Flavor and CP violating physics from new supersymmetric thresholds

Treating the MSSM as an effective theory, we study the implications of having dimension five operators in the superpotential for flavor and CP-violating processes, exploiting the linear decoupling of observable effects with respect to the new threshold scale \Lambda. We show that the assumption of weak scale supersymmetry, when combined with the stringent limits on electric dipole moments and lepton flavor-violating processes, provides sensitivity to \Lambda as high as 10^7-10^9 GeV, while the next generation of experiments could directly probe the high-energy scales suggested by neutrino physics.Comment: 4 pages, 1 figur

Notes on the Norman vocabulary

The Norman Manuscript, containing- a vocabulary and notes on customs in use among Tasmanian Aboriginals, was recently discovered among the archives deposited in the Tasmanian Museum, Hobart, and is now published in full in the Transactions of the Royal Society of Tasmania. It is of great value, as containing what is probably the only vocabulary now extant in the original manuscript, and also a number of incidental notes written by the same hand

Analysis of broadband microwave conductivity and permittivity measurements of semiconducting materials

We perform broadband phase sensitive measurements of the reflection coefficient from 45 MHz up to 20 GHz employing a vector network analyzer with a 2.4 mm coaxial sensor which is terminated by the sample under test. While the material parameters (conductivity and permittivity) can be easily extracted from the obtained impedance data if the sample is metallic, no direct solution is possible if the material under investigation is an insulator. Focusing on doped semiconductors with largely varying conductivity, here we present a closed calibration and evaluation procedure for frequencies up to 5 GHz, based on the rigorous solution for the electromagnetic field distribution inside the sample combined with the variational principle; basically no limiting assumptions are necessary. A simple static model based on the electric current distribution proves to yield the same frequency dependence of the complex conductivity up to 1 GHz. After a critical discussion we apply the developed method to the hopping transport in Si:P at temperature down to 1 K.Comment: 9 pages, 10 figures, accepted for publication in the Journal of Applied Physic

Resonant scattering and recombination of pseudo-degenerate WIMPs

We consider the direct and indirect detection signatures of WIMPs \chi^0 in kinematic regimes with a heavier, but nearly degenerate, charged state \chi^{+-}. For small splittings of O(10) MeV, the scattering of WIMPs off nuclei may be dominated by inelastic recombination processes mediated by the formation of (\chi^- N) bound states, leading to a distinct signature for direct detection. These cross-sections are bound primarily by limits on the abundance of heavy isotopes, and may be considerably larger than the elastic scattering cross section in more conventional models. If the mass splitting is too large for recombination to occur, there may still be a significant resonant enhancement of loop-induced electromagnetic form-factors of the WIMP, which can enhance the elastic scattering cross-section. We also discuss how this regime affects the annihilation cross-section and indirect detection signatures, and note the possibility of a significant mono-energetic \gamma-signal, mediated by resonant processes near the (\chi^+\chi^-) bound state threshold.Comment: 22 pages, 6 figures; v2: typos corrected, to appear in Phys. Rev.

Sensitivity to new supersymmetric thresholds through flavour and CP violating physics

Treating the MSSM as an effective theory below a threshold scale Lambda, we study the consequences of having dimension-five operators in the superpotential for flavour and CP-violating processes. Below the supersymmetric threshold such terms generate flavour changing and/or CP-odd effective operators of dimension six composed from the Standard Model fermions, that have the interesting property of decoupling linearly with the threshold scale, i.e. as 1/(Lambda m_soft), where m_soft is the scale of soft supersymmetry breaking. The assumption of weak-scale supersymmetry, together with the stringent limits on electric dipole moments and lepton flavour-violating processes, then provides sensitivity to Lambda as high as 10^7-10^9 GeV. We discuss the varying sensitivity to these scales within several MSSM benchmark scenarios and also outline the classes of UV physics which could generate these operators.Comment: 28 pages, 9 figure

Secluded WIMP Dark Matter

We consider a generic mechanism via which thermal relic WIMP dark matter may be decoupled from the Standard Model, namely through a combination of WIMP annihilation to metastable mediators with subsequent delayed decay to Standard Model states. We illustrate this with explicit examples of WIMPs connected to the Standard Model by metastable bosons or fermions. In all models, provided the WIMP mass is greater than that of the mediator, it can be secluded from the Standard Model with an extremely small elastic scattering cross-section on nuclei and rate for direct collider production. In contrast, indirect signatures from WIMP annihilation are consistent with a weak scale cross-section and provide potentially observable \gamma-ray signals. We also point out that \gamma-ray constraints and flavor physics impose severe restrictions on MeV-scale variants of secluded models, and identify limited classes that pass all the observational constraints.Comment: 17 pages, 3 figure