It is well-known that in scenarios with direct gauge mediation of supersymmetry breaking the messenger fields significantly affect the running of Standard Model couplings and introduce Landau poles which are difficult to avoid. This appears to remove any possibility of a meaningful unification prediction and is often viewed as a strong argument against direct mediation. We propose two ways that Seiberg duality can circumvent this problem. In the first, which we call "deflected-unification", the SUSY-breaking hidden sector is a magnetic theory which undergoes a duality to an electric phase, with fewer elementary degrees of freedom coupled to the MSSM. This changes the beta-functions of the MSSM gauge couplings so as to push their Landau poles above the unification scale. We show that this scenario is realised for recently suggested models of gauge mediation based on a metastable SCQD-type hidden sector directly coupled to MSSM. The second possibility, which we call "dual-unification", begins with the observation that, if the mediating fields fall into complete SU(5) multiplets, then the MSSM+messengers exhibits a fake unification at unphysical values of the gauge couplings. We show that, in known examples of electric/magnetic duals, such a fake unification in the magnetic theory reflects a real unification in the electric theory. We therefore propose that the Standard Model could itself be a magnetic dual of some unknown electric theory in which the true unification takes place. This scenario maintains the unification prediction (and unification scale) even in the presence of Landau poles in the magnetic theory below the GUT scale. We further note that this dual realization of grand unification can explain why Nature appears to unify, but the proton does not decay.
We investigate the building of models with Dirac gauginos and perturbative gauge coupling unification. Here, in contrast to the MSSM, additional fields are required for unification, and these can naturally play the role of the messengers of supersymmetry breaking. We present a framework within which such models can be constructed, including the constraints that the messenger sector must satisfy; and the renormalisation group equations for the soft parameters, which differ from those of the MSSM. For illustration, we provide the spectrum at the electroweak scale for explicit models whose gauge …
We discuss the proton lifetime in pure gravity mediation models with non-universal Higgs soft masses. Pure gravity mediation offers a simple framework for studying SU(5) grand unified theories with a split supersymmetry like spectra. We find that for much of the parameter space gauge coupling unification is quite good leading to rather long lifetimes for the proton. However, for $m_{3/2}\sim 60$ TeV and $\tanβ\sim 4$, for which gauge coupling unification is also good, the proton lifetime is short enough that it could be in reach of future experiments.
In certain models of gauge-mediated supersymmetry breaking with messenger fields in incomplete GUT multiplets, the radiative corrections to the Higgs potential cancel out during renormalization group running. This allows for relatively heavy superpartners and for a 125 GeV Higgs while the fine-tuning remains modest. In this paper, we show that such gauge mediation models with "focus point" behaviour can be naturally embedded into a model of SU(5) x U(3) product group unification.
In this letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the GUT scale, which we characterize as effective "mirage" mediation. We perform a global chi-squared analysis including the observables M_W, M_Z, G_F, alpha_em, alpha_s(M_Z), M_top, m_b(m_b), M_tau, BR(B -> X_s gamma), BR(B_s -> mu^+ mu^-) and M_{h}. The fit is performed in the MSSM in terms of 10 GUT scale parameters, while tanb and mu are fixed at the weak scale. We find good fits to the low energy data and a SUSY spectrum whi…
The requirement of Yukawa coupling unification highly constrains the SUSY parameter space. In several SUSY breaking scenarios it is hard to reconcile Yukawa coupling unification with experimental constraints from B(b->s gamma) and the muon anomalous magnetic moment a_mu. We show that b-tau or even t-b-tau Yukawa unification can be satisfied simultaneously with b->s gamma and a_mu in the non-universal gaugino mediation scenario. Non-universal gaugino masses naturally appear in higher dimensional grand unified models in which gauge symmetry is broken by orbifold compactification. Relations betwe…
We explore the implications of t-b-tau (and b-tau) Yukawa coupling unification condition on the fundamental parameter space and sparticle spectroscopy in the minimal gauge mediated supersymmetry breaking (mGMSB) model. We find that this scenario prefers values of the CP-odd Higgs mass m_A > 1 TeV, with all colored sparticle masses above 3 TeV. These predictions will be hard to test at LHC13 but they may be testable at HE-LHC 33 TeV or a 100 TeV collider. Both t-b-tau and b-tau Yukawa coupling unifications prefer a relatively light gravitino with mass < 30 eV, which makes it a candidate hot dar…
