Ilia Gogoladze

Higgs boson mass, sparticle spectrum, and the little hierarchy problem in an extended MSSM

We investigate the impact of TeV-scale matter belonging to complete vectorlike multiplets of unified groups on the lightest Higgs boson in the MSSM. We find that consistent with perturbative unification and electroweak precision data the mass m{sub h} can be as large as 160 GeV. These extended MSSM models can also render the little hierarchy problem less severe, but only for lower values of m{sub h} < or approx. 125) GeV. We present estimates for the sparticle mass spectrum in these models.

Interpretation of the diphoton excess at CMS and ATLAS

We consider the diphoton resonance at the 13 TeV LHC in a consistent model with new scalars and vector-like fermions added to the Standard Model, which can be constructed from orbifold grand unified theories and string models. The gauge coupling unification can be achieved, neutrino masses can be generated radiatively, and the electroweak vacuum stability problem can be solved. To explain the diphoton resonance, we study a spin-0 particle, and discuss various associated final states. We also constrain the couplings and number of the introduced heavy multiplets for the new resonances width at 5 or 40 GeV.

Precision electroweak constraints on universal extra dimensions revisited

We reconsider the constraints on universal extra dimensions models arising from precision electroweak data. We take into account the subleading contributions from new physics (expressed in terms of the

Higgs boson mass from t-b-τ Yukawa unification

X,Y,\dots{}

Revisiting mGMSB in Light of a 125 GeV Higgs

variables), as well as two-loop corrections to the standard model

NONUNIVERSAL GAUGINO MASSES AND NATURAL SUPERSYMMETRY

\ensuremath{\rho}

Higgs boson mass bounds in a type II seesaw model with triplet scalars

parameter. For the case of one extra dimension, we obtain a lower bound on the inverse compactification scale

Yukawa Unification and Neutralino Dark Matter in SU(4)(c) x SU(2)(L) x SU(2)(R)

M={R}^{\ensuremath{-}1}

Nonuniversal gaugino masses and muong-2

of 600 GeV (at 90% confidence level), with a Higgs mass of 115 GeV. However, in contradiction to recent claims, we find that this constraint is significantly relaxed with increasing Higgs mass, allowing for compactification scales as low as 300 GeV. LEP II data does not affect significantly these results.

NMSSM and Seesaw Physics at LHC

A bstractWe employ the Yukawa coupling unification condition, yt = yb = yτ at MGUT, inspired by supersymmetric SO(10) models, to estimate the lightest Higgs boson mass as well as masses of the associated squarks and gluino. We employ non-universal soft masses, dictated by SO(10) symmetry, for the gauginos. Furthermore, the soft masses for the two scalar Higgs doublets are set equal at MGUT, and in some examples these are equal to the soft masses for scalars in the matter multiplets. For μ > 0, M2  > 0, where M2 denotes the SU(2) gaugino mass, essentially perfect t-b-τ Yukawa unification is possible, and it predicts a Higgs mass of 122-124 GeV with a theoretical uncertainty of about ±3 GeV. The corresponding gluino and the first two family squarks have masses ≳ 3 TeV. We present some LHC testable benchmark points which also show the presence of neutralino-stau coannihilation in this scenario. The well-known MSSM parameter tan β ≈ 47.