Top and Bottom: a Brane of Their Own

We consider extra dimensional descriptions of models where there are two separate strongly interacting sectors contributing to electroweak symmetry breaking (``topcolor'' type models). In the extra dimensional picture there would be two separate (anti-de Sitter) bulks meeting on the Planck brane, with each bulk having its own corresponding IR (TeV) brane. Sources for electroweak symmetry breaking can then be localized on both of these IR branes, while the different generations of fermions may be separated from each other. We describe the modes propagating in such a setup, and consider the cases where the electroweak symmetry breaking on either of the two IR branes come either from a higgsless scenario (via boundary conditions) or a (top-)Higgs. We show that the tension that exists between obtaining a large top quark mass and the correct value of the Zb\bar{b} couplings in ordinary higgsless models can be largely relieved in the higgsless--top-Higgs versions of the two IR brane models. This may also be true in the purely higgsless--higgsless case, however since that model is necessarily in the strongly coupled regime the tree-level results for the properties of the third generation may get large corrections. A necessary consequence of such models is the appearance of additional pseudo-Goldstone bosons (``top-pions''), which would be strongly coupled to the third generation.Comment: 34 pages, LaTeX, 6 figures. v2: figure 2 fixed, footnote, comments and references adde

Constraints on DD Dimensional Warped Spaces

In order to investigate the phenomenological implications of allowing gauge fields to propagate in warped spaces of more than five dimensions, we consider a toy model of a space warped by the presence of a anisotropic bulk cosmological constant. After solving the Einstein equation, three classes of solutions are found, those in which the additional ($D>5$) dimensions are growing, shrinking or remaining constant. It is found that gauge fields propagating in these spaces have a significantly different Kaluza Klein (KK) mass spectrum and couplings from that of the Randall and Sundrum model. This leads to a greatly reduced lower bound on the KK scale, arising from electroweak constraints, for spaces growing towards the IR brane.Comment: 6 pages, 5 figures PASCOS2010 International Symposium proceedin

Sib-mating does not lead to facultative sex ratio adjustment in the parasitoid wasp, Nasonia vitripennis

Sex ratio theory predicts that in haplodiploid species, females should lay a relatively more female-biased offspring sex ratio when they mate with a sibling compared with when they mate with a non-relative. This is because in haplodiploids, inbreeding leads to females having greater relatedness to daughters relative to sons. This prediction has only been tested in the parasitoid waspNasonia vitripennis, where no support for this prediction was found. However, a limitation of this previous work is that it was carried out with only two females laying eggs per patch. This is a problem, because in this case the predicted difference in the offspring sex ratio is small and therefore hard to detect. We addressed this problem by utilizing a situation in which larger sex ratio differences are predicted – five females laying eggs per patch. Consistent with the previous results, we also found that the offspring sex ratio laid by a female was not influenced by whether she mated with a sibling or non-relative. Meta-analysis of all the experiments we have undertaken confirms this pattern. This failure to respond to the identity of a mating partner suggests females are unable to discriminate kin and is a relatively rare example of maladaptive sex allocation

To God Be the Glory: Discussing Sex in Evangelical Communities in Southern Nigeria

Many people hold stereotypes and assumptions about religious communities in regards to their feelings and beliefs about sex and the impact it has on the lived experiences of religious people. However, stereotypes and assumptions are not often grounded in reality, and many people are hesitant to address the issue head on. This qualitative ethnographically informed preliminary grounded theory study aimed to engage an Evangelical Pentecostal community in Southern Nigeria with the ultimate goal of understanding how communities conceptualize and discuss sexuality topics, the factors influencing sexual decision making amongst youth and young adults, and to identify research needs that will better inform innovative and efficacious research utilizing religious communities in sexuality research. Results showed that this population was highly interested in discussing sexuality in their community including major threats to their ideal sexual behavior path, reasons why people stray from this ideal and how to keep people on this ideal path. This research demonstrates that religious communities are interested in conducting sexuality research so long as the research takes their values and beliefs into account and respects their limitations when it comes to research intent and methods.Keywords: Sexuality, faith-based, Nigeria, community based research, qualitativ

Anomalous Diffusion at Edge and Core of a Magnetized Cold Plasma

Progress in the theory of anomalous diffusion in weakly turbulent cold magnetized plasmas is explained. Several proposed models advanced in the literature are discussed. Emphasis is put on a new proposed mechanism for anomalous diffusion transport mechanism based on the coupled action of conductive walls (excluding electrodes) bounding the plasma drain current (edge diffusion) together with the magnetic field flux "cutting" the area traced by the charged particles in their orbital motion. The same reasoning is shown to apply to the plasma core anomalous diffusion. The proposed mechanism is expected to be valid in regimes when plasma diffusion scales as Bohm diffusion and at high $B/N$, when collisions are of secondary importance.Comment: 9 pages, 4 figure

Light dark forces at flavor factories

SuperB experiment could represent an ideal environment to test a new U (1) symmetry related to light dark forces candidates. A promising discovery channel is represented by the resonant production of a boson U, followed by its decay into lepton pairs. Beyond approximations adopted in the literature, an exact tree level calculation of the radiative processes $e+ e- \rightarrow \gamma, U \rightarrow \mu^+ \mu^- \gamma, e^+ e^- \gamma$ and corresponding QED backgrounds is performed, including also the most important higher-order corrections. The calculation is implemented in a release of the generator BabaYaga@NLO useful for data analysis and interpretation. The distinct features of U boson production are shown and the statistical significance is analysed

Roughness analysis applied to niobium thin films grown on MgO(001) surfaces for superconducting radio frequency cavity applications

This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF) cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of similar to 50 MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [Appl. Phys. Lett. 88, 012511 (2006)] was proposed to overcome this limit that involves coating superconducting layers separated by insulating ones onto the inner walls of the cavities. Thus, we have undertaken a systematic effort to understand the dynamic evolution of the Nb surface under specific deposition thin film conditions onto an insulating surface in order to explore the feasibility of the proposed model. We examine and compare the morphology from two distinct Nb/MgO series, each with its own epitaxial registry, at very low growth rates and closely examine the dynamical scaling of the surface features during growth. Further, we apply analysis techniques such as power spectral density to the specific problem of thin film growth and roughness evolution to qualify the set of deposition conditions that lead to successful SRF coatings. DOI: 10.1103/PhysRevSTAB.16.02200

The S-parameter in Holographic Technicolor Models

We study the S parameter, considering especially its sign, in models of electroweak symmetry breaking (EWSB) in extra dimensions, with fermions localized near the UV brane. Such models are conjectured to be dual to 4D strong dynamics triggering EWSB. The motivation for such a study is that a negative value of S can significantly ameliorate the constraints from electroweak precision data on these models, allowing lower mass scales (TeV or below) for the new particles and leading to easier discovery at the LHC. We first extend an earlier proof of S>0 for EWSB by boundary conditions in arbitrary metric to the case of general kinetic functions for the gauge fields or arbitrary kinetic mixing. We then consider EWSB in the bulk by a Higgs VEV showing that S is positive for arbitrary metric and Higgs profile, assuming that the effects from higher-dimensional operators in the 5D theory are sub-leading and can therefore be neglected. For the specific case of AdS_5 with a power law Higgs profile, we also show that S ~ + O(1), including effects of possible kinetic mixing from higher-dimensional operator (of NDA size) in the $5D$ theory. Therefore, our work strongly suggests that S is positive in calculable models in extra dimensions.Comment: 21 pages, 2 figures. v2: references adde