In General Gauge Mediation (GGM) all MSSM soft sfermion masses at a high scale M_mess can be parameterised by three a priori independent scales Λ_{S;1,2,3}(M_mess). (Similarly the gaugino masses are given by Λ_{G;1,2,3}(M_mess).) For the first two generations this parameterisation in terms of a set of running Λ_{S;1,2,3}(μ) -- conveniently obtained from appropriate RG invariants -- continues to hold all the way down to the electroweak scale. This is not the case for the third generation because of the large Yukawa couplings. Together these two observations imply that the messenger scale is an …
We study the Yukawa unification, in particular, the unification of the Yukawa coupling constants of $b$ and $τ$, in the framework of supersymmetric (SUSY) model. We concentrate on the model in which the SUSY breaking scalar masses are of the order of the gravitino mass while the gaugino masses originate from the effect of anomaly mediation and hence are one-loop suppressed relative to the gravitino mass. We perform an accurate calculation of the Yukawa coupling constants of $b$ and $τ$ at the grand unified theory (GUT) scale, including relevant renormalization group effects and threshold corre…
We build explicit supersymmetric unification models where grand unified gauge symmetry breaking and supersymmetry (SUSY) breaking are caused by the same sector. Besides, the SM-charged particles are also predicted by the symmetry breaking sector, and they give the soft SUSY breaking terms through the so-called gauge mediation. We investigate the mass spectrums in an explicit model with SU(5) and additional gauge groups, and discuss its phenomenological aspects. Especially, nonzero A-term and B-term are generated at one-loop level according to the mediation via the vector superfields, so that t…
We propose a focus point gauge mediation model based on the product group unification (PGU), which solves the doublet-triplet splitting problem of the Higgs multiplets. In the focus point gauge mediation, the electroweak symmetry breaking scale can be naturally explained even for multi-TeV stops. It is known that the focus point behavior appears if a ratio of the number of SU(2) doublet messengers to that of SU(3) triplet messengers is close to 5/2. Importantly, this ratio (effectively) appears in our scenario based on the PGU, if the messenger field is an adjoint representation of SU(5) gauge…
Grand-unified models with extra dimensions at the GUT scale will typically contain exotic states with Standard Model charges and GUT-scale masses. They can act as messengers for gauge-mediated supersymmetry breaking. If the number of messengers is sizeable, soft terms for the visible sector fields will be predominantly generated by gauge mediation, while gravity mediation can induce a small mu parameter. We illustrate this hybrid mediation pattern with two examples, in which the superpartner spectrum contains light and near-degenerate higgsinos with masses below 200 GeV. The typical masses of …
Under the assumption that all the gauge groups in supersymmetric theories unify at the fundamental scale, the numbers and the mass scales of messenger quarks and leptons, as well as the beta-function coefficient of the sector for dynamical supersymmetry breaking are constrained depending on various gauge mediation mechanisms. For this, we use one-loop renormalization group equations and draw constraints on the scales in each gauge mediation model.
We study a new class of scenarios with the gaugino mass unification at the weak scale. The general condition is first derived for the unification to occur. Among the general cases, a particular attention is drawn to the mirage gauge mediation where the low-energy mass spectrum is governed by the mirage of unified gauge coupling which is seen by low-energy observers. The gaugino masses have natural and stable low-scale unification. The mass parameters of scalar quarks and leptons are given by gauge couplings but exhibit no large mass hierarchy. They are non-universal even when mediated at the g…
The lack of evidence for low-scale supersymmetry suggests that the scale of supersymmetry breaking may be higher than originally anticipated. However, there remain many motivations for supersymmetry including gauge coupling unification and a stable dark matter candidate. Models like pure gravity mediation (PGM) evade LHC searches while still providing a good dark matter candidate and gauge coupling unification. Here, we study the effects of PGM if the input boundary conditions for soft supersymmetry breaking masses are pushed beyond the unification scale and higher dimensional operators are in…
We propose a new class of models with gauge mediated supersymmetry breaking, the cascade supersymmetry breaking. This class of models is consistent with the gravitino mass as low as O(1)eV without having suppressed gaugino masses, nor the Landau pole problems of the gauge coupling constants of the Standard Model below the scale of the grand unification. In particular, there is no supersymmetric vacuum in the vicinity of the supersymmetry breaking vacuum even for such a low gravitino mass. Thus, the model does not have a vacuum stability problem decaying into supersymmetric vacua.
