, the Yukawa couplings of the third generation are predicted to be of the same order. As a result, low energy measured mass ratios, require large ratios of the…
Supersymmetric grand unified models based on the gauge group SU(5) often require in addition to gauge coupling unification, the unification of b-quark and $\tau$-lepton Yukawa couplings. We examine SU(5) SUSY GUT parameter space under the…
In grand unified theories (GUT) based on SO(10) all fermions of one generation are embedded in a single representation. As a result, the top quark, the bottom quark, and the $\tau$ lepton have a universal Yukawa coupling at the GUT scale.…
Combining the constraints coming from the ~$M_W$ ~measurements and the unsuccesful search for the Higgs boson at LEP we determine in the framework of MSSM the allowed mass regions for the lighter scalar partner of the top quark. For a heavy…
Within the framework of supersymmetric grand unification, estimates of the $b$ quark mass based on the asymptotic relation $m_b \simeq m_\tau$ single out the region with $\tan\beta$ close to unity, particularly if $m_t(m_t)…
We study the compatibility of a light bottom squark M_{\tilde b}< O(10 GeV) in the unconstrained MSSM. We consider the one-loop radiative corrections which are large for a heavy gluino (> O(150 GeV)). We then consider the renormalization…
Recent advances in the QCD corrections to $b\to s\gamma$ decay in the MSSM include i.) evaluation of the relevant operators, Wilson coefficients and anomalous dimension matrix elements for the various MSSM effective theories valid at scales…
We construct a supersymmetric SO(10) model with the asymptotic relation tan$\beta \simeq m_t/m_b$ automatically arising from its structure. The model retains the significant Minimal Supersymmetric Standard Model predictions for $sin^2…
The status of top-bottom-tau Yukawa coupling unification in supersymmetric SO(10) models is reviewed with a particular emphasis on the implications of the Higgs boson mass in the vicinity of 125 GeV, as suggested by the LHC Higgs data. In…
We construct a supersymmetric model based on the semi-simple gauge group $SU(3)_c \times SU(3)_L \times SU(3)_R$ with the relation $tan\beta \simeq m_t/m_b$ automatically arising from its structure. The model below a scale $\sim 10^{16}$…
We study B_s-\bar{B}_s mixing in grand unified SO(10), SU(5) models where the mixings among the second and third generation squarks arise due to the existence of flavor violating sources in the Dirac and Majorana couplings which are…
In the light of the gathering evidence for $\nu_{\mu}-\nu_{\tau}$ neutrino oscillations, coming in particular from the Super-Kamiokande data on atmospheric neutrinos, we re-analyze the unification of gauge and Yukawa couplings within the…