Unification and Dark Matter in a Minimal Scalar Extension of the Standard Model

The six Higgs doublet model is a minimal extension of the Standard Model that addresses dark matter and gauge coupling unification. Another Higgs doublet in a 5 representation of a discrete symmetry group, such as S_6, is added to the SM. The lightest components of the 5-Higgs are neutral, stable and serve as dark matter so long as the discrete symmetry is not broken. Direct and indirect detection signals, as well as collider signatures are discussed. The five-fold multiplicity of the dark matter decreases its mass and typically helps make the dark matter more visible in upcoming experiments.Comment: 10 pages, 7 figures; added references; corrected typo

Here be Dragons: The Unexplored Continents of the CMSSM

The Higgs boson mass and the abundance of dark matter constrain the CMSSM/mSUGRA supersymmetry breaking inputs. A complete map of the CMSSM that is consistent with these two measured quantities is provided. Various "continents," consisting of non-excluded models, can be organized by their dark matter dynamics. The following mechanisms manifest: well-tempering, resonant pseudo-scalar Higgs annihilation, neutralino/stau coannihilations and neutralino/stop coannihilations. Benchmark models are chosen in order to characterize the viable regions. The expected visible signals of each are described, demonstrating a wide range of predictions for the 13 TeV LHC and a high degree of complementarity between dark matter and collider experiments. The parameter space spans a finite volume, which can be probed in its entirety with experiments currently under consideration.Comment: 58 pages + references, 21 figures, data files included on arXiv; v2: references added, minor changes; v3: journal version, minor change

Parity Violation in Composite Inelastic Dark Matter Models

Recent experimental results indicate that the dark matter sector may have a non-minimal structure with a spectrum of states and interactions. Inelastic scattering has received particular attention in light of DAMA's annual modulation signal. Composite inelastic dark matter (CiDM) provides a dynamical origin for the mass splittings in inelastic dark matter models. We show that higher dimensional operators in the CiDM Lagrangian lead to an admixture of inelastic and elastic scattering in the presence of parity violation. This scenario is consistent with direct detection experiments, even when parity violation is nearly maximal. We present an effective field theory description of such models and discuss the constraints from direct detection experiments. The CiDM model with parity violation has non-trivial phenomenology because of the multiple scattering channels that are allowed.Comment: 10 pages, 3 figure

"Interaction-Free" Imaging

Using the complementary wave- and particle-like natures of photons, it is possible to make ``interaction-free'' measurements where the presence of an object can be determined with no photons being absorbed. We investigated several ``interaction-free'' imaging systems, i.e. systems that allow optical imaging of photosensitive objects with less than the classically expected amount of light being absorbed or scattered by the object. With the most promising system, we obtained high-resolution (10 \mu m), one-dimensional profiles of a variety of objects (human hair, glass and metal wires, cloth fibers), by raster scanning each object through the system. We discuss possible applications and the present and future limits for interaction-free imaging.Comment: 10 pages, 6 encapsulated Postscript figure files, accepted for publication in Physical Review

JT9D jet engine performance deterioration

The analytical techniques utilized to examine the effects of flight loads and engine operating conditions on performance deterioration are presented. The role of gyroscopic, gravitational, and aerodynamic loads are shown along with the effect of variations in engine build clearances. These analytical results are compared to engine test data along with the correlation between analytically predicted and measured clearances and rub patterns. Conclusions are drawn and important issues are discussed