Metastable Supersymmetry Breaking Research Articles

Leptogenesis from composite singlets

We argue that dual singlets accommodate the thermal leptogenesis in the context of metastable supersymmetry breaking. This framework suggests that the reheating temperature is as low as O(104) GeV, and besides the neutrino masses, solely induced from the dual fermions, are present at O(0.1) eV. We also expect that the unstable gravitino, though long-lived, may cause a clear signal of the neutrino flux at O(10) MeV. Published by the American Physical Society 2024

Gravitational waves in metastable supersymmetry breaking

If supersymmetry is broken in metastable vacua, it is not clear why we are now in there rather than supersymmetric vacua. Moreover, it is natural to expect that we were in supersymmetric vacua, which have higher symmetry than metastable vacua, in the early universe. In this paper, we reexamine and improve the previous analysis on the cosmological evolution of the vacuum structure in the ISS model of metastable supersymmetry breaking by taking into account constraints on the reheating temperature, which is needed to avoid the overproduction of gravitinos. It turns out that the desired phase transition from a supersymmetric vacuum to a metastable vacuum is allowed only in the light gravitino mass region $m_{3/2} < 4.7$ eV. This is achieved by either rolling down potential or tunneling processes depending on the reheating temperature. We show that when the tunneling processes are realized, abundant gravitational waves could be produced from collisions of runaway bubbles. The resulting gravitational waves are detectable with the future gravitational wave interferometers like LISA and DECIGO.

FIMP dark matter freeze-in gauge mediation and hidden sector

We explore the dark matter freeze-in mechanism within the gauge mediation framework, which involves a hidden feebly interacting massive particle (FIMP) coupling feebly with the messenger fields while the messengers are still in the thermal bath. The FIMP is the fermionic component of the pseudo-moduli in a generic metastable supersymmetry (SUSY) breaking model and resides in the hidden sector. The relic abundance and the mass of the FIMP are determined by the SUSY breaking scale and the feeble coupling. The gravitino, which is the canonical dark matter candidate in the gauge mediation framework, contributes to the dark matter relic abundance along with the freeze-in of the FIMP. The hidden sector thus becomes two-component with both the FIMP and gravitino lodging in the SUSY breaking hidden sector. We point out that the ratio between the FIMP and the gravitino is determined by how SUSY breaking is communicated to the messengers. In particular when the FIMP dominates the hidden sector, the gravitino becomes the minor contributor in the hidden sector. Meanwhile, the neutralino is assumed to be both the weakly interacting massive particle dark matter candidate in the freeze-out mechanism and the lightest observable SUSY particle. We further find out the neutralino has the sub-leading contribution to the current dark matter relic density in the parameter space of our freeze-in gauge mediation model. Our result links the SUSY breaking scale in the gauge mediation framework with the FIMP freeze-in production rate leading to a natural and predicting scenario for the studies of the dark matter in the hidden sector.

No-go theorem for fully supersymmetric GUTs with metastable supersymmetry breaking

We introduce fully SGUTs, SUSY grand unified theories that, upon symmetry breaking through the Higgs mechanism, decompose into a visible sector and an extra sector where the dynamics of the extra sector gauge group is responsible for SUSY breaking. Fully SGUTs thus have the important feature that all gauge groups of the visible sector and the extra sector unify into a simple gauge group at the SGUT scale, therefore generalizing the successful MSSM gauge coupling unification to all the gauge couplings of the theory. By focusing on the ISS SUSY-breaking mechanism in the extra sector, we show that it is impossible to reproduce the MSSM matter content when there exists a metastable ISS SUSY-breaking state.

Limits on new physics from black holes

Black holes emit high energy particles which induce a finite density potential for any scalar field $\phi$ coupling to the emitted quanta. Due to energetic considerations, $\phi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\phi$ resides at a metastable minimum, this effect can drive $\phi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\phi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

New self-dualities and duality cascades

New self-dualities involving two index tensors are derived. These new self-dualities are used to build various duality cascades. Both vector like and chiral cascades are presented. Aside from ending in confinement, these duality cascades can also end in interacting conformal field theories, free field theories, and meta-stable supersymmetry breaking. Higgsing effects are built into the self-duality so that when the gauge groups are small enough, supersymmetry is broken through the rank condition. Dynamical supersymmetry restoration occurs far from the SUSY breaking vacuum resulting in a long lived meta-stable vacuum. It is found that Coulomb branches are critical in the stabilization of runaways and dynamical supersymmetry restoration.

SUPERSYMMETRY BREAKING IN ANTI-DE SITTER SPACE–TIME

We study the questions of how supersymmetry is spontaneously broken in anti-de Sitter space–time. We verify that the would-be R-symmetry in AdS4 plays a central role for the existence of meta-stable supersymmetry breaking. To illustrate, some well-known models such as Poloyni models and O'Raifeartaigh models are investigated in detail. Our calculations are reliable in flat space–time limit and confirm us that meta-stable vacua are generic even though quantum corrections are taken into account.

