A New Class of Solutions to the Strong CP Problem with a Small Two-Loop theta

We present a new class of models which produce zero theta (QCD} angle at the tree and one-loop level due to hermiticity of sub-blocks in the extended quark mass matrices. The structure can be maintained typically by non-abelian generation symmetry. Two examples are given for this class of solutions.Comment: 4 pages, 2 figure

Community Internet of Things as Mobile Infrastructure: Methodological Challenges and Opportunities

From smart devices to homes to cities, Internet of Things (IoT) technologies have become embedded within everyday objects on a global scale. We understand IoT technologies as a form of infrastructure that bridges the gaps between offline spaces and online networks as they track, transmit, and construct digital data from and of the physical world. We examine the social construction of IoT network technologies through their technological design and corporate discourses. In this article, we explore the methodological challenges and opportunities of studying IoT as an emerging network technology. We draw on a case study of a low-power wide-area network (LPWAN), a cost-effective radio frequency network that is designed to connect sensors across long distances. Reflecting on our semi-structured interviews with LPWAN users and advocates, participant observation at conferences about LPWAN, as well as a community-based LPWAN project, we examine the intersections of methods and practices as related to space, data, and infrastructures. We identify three key methodological obstacles involved in studying the social construction of networked technologies that straddle physical and digital environments. These include (a) transcending the invisibility and abstraction of network infrastructures, (b) managing practical and conceptual boundaries to sample key cases and participants, and (c) negotiating competing technospatial imaginaries between participants and researchers. Through our reflection, we demonstrate that these challenges also serve as generative methodological opportunities, extending existing tools to study the ways data connects online and offline spaces

Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model

A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations

Relativistic Effects in S-Wave Quarkonium Decay

The decay widths of S-wave quarkonia (\etc,\etb\to \gg{~~and~~} \J,\U\to\ee) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via quarkonium wave function. It is shown that relativistic corrections may be large (10-50 %) and comparable with QCD corrections.Comment: 10 pages, no figure

High energy neutrinos from neutralino annihilations in the Sun

Neutralino annihilations in the Sun to weak boson and top quark pairs lead to high-energy neutrinos that can be detected by the IceCube and KM3 experiments in the search for neutralino dark matter. We calculate the neutrino signals from real and virtual WW, ZZ, Zh, and $t \bar t$ production and decays, accounting for the spin-dependences of the matrix elements, which can have important influences on the neutrino energy spectra. We take into account neutrino propagation including neutrino oscillations, matter-resonance, absorption, and nu_tau regeneration effects in the Sun and evaluate the neutrino flux at the Earth. We concentrate on the compelling Focus Point (FP) region of the supergravity model that reproduces the observed dark matter relic density. For the FP region, the lightest neutralino has a large bino-higgsino mixture that leads to a high neutrino flux and the spin-dependent neutralino capture rate in the Sun is enhanced by 10^3 over the spin-independent rate. For the standard estimate of neutralino captures, the muon signal rates in IceCube are identifiable over the atmospheric neutrino background for neutralino masses above M_Z up to 400 GeV.Comment: 45 pages, 18 figures and 5 tables, PRD versio

Galerkin FEM for fractional order parabolic equations with initial data in H−s, 0<s≤1H^{-s},~0 < s \le 1

We investigate semi-discrete numerical schemes based on the standard Galerkin and lumped mass Galerkin finite element methods for an initial-boundary value problem for homogeneous fractional diffusion problems with non-smooth initial data. We assume that $\Omega\subset \mathbb{R}^d$, $d=1,2,3$ is a convex polygonal (polyhedral) domain. We theoretically justify optimal order error estimates in $L_2$- and $H^1$-norms for initial data in $H^{-s}(\Omega),~0\le s \le 1$. We confirm our theoretical findings with a number of numerical tests that include initial data $v$ being a Dirac $\delta$-function supported on a $(d-1)$-dimensional manifold.Comment: 13 pages, 3 figure

More Signatures of the Intermediate Mass Higgs Boson

We examine the potential signatures of the Higgs boson when it decays into a tau-lepton pair. We show that with the proper identification of the tau-jet, this decay mode can lead to the identification of the Higgs boson over most of the intermediate mass range (\mW $<$ \mH $<$ 2 \mW).Comment: 10 pages, LaTeX fil

Relativistic and Binding Energy Corrections to Direct Photon Production In Upsilon Decay

A systematic gauge-invariant method is used to calculate the rate for an upsilon meson to decay inclusively into a prompt photon. An expansion is made in the quark relative velocity v, which is a small natural parameter for heavy quark systems. Inclusion of these O(v^2) corrections tends to increase the photon rate in the middle z range and to lower it for larger z, a feature supported by the data.Comment: 13 pages, LateX, One figure (to be published in Phys. Rev. D, Sept. 1, 1996

Theoretical investigation of positional influence of FBG sensors for structural health monitoring of offshore structures.

Fibre Bragg Grating (FBG) is a key technology for condition monitoring of different offshore oil and gas structures. FBG sensors are used to sense different physical parameters such as strain, temperature, vibration, etc. This paper investigates the effect of FBG sensor positions on the reflected sensing signal, to optimise the sensor positioning plan for structural health monitoring of offshore structures. Theoretical investigations were carried out on a cantilever beam to analyze the strain effects. Effect of different cantilever beam shapes, materials and their thickness on strain was investigated. Theoretical studies were also carried out to evaluate the strain sensitivities of FBG sensors. Furthermore, micrometer displacement based strain analysis of cantilever beam was carried out using FBG sensors and electrical strain gauges to study the positional influence and compared it with the theoretical results obtained