2,275 research outputs found

    Implications of Muon anomalous magnetic moment for Direct detection of Neutralino Dark Matter

    Full text link
    We investigate the implications of the recent measurement of muon anomalous magnetic moment for the direct detection of neutralino dark matter in the three different SUSY models: mSUGRA, a model with non-universal Higgs mass, and an SO(10) GUT model. We consider two extreme scenario for Δaμ\Delta a_\mu bound, i.e. 27×1010<Δaμ<59×101027 \times 10^{-10} < \Delta a_\mu < 59 \times 10^{-10} (1σ\sigma bound) and 0<Δaμ<11×10100 < \Delta a_\mu < 11 \times 10^{-10} (2σ2\sigma below). In mSUGRA model, the counting ratio may be above the sensitivity of the future experiments when parameters are within 1σ1\sigma bound of Δaμ\Delta a_{\mu}. However, the Ωχ\Omega_{\chi} tends to be high compared to the currently favored value Ω=0.3\Omega=0.3. For models with the non-universal scalar masses, the possibility to have the consistent Ωχ\Omega_{\chi} and the high counting ratio is open up in the region of parameter space where Higgsino mass μ\mu is smaller than mSUGRA prediction. In particular, in the SO(10) model, the LSP dark matter detection rate may be enhanced by almost one order of magnitude compared to mSUGRA and the model with non-universal Higgs mass, for cosmologically acceptable Ωχh2\Omega_{\chi} h^2. The highest detection rate of LSP dark matter occurs in the region where the LSP constitutes a subdominant part of local halo DM. Implication of SUSY mass parameter measurement under the cosmological constraint is also discussed

    X-ray induced persistent photoconductivity in Si-doped Al0.35_{0.35}Ga0.65_{0.65}As

    Full text link
    We demonstrate that X-ray irradiation can be used to induce an insulator-metal transition in Si-doped Al0.35_{0.35}Ga0.65_{0.65}As, a semiconductor with {\it DX} centers. The excitation mechanism of the {\it DX} centers into their shallow donor state was revealed by studying the photoconductance along with fluorescence. The photoconductance as a function of incident X-ray energy exhibits an edge both at the Ga and As K-edge, implying that core-hole excitation of Ga and As are efficient primary steps for the excitation of {\it DX} centers. A high quantum yield (1\gg 1) suggests that the excitation is indirect and nonlocal, due to secondary electrons, holes, and fluorescence photons.Comment: 3 pages of text, 6 figures. An error in Fig.5 was detected, so we corrected i

    Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

    Get PDF
    In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

    Quantum State Discrimination with General Figures of Merit

    Full text link
    We solve the problem of quantum state discrimination with "general (symmetric) figures of merit" for an even number of symmetric quantum bits with use of the no-signaling principle. It turns out that conditional probability has the same form for any figure of merit. Optimal measurement and corresponding conditional probability are the same for any monotonous figure of merit.Comment: 5 pages, 2 figure

    Time dependent CP asymmetry in B0ρ0γB^0 \to \rho^0 \gamma decay to probe the origin of CP violation

    Full text link
    Since the CP violation in the BB system has been investigated up to now only through processes related to the BB--Bˉ\bar{B} mixing, urgently required is new way of study for the CP violation and establishing its origin in the BB system independent of the mixing process. In this work, we explore the exclusive B0ρ0γ B^0 \to \rho^0 \gamma decay to obtain the time-dependent CP asymmetry in bdb \to d decay process in the standard model and the supersymmetric model. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large CP asymmetry in bdγb \to d \gamma decay through the gluino-squark diagrams, which is not predicted in the Standard Model induced by the BB--Bˉ\bar{B} mixing.Comment: 10 pages, 4 eps figure

    A Newly Developed Web-Based Resource on Genetic Eye Disorders for Users With Visual Impairment (Gene.Vision): Usability Study

    Get PDF
    Background: Despite the introduction of the Web Content Accessibility Guidelines and legislations, many websites remain poorly accessible to users with disability, especially those with visual impairment, as the internet has become a more visually complex environment. With increasing reliance on the internet and almost 2 million people in the United Kingdom being affected by vision loss, it is important that they are not overlooked when developing web-based materials. A significant proportion of those affected have irreversible vision loss due to rare genetic eye disorders, and many of them use the internet as a primary source of information for their conditions. However, access to high-quality web-based health information with an inclusive design remains a challenge for many. We have developed a new web-based resource for genetic eye disorders called Gene.Vision that aims to provide a holistic guide for patients, relatives, and health care professionals. Objective: Through a usability testing session of our website prototype, this study aims to identify key web-based accessibility features for internet users with vision impairment and to explore whether the contents provided in Gene.Vision are relevant and comprehensible. Methods: A face-to-face testing session with 8 participants (5 patients, 2 family members, and 1 member of the public) and 8 facilitators was conducted on a prototype website. Remote testing was performed with another patient due to COVID-19 restrictions. Home page design, navigation, content layout and quality, language, and readability were explored through direct observation and task completion using the think-aloud method. A patient focus group was organized to elicit further feedback. Qualitative data were gathered and analyzed to identify core themes through open and axial coding. Results: All participants had good computer literacy; 6 patients with visual impairment used visual aid software including iOS VoiceOver and Speak Screen, iOS Classic Invert, ZoomText 2020, Job Access With Speech, and Nonvisual Desktop Access. The features identified by the participants that will enhance accessibility and usability for users with visual impairment were a consistent website layout, a structured information hierarchy with a clear description of links, good chromatic and luminance contrast, a simple home page with predictable and easy navigation, adaptability to various assistive software, and readable and relevant content. They reported that dynamic content (such as carousels) and large empty spaces reduced accessibility. Information on research, support available, practical advice, and links to charities were incentives for repeated website visits. Conclusions: We demonstrated the importance of developing a website with a user-based approach. Through end user testing, we identified several key web-based accessibility features for people with visual impairment. Target end users should always be involved early and throughout the design process to ensure their needs are met. Many of these steps can be implemented easily and will aid in search engine optimization

    Exactly solvable charged dilaton gravity theories in two dimensions

    Get PDF
    We find exactly solvable dilaton gravity theories containing a U(1) gauge field in two dimensional space-time. The classical general solutions for the gravity sector (the metric plus the dilaton field) of the theories coupled to a massless complex scalar field are obtained in terms of the stress-energy tensor and the U(1) current of the scalar field. We discuss issues that arise when we attempt to use these models for the study of the gravitational back-reaction.Comment: The introductory part is changed. a version to appear in Class. Quant. Grav. 6 pages, RevTe
    corecore