Metastable spontaneous breaking of [formula omitted] supersymmetry

We show that contrary to the common lore it is possible to spontaneously break N=2 supersymmetry even in simple theories without constant Fayet–Iliopoulos terms. We consider the most general N=2 supersymmetric theory with one hypermultiplet and one vector multiplet without Fayet–Iliopoulos terms, and show that metastable supersymmetry breaking vacua can arise if both the hyper-Kähler and the special-Kähler geometries are suitably curved. We then also prove that while all the scalars can be massive, the lightest one is always lighter than the vector boson. Finally, we argue that these results also directly imply that metastable de Sitter vacua can exist in N=2 supergravity theories with Abelian gaugings and no Fayet–Iliopoulos terms, again contrary to common lore, at least if the cosmological constant is sufficiently large.

Simple metastable de Sitter vacua in N=2 gauged supergravity

We construct a simple class of N=2 gauged supergravity theories that admit metastable de Sitter vacua, generalizing the recent work done in the context of rigid supersymmetry. The setup involves one hypermultiplet and one vector multiplet spanning suitably curved quaternionic-Kähler and special-Kähler geometries, with an Abelian gauging based on a single triholomorphic isometry, but neither Fayet-Iliopoulos terms nor non-Abelian gauge symmetries. We construct the most general model of this type and show that in such a situation the possibility of achieving metastable supersymmetry breaking vacua crucially depends on the value of the cosmological constant V relative to the gravitino mass squared $ m_{{{3 \left/ {2} \right.}}}^2 $ in Planck units. In particular, focusing on de Sitter vacua with positive V, we show that metastability is only possible when $ V\gtrsim 2.17m_{{{3 \left/ {2} \right.}}}^2 $ . We also derive an upper bound on the lightest scalar mass in this kind of model relative to the gravitino mass m 3/2 as a function of the cosmological constant V, and discuss its physical implications.

Stringy hidden valleys

We study gauge theories where quasi-hidden sectors are added to the MSSM for the sake of string consistency conditions which would otherwise not be satisfied. We focus on quiver gauge theories motivated by weakly coupled type II orientifold compactifications. Model independent features in this class include an anomalous U(1)_V symmetry which protects messenger masses and has strong consequences for superpotential couplings, a rich phenomenology of heavy and light Z' bosons, and axionic couplings required for anomaly cancellation via the Green-Schwarz mechanism. We discuss possibilities for dark matter and supersymmetry breaking in light of these generic features. Dark matter is necessarily non-baryonic, though many dark matter candidates have weak interactions. Most models have a U(1)_V Y Y anomaly whose cancellation requires couplings which allow for dark matter annihilation into photons through intermediate axions or anomalous Z' bosons, as in two recently proposed scenarios. There is often an additional non-anomalous U(1) symmetry which can give rise to a Fayet-like model of metastable supersymmetry breaking. Breaking of supersymmetry via SQCD can also be realized and flavor masses are often protected. Natural possibilities for mediation include gauge mediation, Z' mediation, and D-instanton mediation, though it is not possible to realize minimal gauge mediation with messengers added for string consistency.

Assessing a candidate IIA dual to metastable supersymmetry-breaking

Abstract We analyze the space of linearized non-supersymmetric deformations around a IIA solution found by Cvetič, Gibbons, Lü and Pope (CGLP) in hep-th/0101096. We impose boundary conditions aimed at singling out among those perturbations the ones describing the backreaction of anti-D2 branes on the CGLP background. The corresponding supergravity solution is a would-be dual to a metastable supersymmetry-breaking state. However, it turns out that this candidate bulk solution is inevitably riddled with IR divergences of its flux densities and action, whose physical meaning and implications for models of string cosmology call for further investigation.

R-symmetry breaking and O’Raifeartaigh model with global symmetries at finite temperature

We investigate finite temperature effects in O'Raifeartaigh models with global symmetries which exhibit supersymmetry breaking at a metastable vacuum accompanied by $U(1{)}_{R}$ breaking. The pseudomoduli field is stabilized at one-loop order at zero temperature within some coupling parameter region. We analyze the behavior of the parameter space according to nonzero temperatures and find that the parameter region which allows $U(1{)}_{R}$ breaking is considerably extended at sufficiently low temperature, even though it shrinks down at high temperature as expected. We also discuss the thermal history of the metastable supersymmetry breaking vacuum.

A fat Higgs with a magnetic personality

We introduce a novel composite Higgs theory based on confining supersymmetric QCD. Supersymmetric duality plays a key role in this construction, with a "fat" Higgs boson emerging as a dual magnetic degree of freedom charged under the dual magnetic gauge group. Due to spontaneous color-flavor locking in the infrared, the electroweak gauge symmetry is aligned with the dual magnetic gauge group, allowing large Yukawa couplings between elementary matter fields and the composite Higgs. At the same time, this theory exhibits metastable supersymmetry breaking, leading to low-scale gauge mediation via composite messengers. The Higgs boson is heavier than in minimal supersymmetric theories, due to non-decoupling D-terms and a large F-term quartic coupling. This theory predicts quasi-stable TeV-scale pseudo-modulini, some of which are charged under standard model color, possibly giving rise to long-lived R-hadrons at the LHC.