As the mass limits on supersymmetric particles are gradually pushed to higher values due to their continuing non-observation at the CERN LHC, looking for focus point regions in the supersymmetric parameter space, which shows considerably reduced fine-tuning, is increasingly more important than ever. We explore this in the context of gauge mediated supersymmetry breaking with messengers transforming in the adjoint representation of the gauge group, namely, octet of color SU(3) and triplet of weak SU(2). A distinctive feature of this scenario is that the focus point is achieved by fixing a singl…
We review recent works on supersymmetry breaking and gauge mediation. We survey our current understanding of dynamical supersymmetry breaking mechanisms and describe new model building tools using duality, meta-stability, and stringy construction. We discuss phenomenological constraints and their solutions, paying attentions to issues with gaugino masses and electroweak symmetry breaking.
We study dark matter for gaugino-mediated supersymmetry breaking and compact dimensions of order the grand unification scale. Higgs fields are bulk fields, and in general their masses differ from those of squarks and sleptons at the unification scale. As a consequence, at different points in parameter space, the gravitino, a neutralino or a scalar lepton can be the lightest (LSP) or next-to-lightest (NLSP) superparticle. We investigate the constraints from primordial nucleosynthesis on the different scenarios. While neutralino and gravitino dark matter with a sneutrino NLSP are consistent for …
We consider states in the adjoint representation of the Standard Model gauge group as messengers for mediation of supersymmetry (SUSY) breaking. These new messengers can shift the gauge coupling unification to the string scale at O(5x10^{17} GeV) if their masses are at O(10^{14} GeV). The predicted SUSY mass spectrum at the electroweak scale is significantly different from those in other gauge-mediated or supergravity models, resulting in robust mass relations. The gravitino mass is predicted to be about 1-10 GeV. The heavy messenger sector could provide a superheavy dark matter candidate.
We study gauge mediation of supersymmetry breaking in SU(5) supersymmetric grand unified theory with gauge fields as messengers. The generated soft supersymmetry breaking parameters lead to close to maximal mixing scenario for the Higgs mass and highly reduce the fine tuning of electroweak symmetry breaking. All gaugino, squark and slepton masses are determined by one parameter -- the supersymmetry breaking scale. The characteristic features are: negative and non-universal squark and slepton masses squared at the unification scale, non-universal gaugino masses, and sizable soft-trilinear coupl…
We present a general phenomenological framework for dialing between gravity mediation, gauge mediation, and anomaly mediation. The approach is motivated from recent developments in moduli stabilization, which suggest that gravity mediated terms can be effectively loop suppressed and thus comparable to gauge and anomaly mediated terms. The gauginos exhibit a mirage unification behavior at a "deflected" scale, and gluinos are often the lightest colored sparticles. The approach provides a rich setting in which to explore generalized supersymmetry breaking at the LHC.
A slice of AdS_5 is used to provide a 5D gravitational description of 4D strongly-coupled Seiberg dual gauge theories. An (electric) SU(N) gauge theory in the conformal window at large N is described by the 5D bulk, while its weakly coupled (magnetic) dual is confined to the IR brane. This framework can be used to construct an N = 1 MSSM on the IR brane, reminiscent of the original Randall-Sundrum model. In addition, we use our framework to study strongly-coupled scenarios of supersymmetry breaking mediated by gauge forces. This leads to a unified scenario that connects the extra-ordinary gaug…
We present a model of supersymmetry breaking in which the contributions from gravity/modulus, anomaly, and gauge mediation are all comparable. We term this scenario "deflected mirage mediation," which is a generalization of the KKLT-motivated mirage mediation scenario to include gauge mediated contributions. These contributions deflect the gaugino mass unification scale and alter the pattern of soft parameters at low energies. In some cases, this results in a gluino LSP and light stops; in other regions of parameter space, the LSP can be a well-tempered neutralino. We demonstrate explicitly th…
We present a simple model of gauge mediation (GM) which does not have a messenger sector or gauge singlet fields. The standard model gauge groups couple directly to the sector which breaks supersymmetry dynamically. This is the first phenomenologically viable example of this type in the literature. Despite the direct coupling, the model can preserve perturbative gauge unification. This is achieved by the inverted hierarchy mechanism which generates a large scalar expectation value compared to the size of supersymmetry breaking. There is no dangerous negative contribution to the squark, slepton…
String compactification with fluxes yields MSSM soft SUSY breaking terms that receive comparable contributions from modulus and anomaly mediation whose relative strength is governed by a phenomenological parameter $α$. Gaugino and first/second generation (and sometimes also Higgs and third generation) scalar mass parameters unify at a mirage unification scale $Q \not= M_{\rm GUT}$, determined by the value of $α$. The ratio of scalar to gaugino masses at this mirage unification scale depends directly on the scalar field modular weights, which are fixed in turn by the brane or brane intersection…
We analyze an R-symmetry breaking deformation of the ISS model for a direct mediation of supersymmetry breaking from a metastable vacuum. The model is weakly coupled and calculable. The LSP gravitino is light (m_{3/2}<16 eV) and the MSSM spectrum is natural with a light Higgs. The supersymmetry breaking sector, which is usually hidden, is observable (m~1 TeV) and may be a candidate for cold dark matter. We discuss its production and signature at LHC. We propose a UV completion of the model in terms of a duality cascade.
