Related papers: F-theory, GUTs, and the Weak Scale
Consider a gauge singlet superfield S coupled to a pair of adjoint fields in a SUSY-GUT. If the tree-level vacuum is flat in S, the vev <S> which defines the GUT scale will be determined via dimensional transmutation at a scale M where the…
A constraint on masses of superheavy gauge and Higgs multiplets at the grand unification (GUT) scale is obtained from the gauge coupling unification in the case of high-scale supersymmetry. We found that all of the particles may lie around…
Evidence is mounting that natural supersymmetry at the weak scale is not realized in nature. On the other hand, string theory suggests that supersymmetry may be present at some energy scale, and gauge coupling unification implies that that…
We propose to generate non-universal gaugino masses in SU(5) GUT with the generalized Planck-scale mediation SUSY breaking mechanism, in which the non-universality arises from proper wavefunction normalization with lowest component VEVs of…
We consider the minimal supersymmetric Standard Model with large scalar and gaugino mass terms at the GUT scale, which are generated predominantly by gauge-mediated supersymmetry breaking. For certain ratios of GUT-scale masses, determined…
We examine some conditions which are needed to allow the Peccei-Quinn scale (f_a) as high as the SUSY GUT scale (M_{GUT} \sim 10^{16} GeV) in the context of the PQMSSM with either an axino or a neutralino LSP. The main problem in non-SUSY…
We study phenomenological aspects of supersymmetric SU(5) grand unified theories with non-universal gaugino masses. For large tan beta, we investigate constraints from the requirement of successful electroweak symmetry breaking, the…
In the generalized minimal supergravity (GmSUGRA) scenario, we systematically study the supersymmetry breaking scalar masses, Standard Model fermion Yukawa coupling terms, and trilinear soft terms in SU(5) models with the Higgs fields in…
We perform a detailed study of the grand unified theories $SO(10)$ and $E(6)$ with left-right intermediate gauge symmetries of the form $SU(N)_L\otimes SU(N)_R \otimes \mathcal{G}$. Proton decay lifetime constrains the unification scale to…
We study phenomenological aspects of supersymmetric SO(10) GUTs with sum rules among soft SUSY breaking parameters. In particular, the sum rule related to the stau mass leads to the constraints from the requirements of successful…
Relations between the gaugino masses have been shown to alleviate the degree of fine-tuning in the MSSM. In this paper we consider specific models of supersymmetry breaking with gravity mediation and demonstrate that within both GUT and…
In order to significantly reduce the fine-tuning associated with the electroweak symmetry breaking in the minimal supersymmetric standard model (MSSM), we consider not only the minimal gravity mediation effects but also the minimal gauge…
Motivated by the recently measured muon's anomalous magnetic moment $a_{\mu}$, we examine the supersymmetry contribution to $a_{\mu}$ in various mediation models of supersymmetry breaking which lead to predictive flavor conserving soft…
We consider the possibility that the soft supersymmetry-breaking parameters m_{1/2} and m_0 of the MSSM are universal at some scale M_{in} below the supersymmetric grand unification scale M_{GUT}, as might occur in scenarios where either…
High-scale supersymmetry (SUSY) with a split spectrum has become increasingly interesting given the current experimental results. A SUSY scale above the weak scale could be naturally associated with a heavy unstable gravitino, whose decays…
Supersymmetry and supergravity extend the standard model by introducing a new symmetry between fermions and bosons. Experimental data imply that supergravity must be broken. Among several mechanisms of supersymmetry breaking, gravity…
We study gaugino-mediated supersymmetry breaking in a six-dimensional SO(10) orbifold GUT model where quarks and leptons are mixtures of brane and bulk fields. The couplings of bulk matter fields to the supersymmetry breaking brane field…
We derive in detail a condition on the Higgs mass parameters that is necessary for the recently proposed ``split supersymmetry'' (split SUSY) scenario to provide a realistic magnitude of $\tan \beta$. The nature of this condition can be…
The recent measurement of a_\mu =\frac{g_\mu -2}{2} by the E821 Collaboration at Brookhaven deviates from the quoted Standard Model (SM) central value prediction by 2.6\sigma. The difference between SM theory and experiment may be easily…
We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model…