Multicomponent Dark Matter in Supersymmetric Hidden Sector Extensions

Most analyses of dark matter within supersymmetry assume the entire cold dark matter arising only from weakly interacting neutralinos. We study a new class of models consisting of $U(1)^n$ hidden sector extensions of the MSSM that includes several stable particles, both fermionic and bosonic, which can be interpreted as constituents of dark matter. In one such class of models, dark matter is made up of both a Majorana dark matter particle, i.e., a neutralino, and a Dirac fermion with the current relic density of dark matter as given by WMAP being composed of the relic density of the two species. These models can explain the PAMELA positron data and are consistent with the anti-proton flux data, as well as the photon data from FERMI-LAT. Further, it is shown that such models can also simultaneously produce spin independent cross sections which can be probed in CDMS-II, XENON-100 and other ongoing dark matter experiments. The implications of the models at the LHC and at the NLC are also briefly discussed.Comment: Journal: Physical Review D, Latex 32 pages, 4 eps figure

Predictions in SU(5) Supergravity Grand Unification with Proton Stability and Relic Density Constraints

It is shown that in the physically interesting domain of the parameter space of SU(5) supergravity GUT, the Higgs and the Z poles dominate the LSP annihilation. Here the naive analyses on thermal averaging breaks down and formulae are derived which give a rigorous treatment over the poles. These results are then used to show that there exist significant domains in the parameter space where the constraints of proton stability and cosmology are simultaneously satisfied. New upper limits on light particle masses are obtained.Comment: (An error in the reheating factor is corrected, strengthening the conclusions, i.e. the region in parameter space where the relic density constraints are satisfied is enlarged.

Gandlieri ta’ l-Isqof

Ġabra ta’ poeżiji u proża li tinkludi: Żewġ Qronfliet ta’ Dun Karm – Ġustizzja Bla Qorti ta’ Ġużè Galea – It-Tigra u l-Ħamiema ta’ A. Buttigieg – Ġewwa l-Presepju ta’ R. M. B. – Salvu Jsir Missier ta’ Vic. Apap – Madlien ta’ K. G. M. F. – Imbierek il-Mulej! ta’ Pran. Camilleri – Il-Gandlieri ta’ l-Isqof ta’ V. Hugo u maqlub għall-Malti minn G. Z. A.N/

Defect-mediated metastability and carrier lifetimes in polycrystalline (Ag,Cu)(In,Ga)Se-2 absorber materials

Using a combination of optical and electrical measurements, we develop a model for metastable defects in Ag-alloyed Cu(In,Ga)Se-2, one of the leading thin film photovoltaic materials. By controlling the pre-selenization conditions of the back contact prior to the growth of polycrystalline (Ag,Cu)(In,Ga)Se-2 absorbers and subsequently exposing them to various stresses (light soaking and dark-heat), we explore the nature and role of metastable defects on the electro-optical and photovoltaic performance of high-efficiency solar cell materials and devices. Positron annihilation spectroscopy indicates that dark-heat exposure results in an increase in the concentration of the selenium-copper divacancy complex (V-Se-V-Cu), attributed to depassivation of donor defects. Deep-level optical spectroscopy finds a corresponding increase of a defect at E-v+0.98eV, and deep-level transient spectroscopy suggests that this increase is accompanied by a decrease in the concentration of mid-bandgap recombination centers. Time-resolved photoluminescence excitation spectroscopy data are consistent with the presence of the V-Se-V-Cu divacancy complex, which may act as a shallow trap for the minority carriers. Light-soaking experiments are consistent with the V-Se-V-Cu optical cycle proposed by Lany and Zunger, resulting in the conversion of shallow traps into recombination states that limit the effective minority carrier recombination time (and the associated carrier diffusion length) and an increase in the doping density that limits carrier extraction in photovoltaic devices.Peer reviewe

High Scale Physics Connection to LHC Data

The existing data appears to provide hints of an underlying high scale theory. These arise from the gauge coupling unification, from the smallness of the neutrino masses, and via a non-vanishing muon anomaly. An overview of high scale models is given with a view to possible tests at the Large Hadron Collider. Specifically we discuss here some generic approaches to deciphering their signatures. We also consider an out of the box possibility of a four generation model where the fourth generation is a mirror generation rather than a sequential generation. Such a scenario can lead to some remarkably distinct signatures at the LHC.Comment: 23 pages, no figures. Based on invited lectures at the 46th Course at the International School of Subnuclear Physics- Erice -Sicily: 29 August -7 September, 200

Beneficial impacts of goat milk on the nutritional status and general well-being of human beings: Anecdotal evidence