We revisit the implications of naturalness and gauge unification in the MSSM. We find that precision unification of the couplings in connection with a small mu parameter requires a highly compressed gaugino pattern as it is realized in mirage mediation. Due to the small mass difference between gluino and LSP, collider limits on the gluino mass are drastically relaxed. Without further assumptions, the relic density of the LSP is very close to the observed dark matter density due to coannihilation effects.
We derive explicitly the soft SUSY breaking parameters at arbitrary low energy scale in the (deflected) mirage type mediation scenarios with possible gauge or Yukawa mediation contributions. Based on the Wilsonian effective action after integrating out the messengers, we obtain analytically the boundary value (at the GUT scale) dependencies of the effective wavefunctions and gauge kinetic terms. Note that the messenger scale dependencies of the effective wavefunctions and gauge kinetic terms had already been discussed in GMSB. The RGE boundary value dependencies, which is a special feature in …
We present a new, simple supersymmetry breaking model with direct gauge mediation. Supersymmetry breaking sector is based on the model with an Affine quantum moduli space. The model has no gauge messengers and no light scalars charged under the Standard Model which give a negative contribution to the soft masses. Large expectation value at the minimum is obtained by balancing the runaway potential and the dimension six nonrenormalizable term. This makes it easy to preserve the perturbative unification. Enough suppression of the supergravity contribution to the soft masses can also be shown.
We describe renormalizable supersymmetric four-dimensional theories which lead to gaugino mediation and various generalizations thereof. Even though these models are strongly coupled, we can demonstrate the parametric suppression of soft scalar masses via Seiberg duality. For instance, we show that our models have a parameter which continuously interpolates between suppressed soft scalar masses and their conventional gauge mediated contribution. The main physical effect which we utilize is the general relation between massive deformations in one frame and higgsing in the dual frame. Some compe…
We consider a relative of semi-direct gauge mediation where the hidden sector exists at large 't Hooft coupling. Such scenarios can be difficult to describe using perturbative field theory methods but may fall into the class of holographic gauge mediation scenarios, meaning that they are amenable to the techniques of gauge/gravity duality. We use a recently found gravity solution to examine one such case where the hidden sector is a cascading gauge theory resulting in a confinement scale not much smaller than the messenger mass. In the original construction of holographic gauge mediation, as i…
We consider a class of $b-τ$ Yukawa unified Supersymmetric (SUSY) $SU(5)$ GUTs, in which the asymptotic gaugino $M_{1,2,3}$ masses are generated through a combination of gravity and mirage mediated supersymmetry breaking. Due to the contributions from mirage mediation, $M_{3}$ is always lighter than M_{1} and M_{2}, and consequently for the range of asymptotic masses considered, the gluino mass at low scale is bounded from above at about 4 TeV. We realize two different regions, one in which the MSSM $μ-$term is less than about 3 TeV. This region yields a stop mass up to 5 TeV, and the stop mas…
We undertake a phenomenological study of SU(5) F-theory GUT models with an additional U(1)_{PQ} symmetry. In such models, breaking SU(5) with hypercharge flux leads to the presence of non-GUT multiplets in the spectrum. We study the effect these have on the unification of gauge couplings, including two-loop running as well as low- and high-scale threshold corrections. We use the requirement of unification to constrain the size of thresholds from KK modes of SU(5) gauge and matter fields. Assuming the non-GUT multiplets play the role of messengers of gauge mediation leads to controlled non-univ…
In the context of anomaly-mediated supersymmetry breaking, it is natural for vectorlike fields and singlets to have supersymmetry breaking masses of order 10 TeV, and therefore act as messengers of supersymmetry breaking. We show that this can give rise to phenomenologically viable spectra compatible with perturbative gauge coupling unification. The minimal model interpolates continuously between pure anomaly mediation and gauge mediation with a messenger scale of order 10 TeV. It is also possible to have non-minimal models with more degenerate specta, with some squarks lighter than sleptons. …
It has been recently proposed to embed the standard model in a conformal gauge theory to resolve the hierarchy problem, and to avoid assuming either grand unification or low-energy supersymmetry. By model building based on string-field duality we show how to maintain the successful prediction of an electroweak mixing angle with $sin^2θ\simeq 0.231$ in conformal gauge theories with three chiral families.