Dynamical SUSY breaking and the β-deformation

We study supersymmetry breaking metastable vacua arising from beta deformed quiver gauge theories. The relation between the bounds on metastability and the deformation are discussed. Metastable supersymmetry breaking vacua are found in the IR of beta deformed cascading quivers with vector-like field content. Furthermore the limiting case of massive Nf=Nc SQCD appears in the IR of gauge theories with chiral-like field content. We comment on the field theory origin of the deformation and on possible applications in AdS/CFT.

R-symmetry matching in supersymmetry breaking models

Low energy descriptions of metastable supersymmetry breaking models often possess an accidental $R$ symmetry. Viable phenomenological applications of this class of models require $R$ symmetry to be broken in the ground state. This can be achieved in O'Raifeartaigh-like models where some of the chiral superfields carry negative $R$ charges. In this paper we consider UV completions of this class of models and formulate necessary conditions that they must satisfy. We show that the $R$ symmetry of the IR description can be traced to an anomalous or anomaly-free $R$ symmetry of the UV theory and discuss several representative examples.

Metastable supersymmetry breaking in extended supergravity

We consider the stability of non-supersymmetric critical points of general N=4 supergravities. A powerful method to analyse this issue based on the sGoldstino direction has been developed for minimal supergravity. We adapt this to the present case, and address the conceptually new features arising for extended supersymmetry. As an application, we investigate the stability when supersymmetry breaking proceeds via either the gravity or the matter sector. Finally, we outline the N=8 case.

Naturalness from runaways in direct mediation

Postulating that the NMSSM singlet is a meson of a microscopic confining theory opens up new model-building possibilities. Based on this, we construct calculable models of direct mediation that solve the mu/Bmu problem and simultaneously lead to realistic phenomenology. The singlet that couples to the Higgs fields develops a runaway produced by soft interactions, then stabilized by a small superpotential perturbation. The mechanism is first realized in an O'Raifeartaigh model of direct gauge mediation with metastable supersymmetry breaking. Focusing then on the microscopic theory, we argue that super QCD with massless and massive flavors in the free magnetic phase gives rise to this dynamics in the infrared. A deformation of the SQCD superpotential leads to large spontaneous R-symmetry breaking, gaugino masses naturally at the scale of the Higgs mass parameters, and absence of CP violating phases.

Inflation and Gauge Mediation in Supersymmetric Gauge Theory

We propose a simple high-scale inflationary scenario based on a phenomenologically viable model with direct gauge mediation of low-scale supersymmetry breaking. Hybrid inflation is occurred in a hidden supersymmetry breaking sector. Two hierarchical mass scales to reconcile both high-scale inflation and gauge mediation are necessary for the stability of the metastable supersymmetry breaking vacuum. Our scenario is also natural in light of the Landau pole problem of direct gauge mediation.

Solitonic supersymmetry restoration

Q-balls are a possible feature of any model with a conserved, global U(1) symmetry and no massless, charged scalars. It is shown that for a broad class of models of metastable supersymmetry breaking they are extremely influential on the vacuum lifetime and make seemingly viable vacua catastrophically short lived. A net charge asymmetry is not required as there is often a significant range of parameter space where statistical fluctuations alone are sufficient. This effect is examined for two supersymmetry breaking scenarios. It is found that models of minimal gauge mediation (which necessarily have a messenger number U(1)) undergo a rapid, supersymmetry restoring phase transition unless the messenger mass is greater than 108 GeV. Similarly the ISS model, in the context of direct mediation, quickly decays unless the perturbative superpotential coupling is greater than the Standard Model gauge couplings.

Cosmological vacuum selection and metastable susy breaking

We study gauge mediation in a wide class of O'Raifeartaigh type models where supersymmetry breaking metastable vacuum is created by gravity and/or quantum corrections. We examine their thermal evolution in the early universe and the conditions under which the susy breaking vacuum can be selected. It is demonstrated that thermalization typically makes the metastable supersymmetry breaking cosmologically disfavoured but this is not always the case. Initial conditions with the spurion displaced from the symmetric thermal minimum and a small coupling to the messenger sector can result in the realization of the susy breaking vacuum even if the reheating temperature is high. We show that this can be achieved without jeopardizing the low energy phenomenology. In addition, we have found that deforming the models by a supersymmetric mass term for messengers in such a way that the susy breaking minimum and the susy preserving minima are all far away from the origin does not change the conclusions. The basic observations are expected to hold also in the case of models with an anomalous U(1) group.