Goats provide an essential food supply in the form of milk and meat. Goat milk has distinct qualities, but it shares many similarities with human and bovine milk regarding its nutritional and therapeutic benefits. Because of their different compositions, goat and cow milk products could have different tastes, nutrients, and medicinal effects. Modification in composition aid of goat milk determining the viability of goat milk processing methods. Comparatively, goat's milk has higher calcium, magnesium, and phosphorus levels than cow's or human milk but lower vitamin D, B12, and folate levels. Goat milk is safe and healthy for infants, the old, and healing ailments. Capric, caprylic, and capric acid are three fatty acids that have shown promise as potential treatments for various medical issues. Considering the benefits and drawbacks of goat milk over cow milk is essential; goat milk is more digestible, has unique alkalinity, has a better buffering capacity, and has certain medicinal benefits. Acidifying goat milk shrinks fat globules and makes protein friable (with less αs1-casein and more αs2-casein). Goat milk treats malabsorption illnesses because it has more short- and medium-chain triglycerides that give developing children energy. In wealthy countries, goat milk and its products—yoghurt, cheeses, and powdered goods—are popular with connoisseurs and persons with allergies and gastrointestinal issues who need alternative dairy products. A food product category containing fermented goat milk with live probiotic microbes appears promising nutritionally and medicinally. This article presents anecdotal evidence of the therapeutic effects of consuming goat milk for human health and its nutritional value

Constraints on the minimal supergravity model from the b->s+\gamma decay

The constraints on the minimal supergravity model from the b->s+\gamma decay are studied. A large domain in the parameter space for the model satisfies the CLEO bound, BR(b->s+\gamma)<5.4X10^{-4}. However, the allowed domain is expected to diminish significantly with an improved bound on this decay. The dependence of the b->s+\gamma branching ratio on various parameters is studied in detail. It is found that, for A_t<0 and the top quark mass within the vicinity of the center of the CDF value, m_t^{pole}=174\pm17 GeV, there exists only a small allowed domain because the light stop is tachyonic for most of the parameter space. A similar phenomenon exists for a lighter top and A_t negative when the GUT coupling constant is slightly reduced. For A_t>0, however, the branching ratio is much less sensitive to small changes in m_t, and \alpha_G.Comment: 12 pages, plain tex file, three figures avaliable upon request, CTP-TAMU-03/94, NUB-TH.7316/94, and CERN-TH.3092/9

Beneficial health effects of cumin (Cuminum cyminum) seeds upon incorporation as a potential feed additive in livestock and poultry: A mini-review

Cumin (Cuminum cyminum Linn) is an annual plant of the family Umbelliferae, with its use dating back to ancient times when it was cultivated for its medicinal and culinary potential. Cumin seeds could contain a wide variety of phytochemicals, including alkaloids, coumarins, anthraquinones, flavonoids, glycosides, proteins, resins, saponins, tannins, and steroids. In particular, linoleic acid, one of the unsaturated fatty acids found in abundance in cumin oleoresin, is credited with promoting good health. Many of cumin's purported biological actions in livestock and poultry have been attributed to flavonoids such as apigenin, luteolin, and glycosides. Cumin has several healthful qualities, such as antibacterial, insecticidal, anti-inflammatory, analgesic, antioxidant, anticancer, anti-diabetic, anti-platelet aggregation, hypotensive, bronchodilatory, immunological, anti-amyloidogenic, and anti-osteoporotic properties. Cumin supplementation may improve milk production and reproductive function in dairy cows by altering the feeding pattern of bacteria in the rumen, encouraging the growth of beneficial microbes, or stimulating the secretion of certain digestive enzymes. Because of the low price of cumin seed, it could be concluded that its inclusion in the diet might be beneficial to the commercial poultry industry and reduce the overall cost of egg and meat production. In recent years a rise in cumin's popularity has been seen as a result of the herbal movement spearheaded by naturopaths, yoga gurus, advocates of alternative medicine, and manufacturers of feed additives. Animal nutritionists are exploring the use of cumin for its potential to boost growth, improve nutrient usage efficiency, and reduce greenhouse gas emissions. This mini-review discusses how cumin could be used as a feed ingredient to boost productivity and ensure healthy animal reproduction

Status of the LUX Dark Matter Search

The Large Underground Xenon (LUX) dark matter search experiment is currently being deployed at the Homestake Laboratory in South Dakota. We will highlight the main elements of design which make the experiment a very strong competitor in the field of direct detection, as well as an easily scalable concept. We will also present its potential reach for supersymmetric dark matter detection, within various timeframes ranging from 1 year to 5 years or more.Comment: 4 pages, in proceedings of the SUSY09 conferenc

Effects of CP Violation on Event Rates in the Direct Detection of Dark Matter

A full analytic analysis of the effects of CP violating phases on the event rates in the direct detection of dark matter in the scattering of neutralinos from nuclear targets is given. The analysis includes CP violating phases in softly broken supersymmetry in the framework of the minimal supersymmetric standard model (MSSM) when generational mixings are ignored. A numerical analysis shows that large CP violating phases including the constraints from the experimental limits on the neutron and the electron electric dipole moment (EDM) can produce substantial effects on the event rates in dark matter detectors.Comment: 17 pages, LaTex, including 2 figures; revised version to appear in the Physical Review