We study constraints on the general gauge mediation (GGM) parameter space arising from low-energy observables in the MSSM and NMSSM. Specifically, we look at the dependence of the spectra and observables on the correlation function ratios in the hidden sector where supersymmetry is presumably broken. Since these ratios are not a priori constrained by theory, current results from the muon anomalous magnetic moment and flavor physics can potentially provide valuable intuition about allowed possibilities. It is found that the muon anomalous magnetic moment and flavor-physics observables place sig…
We consider the situation in which $m_{3/2}\sim O(100{\rm TeV})$ for solving the gravitino problem and the other supersymmetry(SUSY) breaking parameters are $O(1{\rm TeV})$ for the naturalness. We point out that the anomaly mediation cancels out the renormalization group contribution to the gaugino masses and the sfermion masses other than the stop masses at a scale which is called the mirage scale. The situation is similar to the mirage mediation, in which special boundary conditions for the SUSY breaking parameters are required, though for the stop masses and the up-type Higgs mass, such can…
We discuss gauge mediated supersymmetry breaking models which explain the observed muon anomalous magnetic moment and the Higgs boson mass simultaneously. The successful explanation requires the messenger sector which violates the relation motivated by the grand unification theory (GUT). The naive violation of the GUT relation, however, ends up with the CP problem. We propose a model in which the phases of the gaugino masses are aligned despite the violation of the GUT relation. We also consider a model which generates the $μ$-term and the additional Higgs soft masses squared without causing C…
It has been recently pointed out that the unavoidable tuning among supersymmetric parameters required to raise the Higgs boson mass beyond its experimental limit opens up new avenues for dealing with the so called $μ$-$B_μ$ problem of gauge mediation. In fact, it allows for accommodating, with no further parameter tuning, large values of $B_μ$ and of the other Higgs-sector soft masses, as predicted in models where both $μ$ and $B_μ$ are generated at one-loop order. This class of models, called Lopsided Gauge Mediation, offers an interesting alternative to conventional gauge mediation and is ch…
Anomaly mediated supersymmetry breaking (AMSB), when implemented in MSSM is known to suffer from the problem of negative slepton mass squared leading to breakdown of electric charge conservation. We show however that when MSSM is extended to explain small neutrino masses by including a pair of superheavy Higgs triplet superfields (the type II seesaw mechanism), the slepton masses can be deflected from the pure AMSB trajectory and become positive. In a simple model we present in this paper, the seesaw scale is about $10^{13}-10^{14}{\rm GeV}$. Gauge coupling unification can be maintained by emb…
We explore gauge coupling unification and dark matter in high scale supersymmetry where the scale of supersymmetry breaking is much above the weak scale. The gauge couplings unify as precisely as in low energy supersymmetry if the higgsinos, whose mass does not break supersymmetry, are much lighter than those obtaining masses from supersymmetry breaking. The dark matter of the universe can then be explained by the neutral higgsino or the gravitino. High scale supersymmetry with light higgsinos requires a large Higgs mixing parameter for electroweak symmetry breaking to take place. It is thus n…
Motivated by the simple toroidal compactification of extra-dimensional SUSY theories, we investigate on a partially $N=2$ supersymmetric (SUSY) extension of the standard model which has an $N=2$ SUSY sector and an $N=1$ SUSY sector. We point out that below the scale of the partially breaking of $N=2$ to $N=1$, the ratio of Yukawa to gauge couplings embedded in the original $N=2$ gauge interaction in the $N=2$ sector becomes greater due to a fixed point. Since at the partially breaking scale the sfermion masses in the $N=2$ sector is suppressed due to the $N=2$ non-renormalization theorem, the …
The sweet spot supersymmetry (SUSY) solves the mu problem in the Minimal Supersymmetric Standard Model (MSSM) with gauge mediated SUSY breaking (GMSB) via the generalized Giudice-Masiero (GM) mechanism where only the mu-term and soft Higgs masses are generated at the unification scale of the Grand Unified Theory (GUT) due to the approximate PQ symmetry. Because all the other SUSY breaking soft terms are generated via the GMSB below the GUT scale, there exists SUSY electroweak (EW) fine-tuning problem to explain the 125 GeV Higgs boson mass due to small trilinear soft term. Thus, to explain the…
We show that gauge-mediation and unified-supergravity give sufficiently firm and different predictions for the spectrum of supersymmetric particles to make it possible to discriminate the two scenarios even if the messenger mass is close to the unification scale.
