Related papers: Low energy Yukawa input parameters for Yukawa coup…
In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling $y_t$ should not exceed the critical value $y_t^{crit}$, coinciding with good precision (about 0.02%) with the…
The Gr\"uneisen parameter is evaluated for three-dimensional Yukawa systems in the strongly coupled regime. Simple analytical expression is derived from the thermodynamic consideration and its structure is analysed in detail. Possible…
The wave functions and Yukawa couplings of the top and bottom quarks in the SO(5) x U(1) gauge-Higgs unification model are determined. The result is summarized in the effective interactions for \hat \theta_H(x) = \theta_H + H(x)/f_H where…
Group theoretical factors from GUT symmetry breaking can lead to predictions for the ratios of quark and lepton masses (or Yukawa couplings) at the unification scale. Due to supersymmetric (SUSY) threshold corrections the viability of such…
In this paper, we present a formalism for computing the Yukawa couplings in heterotic standard models. This is accomplished by calculating the relevant triple products of cohomology groups, leading to terms proportional to Q*H*u, Q*Hbar*d,…
How accurately should the top quark mass be measured in order to test theoretical predictions? A possible answer is presented within a particular theoretical framework, that of top-bottom-tau Yukawa unification in a supersymmetric SO(10)…
Heavy squark decays into top and charginos or neutralinos could be an unexpected source of top quarks at hadron colliders. A detailed treatment of these processes is necessary for a reliable calculation of both the top quark production…
We propose a flavour structure for the leptonic sector of the Standard Model, based on the idea of universality of Yukawa couplings, which accommodates all the experimental data on neutrino masses and mixing, at the same time predicting…
We investigate the Yukawa sector for up-like quarks in the Lee's version of the Littlest Higgs model. We derive general quark mass and mixing formulae and study leading order contributions due to non-zero light quark masses. Relying on the…
We give examples of minimal extensions of the simplest SU(5) SUSY-GUT in which all squarks and sleptons of a family have different tree level masses at the unification scale. This phenomenon is general; it occurs when the quarks and leptons…
In simple SO(10) SUSY GUTs the top, bottom and tau Yukawa couplings unify at the GUT scale. A naive renormalization group analysis, neglecting weak scale threshold corrections, leads to moderate agreement with the low energy data. However…
The calculation of Yukawa couplings in F-theory GUTs is developed. The method is applied to the top and bottom Yukawa couplings in an SU(5) model of fermion masses based on family symmetries coming from the SU(5)_\perp factor in the…
Running quark mass values $m_q(\mu)$ at some typical energy scales ($\mu=1$ GeV, $\mu=m_W$, and so on) are reviewed. The values depend considerably on the value of $\Lambda_{\overline{MS}}$, especially, the value of top quark mass at…
Predictions for the total cross section for e+e- -> t tbar near threshold are reviewed. The renormalization group improved results at NNLL order have improved convergence and reduced scale dependence relative to fixed order results at NNLO.…
We explore the low energy implications of an F-theory inspired $E_6$ model whose breaking yields, in addition to the MSSM gauge symmetry, a $Z'$ gauge boson associated with a $U(1)$ symmetry broken at the TeV scale. The zero mode spectrum…
A quark mass matrix model $M_q=M_e^{1/2} O_q M_e^{1/2} $ is proposed where $M_e^{1/2}={\rm diag}(\sqrt{m_e},\sqrt{m_\mu},\sqrt{m_\tau})$ and $O_q$ is a unit matrix plus a rank one matrix. Up- and down-quark mass matrices $M_u$ and $M_d$ are…
We present analytic expressions for the top and bottom Yukawa couplings in the context of the minimal supersymmetric standard model when both couplings $h_{t,0},h_{b,0}$ are large at the unification scale. For sufficiently large…
The phenomenology of a low-energy supersymmetry at hadron colliders is discussed with consideration of the minimal supergravity model, with a large top quark Yukawa coupling at the grand unification mass scale, and gauge mediated symmetry…
The energy levels of neutral atoms supported by Yukawa potential, $V(r)=-Z exp(-\alpha r)/r$, are studied, using both dimensional and dimensionless quantities, via a new analytical methodical proposal (devised to solve for nonexactly…
We discuss the possibility of unifying in a simple and economical manner the Yukawa couplings of third generation fermions in a non-supersymmetric SO(10) model with an intermediate symmetry breaking, focusing on two possible patterns with…