A Couplet from Flavored Dark Matter

We show that a couplet, a pair of closely spaced photon lines, in the X-ray spectrum is a distinctive feature of lepton flavored dark matter models for which the mass spectrum is dictated by Minimal Flavor Violation. In such a scenario, mass splittings between different dark matter flavors are determined by Standard Model Yukawa couplings and can naturally be small, allowing all three flavors to be long-lived and contribute to the observed abundance. Then, in the presence of a tiny source of flavor violation, heavier dark matter flavors can decay via a dipole transition on cosmological timescales, giving rise to three photon lines. The ratios of the line energies are completely determined in terms of the charged lepton masses, and constitute a firm prediction of this framework. For dark matter masses of order the weak scale, the couplet lies in the keV-MeV region, with a much weaker line in the eV-keV region. This scenario constitutes a potential explanation for the recent claim of the observation of a 3.5 keV line. The next generation of X-ray telescopes may have the necessary resolution to resolve the double line structure of such a couplet.Comment: 17 pages, 4 figures, 1 haik

Integrated Computer Aided Planning and Manufacture of Advanced Technology Jet Engines

This paper highlights an attempt at evolving a computer aided manufacturing system on a personal computer. A case study of an advanced technology jet engine component is included to illustrate various outputs from the system. The proposed system could be an alternate solution to sophisticated and expensive CAD/CAM workstations

Natural Little Hierarchy from a Partially Goldstone Twin Higgs

We construct a simple theory in which the fine-tuning of the standard model is significantly reduced. Radiative corrections to the quadratic part of the scalar potential are constrained to be symmetric under a global U(4) x U(4)' symmetry due to a discrete Z_2 "twin" parity, while the quartic part does not possess this symmetry. As a consequence, when the global symmetry is broken the Higgs fields emerge as light pseudo-Goldstone bosons, but with sizable quartic self-interactions. This structure allows the cutoff scale, \Lambda, to be raised to the multi-TeV region without significant fine-tuning. In the minimal version of the theory, the amount of fine-tuning is about 15% for \Lambda = 5 TeV, while it is about 30% in an extended model. This provides a solution to the little hierarchy problem. In the minimal model, the "visible" particle content is exactly that of the two Higgs doublet standard model, while the extended model also contains extra vector-like fermions with masses ~(1-2)TeV. At the LHC, our minimal model may appear exactly as the two Higgs doublet standard model, and new physics responsible for cutting off the divergences of the Higgs mass-squared parameter may not be discovered. Several possible processes that may be used to discriminate our model from the simple two Higgs doublet model are discussed for the LHC and for a linear collider.Comment: 22 page

Physiological studies on dormancy in grape seeds (Vitis vinifera) 1. On the naturally occurring growth substances in grape seeds and their changes during low temperature after ripening

In order to understand the hormonal factors affecting dormancy in grape seeds, studies were conducted on the endogenous auxins, inhibitcrs and gibberellin-like substances in the seeds stored moist at 5° C and at room temperature .The results show that moist after-ripening at 5° C resulted in an increase in the amount of growth promoting substances similar to auxins, in the extracts of chilled seeds. No correlation was observed between the content of inhibitor and dormancy in grape seeds. The extracts of neither chilled nor non-chilled seeds showed the presence of gibberellin-like substances when tested on D5 dwarf maize mutant plants.In the light of these findings, it is proposed that an increased synthesis of growth promoting substances during stratification may be one of the factors responsible for the termination of dormancy and resumption of germination of grape seeds