A complete 5-dimensional SU(5) unified theory is constructed which, on compactification on the orbifold with two different Z_2's (Z_2 and Z_2'), yields the minimal supersymmetric standard model. The orbifold accomplishes SU(5) gauge symmetry breaking, doublet-triplet splitting, and a vanishing of proton decay from operators of dimension 5. Until 4d supersymmetry is broken, all proton decay from dimension 4 and dimension 5 operators is forced to vanish by an exact U(1)_R symmetry. Quarks and leptons and their Yukawa interactions are located at the Z_2 orbifold fixed points, where SU(5) is unbro…
We propose the SUSY SU(7) unification of the SU(3)_C* SU(4)_W* U(1)_{B-L} model. Such unification scenario has rich symmetry breaking chains in a five-dimensional orbifold. We study in detail the SUSY SU(7) symmetry breaking into SU(3)_C* SU(4)_W* U(1)_{B-L} by boundary conditions in a Randall-Sundrum background and its AdS/CFT interpretation. We find that successful gauge coupling unification can be achieved in our scenario. Gauge unification favors low left-right and unification scales with tree-level \sin^2θ_W=0.15. We use the AdS/CFT dual of the conformal supersymmetry breaking scenario to…
If supersymmetry (SUSY) solves the hierarchy problem, then naturalness considerations coupled with recent LHC bounds require non-trivial superpartner flavor structures. Such "Natural SUSY" models exhibit a large mass hierarchy between scalars of the third and first two generations as well as degeneracy (or alignment) among the first two generations. In this work, we show how this specific beyond the standard model (SM) flavor structure can be tied directly to SM flavor via "Flavor Mediation". The SM contains an anomaly-free SU(3) flavor symmetry, broken only by Yukawa couplings. By gauging thi…
Using two-loop renormalization group equations implementing the decoupling of heavy scalars, Effective SUSY scenarios are studied in the limit in which there is a single low energy Higgs field. Gauge coupling unification is shown to hold with similar or better precision than in standard MSSM scenarios. b-tau unification is examined, and Higgs masses are computed using the effective potential, including two-loop contributions from scalars. A 125 GeV Higgs is compatible with stops/sbottoms at around 300 GeV with non-universal boundary conditions at the scale of the heavy sparticles if some of th…
It is well-known that heterotic string compactifications have, in spite of their conceptual simplicity and aesthetic appeal, a serious problem with precision gauge coupling unification in the perturbative regime of string theory. Using both a duality-based and a field-theoretic definition of the boundary of the perturbative regime, we reevaluate the situation in a quantitative manner. We conclude that the simplest and most promising situations are those where some of the compactification radii are exceptionally large, corresponding to highly anisotropic orbifold models. Thus, one is led to con…
Despite the compelling simplicity of minimal supersymmetric unification, the proton does not decay as predicted. A possible explanation is that real unification takes place in a theory which is an electric dual of the MSSM GUT with messengers, which has Landau poles below the GUT scale. As was recently pointed out, unification predictions would be transmitted across such a duality, but proton decay would be negligible. In this paper we present electric Seiberg-duals for the minimal supersymmetric SU(5) GUT (plus messengers) that realise this idea, one particularly nice example being an asympto…
In supersymmetric models extended with a gauge singlet the mass of the lightest Higgs boson has contributions proportional to the adimensional coupling $λ$. In minimal scenarios, the requirement that this coupling remains perturbative up to the unification scale constrains $λ$ to be smaller than $\approx 0.7$. We study the maximum value of $λ$ consistent with a perturbative unification of the gauge couplings in models containing nonstandard fields at intermediate scales. These fields appear in scenarios with gauge mediation of supersymmetry breaking. We find that the presence of extra fields c…
