Testing Split Supersymmetry with Inflation

Split supersymmetry (SUSY) -- in which SUSY is relevant to our universe but largely inaccessible at current accelerators -- has become increasingly plausible given the absence of new physics at the LHC, the success of gauge coupling unification, and the observed Higgs mass. Indirect probes of split SUSY such as electric dipole moments (EDMs) and flavor violation offer hope for further evidence but are ultimately limited in their reach. Inflation offers an alternate window into SUSY through the direct production of superpartners during inflation. These particles are capable of leaving imprints in future cosmological probes of primordial non-gaussianity. Given the recent observations of BICEP2, the scale of inflation is likely high enough to probe the full range of split SUSY scenarios and therefore offers a unique advantage over low energy probes. The key observable for future experiments is equilateral non-gaussianity, which will be probed by both cosmic microwave background (CMB) and large scale structure (LSS) surveys. In the event of a detection, we forecast our ability to find evidence for superpartners through the scaling behavior in the squeezed limit of the bispectrum.Comment: 19 pages, 6 figure

Exponential Hierarchies from Anderson Localization in Theory Space

We present a new mechanism for generating exponential hierarchies in four-dimensional field theories inspired by Anderson localization in one dimension, exploiting an analogy between the localization of electron energy eigenstates along a one-dimensional disordered wire and the localization of mass eigenstates along a local "theory space" with random mass parameters. Mass eigenstates are localized even at arbitrarily weak disorder, with exponentially suppressed couplings to sites in the theory space. The mechanism is quite general and may be used to exponentially localize fields of any spin. We apply the localization mechanism to two hierarchies in Standard Model parameters --- the smallness of neutrino masses and the ordering of quark masses --- and comment on possible relevance to the electroweak hierarchy problem. This raises the compelling possibility that some of the large hierarchies observed in and beyond the Standard Model may result from disorder, rather than order.Comment: 5 pages and 1 figur

The Fraternal WIMP Miracle

We identify and analyze thermal dark matter candidates in the fraternal twin Higgs model and its generalizations. The relic abundance of fraternal twin dark matter is set by twin weak interactions, with a scale tightly tied to the weak scale of the Standard Model by naturalness considerations. As such, the dark matter candidates benefit from a "fraternal WIMP miracle," reproducing the observed dark matter abundance for dark matter masses between 50 and 150 GeV. However, the couplings dominantly responsible for dark matter annihilation do not lead to interactions with the visible sector. The direct detection rate is instead set via fermionic Higgs portal interactions, which are likewise constrained by naturalness considerations but parametrically weaker than those leading to dark matter annihilation. The predicted direct detection cross section is close to current LUX bounds and presents an opportunity for the next generation of direct detection experiments.Comment: 22 pages, 6 figures. v2: Relic abundance calculations revised and improved, citations added. Conclusions largely unchanged. v3: Minor changes, accepted by JCA

The New Flavor of Higgsed Gauge Mediation

Recent LHC bounds on squark masses combined with naturalness and flavor considerations motivate non-trivial sfermion mass spectra in the supersymmetric Standard Model. These can arise if supersymmetry breaking is communicated to the visible sector via new extended gauge symmetries. Such extended symmetries must be spontaneously broken, or confined, complicating the calculation of soft masses. We develop a new formalism for calculating perturbative gauge-mediated two-loop soft masses for gauge groups with arbitrary patterns of spontaneous symmetry breaking, simplifying the framework of "Higgsed gauge mediation." The resulting expressions can be applied to Abelian and non-Abelian gauge groups, opening new avenues for supersymmetric model building. We present a number of examples using our method, ranging from grand unified threshold corrections in standard gauge mediation to soft masses in gauge extensions of the Higgs sector that can raise the Higgs mass through non-decoupling D-terms. We also outline a new mediation mechanism called "flavor mediation", where supersymmetry breaking is communicated via a gauged subgroup of Standard Model flavor symmetries. Flavor mediation can automatically generate suppressed masses for third-generation squarks and implies a nearly exact U(2) symmetry in the first two generations, yielding a "natural SUSY" spectrum without imposing ad hoc global symmetries or giving preferential treatment to particular generations.Comment: 13 pages, 3 figures; v2: typos corrected, references adde

Twin Turtles

We present an ultraviolet extension of the Twin Higgs in which the radial mode of twin symmetry breaking is itself a pseudo-goldstone boson. This "turtle" structure raises the scale of new colored particles in exchange for additional states in the Higgs sector, making multiple Higgs-like scalars the definitive signature of naturalness in this context. We explore the parametrics and phenomenology of a concrete Twin Turtle model and demonstrate its robustness in two different supersymmetric completions. Along the way, we also introduce a new mechanism for inducing hard twin symmetry-breaking quartics via soft supersymmetry breaking.Comment: 36 pages, 13 figure