Top and Bottom Squarks Decays under Cosmological Bounds

We investigate the fermionic decays of top squarks tilde t_{1,2} and bottom squarks tilde b_{1,2}$ in the Minimal Supersymmetric Standard Model with complex parameters M_1, mu, A_t and A_b . In the analysis we particularly take into account the cosmological bounds imposed by WMAP data. We plot the CP phase dependences of stop and sbottom decay widths.Comment: 1 text(9 pages)and 8 figures(6 pages). Total 15 pages. Accepted to be published in Phys.Lett.

The effect of supersymmetric CP phases on Chargino-Pair Production via Drell-Yan Process at the LHC

We compute the rates for pp annihilation into chargino-pairs via Drell-Yan process taking into account the effects of supersymmetric soft phases, at proton-proton collider. In particular, the phase of the mu parameter gains direct accessibility via the production of dissimilar charginos. The phases of the trilinear soft masses do not have a significant effect on the cross sections.Comment: 24 pages, 7 figure

Electroweak Breaking and the mu problem in Supergravity Models with an Additional U(1)

We consider electroweak symmetry breaking in supersymmetric models with an extra non-anomalous U(1)' gauge symmetry and an extra standard-model singlet scalar S. For appropriate charges the U(1)' forbids an elementary mu term, but an effective mu is generated by the VEV of S, leading to a natural solution to the mu problem. There are a variety of scenarios leading to acceptably small Z-Z' mixing and other phenomenological consequences, all of which involve some but not excessive fine tuning. One class, driven by a large trilinear soft supersymmetry breaking term, implies small mixing, a light Z' (e.g., 200 GeV), and an electroweak phase transition that may be first order at tree level. In another class, with m_S^2 < 0 (radiative breaking), the typical scale of dimensional parameters, including M_{Z'} and the effective mu, is O(1 TeV), but the electroweak scale is smaller due to cancellations. We relate the soft supersymmetry breaking parameters at the electroweak scale to those at the string scale, choosing Yukawa couplings as determined within a class of string models. We find that one does not obtain either scenario for universal soft supersymmetry breaking mass parameters at the string scale and no exotic multiplets contributing to the renormalization group equations. However, either scenario is possible when the assumption of universal soft breaking is relaxed. Radiative breaking can also be generated by exotics, which are expected in most string models.Comment: 45 pages, revtex, 20 eps figures, psfig.sty; Minor numerical renormalization group results corrected. Erratum to appear in Phys. Rev.

Systems Biology Graphical Notation: Process Description language Level 1

Standard graphical representations have played a crucial role in science and engineering throughout the last century. Without electrical symbolism, it is very likely that our industrial society would not have evolved at the same pace. Similarly, specialised notations such as the Feynmann notation or the process flow diagrams did a lot for the adoption of concepts in their own fields. With the advent of Systems Biology, and more recently of Synthetic Biology, the need for precise and unambiguous descriptions of biochemical interactions has become more pressing. While some ideas have been advanced over the last decade, with a few detailed proposals, no actual community standard has emerged. The Systems Biology Graphical Notation (SBGN) is a graphical representation crafted over several years by a community of biochemists, modellers and computer scientists. Three orthogonal and complementary languages have been created, the Process Diagrams, the Entity Relationship Diagrams and the Activity Flow Diagrams. Using these three idioms a scientist can represent any network of biochemical interactions, which can then be interpreted in an unambiguous way. The set of symbols used is limited, and the grammar quite simple, to allow its usage in textbooks and its teaching directly in high schools. The first level of the SBGN Process Diagram has been publicly released. Software support for SBGN Process Diagram was developed concurrently with its specification in order to speed-up public adoption. Shared by the communities of biochemists, genomicians, theoreticians and computational biologists, SBGN languages will foster efficient storage, exchange and reuse of information on signalling pathways, metabolic networks and gene regulatory maps

Sneutrino Dark Matter: Symmetry Protection and Cosmic Ray Anomalies

We present an R-parity conserving model of sneutrino dark matter within a Higgs-philic U(1)' extension of the minimal supersymmetric standard model. In this theory, the mu parameter and light Dirac neutrino masses are generated naturally upon the breaking of the U(1)' gauge symmetry. The leptonic and hadronic decays of sneutrinos in this model, taken to be the lightest and next-to-lightest superpartners, allow for a natural fit to the recent results reported by the PAMELA experiment.Comment: Revised to match the published version; 11 pages (2 column format), 1 table, 6 figures, to appear in PR

After-body liner performance predictions on bypass exhaust fan noise with a simple 3/4 cowl geometry and coaxial mean flow

Aft fan noise is becoming a more dominant source as engine bypass ratio is increased and improved methods are required for its control. Bypass liners are especially effective in attenuating aft fan noise, but, in recent papers we introduced the idea of using acoustic linings on external parts of the aero-engine nacelle, such as the afterbody and plug nozzle. We showed that when the afterbody is acoustically lined, it can reduces the far field broadband sound power by up to 3 dB in the absence of flow, an experimental result which was confirmed with calculations using a commercially available CAA code. In this paper, we extend the previous computations to include the effects of a two-stream coaxial flow using the same CAA code but with a new 1D membrane element to represent the shear layers. The results, supported by two analytical models, confirm our expectations that the AL could also provide significant reductions in aft fan with flow. As anticipated the main flow effect is to refract the no-flow insertion loss to larger angles outside the cone of silence, with little or no benefits inside the cone of silence. However, it should be emphasised that although the results obtained so far are with a representative mean flow, the geometry is still idealized and these and other computations have to be validated with data from large-scale tests based on a fully realistic geometry and flow

Relaxation of the Dynamical Gluino Phase and Unambiguous Electric Dipole Moments

We propose a new axionic solution of the strong CP problem with a Peccei-Quinn mechanism using the gluino rather than quarks. The spontaneous breaking of this new global U(1) at 10^{11} GeV also generates the supersymmetry breaking scale of 1 TeV (solving the so-called \mu problem at the same time) and results in the MSSM (Minimal Supersymmetric Standard Model) with R parity conservation. In this framework, electric dipole moments become calculable without ambiguity.Comment: Typos corrected and a footnote added, 10 p

Dirac Neutrino Masses from Generalized Supersymmetry Breaking

We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector. If the usual superpotential Yukawa couplings are forbidden by the additional gauge symmetry (such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field can arise either at tree level due to hard supersymmetry breaking fermion Yukawa couplings, or at one-loop due to nonanalytic or "nonholomorphic" soft supersymmetry breaking trilinear scalar couplings. As both of these operators are naturally suppressed in generic models of supersymmetry breaking, the resulting neutrino masses are naturally in the sub-eV range. The neutrino magnetic and electric dipole moments resulting from the radiative mechanism also vanish at one-loop order.Comment: 5 pages, 1 figure, references added, note added on effective superpotential mass terms generated upon U(1)' breakin

On the Coulomb-Sturmian matrix elements of the Coulomb Green's operator

The two-body Coulomb Hamiltonian, when calculated in Coulomb-Sturmian basis, has an infinite symmetric tridiagonal form, also known as Jacobi matrix form. This Jacobi matrix structure involves a continued fraction representation for the inverse of the Green's matrix. The continued fraction can be transformed to a ratio of two $_{2}F_{1}$ hypergeometric functions. From this result we find an exact analytic formula for the matrix elements of the Green's operator of the Coulomb Hamiltonian.Comment: 8 page