We present a model where early inflation and late accelerating expansion of the Universe are driven by the real and imaginary parts of a single complex scalar field, which we identified as inflaton and phantom field, respectively. This inflaton-phantom unification is protected by an internal SO(1,1) symmetry, with the two cosmological scalars appearing as the degrees of freedom of a sole fundamental representation. The unification symmetry allows to build successful potentials. We observe that our theory provides a matter-phantom duality, which transforms scalar matter cosmological solutions i…
This work is an extension of our previous work, hep-th/0204160, which showed how to systematically calculate the high energy evolution of gauge couplings in compact AdS_5 backgrounds. We first directly compute the one-loop effects of massive charged scalar fields on the low energy couplings of a gauge theory propagating in the AdS background. It is found that scalar bulk mass scales (which generically are of order the Planck scale) enter only logarithmically in the corrections to the tree-level gauge couplings. As we pointed out previously, we show that the large logarithms that appear in the …
We propose a mechanism for generating the GUT scale dynamically from the Planck scale. The idea is that the GUT scale is fixed by the vacuum expectation value of a "GUT modulus" field whose potential is exactly flat in the supersymmetric limit. If supersymmetry is broken by gauge mediation, a potential for the GUT modulus is generated at 2 loops, and slopes away from the origin for a wide range of parameters. This potential is stabilized by Planck-suppressed operators in the Kahler potential, and the GUT scale is fixed to be of order M_* / (4π^2) (where M_* ~ 10^{18} GeV is the reduced Planck …
We construct a minimal supersymmetric SO(10) grand unified model in 5 dimensions. The extra dimension is compactified on an S^1/(Z_2 x Z_2^\prime) orbifold which has two in-equivalent fixed points. These are flat 4-dimensional Minkowski spaces: the visible and the hidden branes. By orbifolding, the gauge symmetry on the hidden brane is reduced down to the Pati--Salam gauge symmetry SU(4) x SU(2)_L x SU(2)_R. On the visible brane the SO(10) is broken by the ordinary Higgs mechanism down to SU(5). The resulting 4-dimensional theory has the standard model gauge symmetry (the intersection of SU(5)…
The SUSY contributions $Δa_μ$ to muon $g-2$ anomaly can not even reach $3σ$ in ordinary gauge mediated SUSY breaking (GMSB) scenarios because of the strong correlations between the colored sparticle masses and the uncolored EW sparticle masses. An interesting extension to GMSB is the (Extra)Ordinary Gauge Mediation (EOGM), which can relax the correlations between squarks and sleptons with non-universal choices for $N_{eff,3}$ and $N_{eff,2}$. We find that EOGM scenarios with $N_{eff,3}\ll N_{eff,2}$ can explain the muon $g-2$ anomaly within $3σ$ range, however can not explain the new W-boson m…
We investigate the effects of messenger-matter mixing on the lightest CP-even Higgs boson mass m_h in gauge-mediated supersymmetry breaking models. It is shown that with such mixings m_h can be raised to about 125 GeV, even when the superparticles have sub-TeV masses, and when the gravitino has a cosmologically preferred sub-keV mass. In minimal gauge mediation without messenger-matter mixing, realizing m_h = 125 GeV would require multi-TeV SUSY spectrum. The increase in $m_h$ due to messenger-matter mixing is maximal in the case of messengers belonging to 10+\bar{10} of SU(5) unification, whi…
Influenced by the current trend of experimental data, especially from the LHC, we construct a supersymmetric scenario where a natural dynamics makes the squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion of two underlying ideas: ($i$) gauge mediation of supersymmetry breaking with two messenger multiplets, one transforming as a triplet of weak SU(2) and the other as an octet of color SU(3); ($ii$) perturbative gauge coupling unification at the string scale even with these incomplete SU(5) mu…
