733 research outputs found

    Decays of the Meson BcB_c to a PP-Wave Charmonium State χc\chi_c or hch_c

    Full text link
    The semileptonic decays, Bc⟶χc(hc)+ℓ+νℓB_{c}{\longrightarrow}{\chi_c}(h_c)+{\ell}+{{\nu}}_{\ell}, and the two-body nonleptonic decays, Bc⟶χc(hc)+hB_{c}{\longrightarrow}{\chi_c}(h_c)+h, (here χc\chi_c and hch_c denote (ccˉ[3PJ])(c\bar c[^3P_J]) and (ccˉ[1P1])(c\bar c[^1P_1]) respectively, and hh indicates a meson) were computed. All of the form factors appearing in the relevant weak-current matrix elements with BcB_c as its initial state and a PP-wave charmonium state as its final state for the decays were precisely formulated in terms of two independent overlapping-integrations of the wave-functions of BcB_c and the PP-wave charmonium and with proper kinematics factors being `accompanied'. We found that the decays are quite sizable, so they may be accessible in Run-II at Tevatron and in the foreseen future at LHC, particularly, when BTeV and LHCB, the special detectors for B-physics, are borne in mind. In addition, we also pointed out that the decays Bc→hc+...B_c\to h_c+... may potentially be used as a fresh window to look for the hch_c charmonium state, and the cascade decays, Bc→χc[3P1,2]+l+νlB_c\to \chi_c[^3P_{1,2}]+l+\nu_l (Bc→χc[3P1,2]+hB_c\to \chi_c[^3P_{1,2}]+h) with one of the radiative decays χc[3P1,2]→J/ψ+γ\chi_c[^3P_{1,2}] \to J/\psi+\gamma being followed accordingly, may affect the observations of BcB_c meson through the decays Bc→J/ψ+l+νlB_{c}\to {J/\psi}+{l}+\nu_{l} (Bc→J/ψ+hB_c\to J/\psi+h) substantially.Comment: 24 pages, 3 figures, the replacement for improving the presentation and adding reference

    Solving the paradox of the folded falling chain by considering horizontal kinetic energy and link geometry

    Get PDF
    A folded chain, with one end fixed at the ceiling and the other end released from the same elevation, is commonly modeled as an energy-conserving system in one-dimension. However, the analytical paradigms in previous literature is unsatisfying: The theoretical prediction of the tension at the fixed end becomes infinitely large when the free end reaches the bottom, contradicting to the experimental observations. Furthermore, the dependence of the total falling time on the link number demonstrated in numerical simulations is still unexplained. Here, considering the horizontal kinetic energy and the geometry of each link, we derived analytical solutions of the maximal tension as well as the total falling time, in agreement with simulation results and experimental data reported in previous studies. This theoretical perspective shows a simple representation of the complicated two-dimensional falling chain system and, in particular, specifies the signature of the chain properties.Comment: 13 pages, 4 figure

    Single-Spin Measurement and Decoherence in Magnetic Resonance Force Microscopy

    Get PDF
    We consider a simple version of a cyclic adiabatic inversion (CAI) technique in magnetic resonance force microscopy (MRFM). We study the problem: What component of the spin is measured in the CAI MRFM? We show that the non-destructive detection of the cantilever vibrations provides a measurement of the spin component along the effective magnetic field. This result is based on numerical simulations of the Hamiltonian dynamics (the Schrodinger equation) and the numerical solution of the master equation.Comment: 5 pages + 5 figures (PNG format

    Critical Acceptance Factors of Cloud-Based Public Health Records

    Get PDF
    Personal health records (PHR) is a tool that can be used to assist patients in health management, and cloud-based PHR is expected to effectively integrate medical resources and information, elevate overall healthcare quality, and reduce unnecessary medical costs. This study tends to explore the factors that affect users’ intention to use with regard to the Microsoft HealthVault hybrid cloud health system in Taiwan. A research model combined with Unified Theory of Acceptance and Use of Technology (UTAUT) and Task-Technology Fit (TTF) models as well as perceived risks and trust is proposed including 10 hypotheses. After conducting a series survey, in total, 254 valid questionnaires in Taiwan were received. Some preliminary findings are discussed, and it is hoped that this model can be used to explore the key factors influencing usage intent toward the HealthVault

    Critical Factors of Adopting Enterprise Application Integration Technology: An Empirical Study on Larger Hospitals

    Get PDF
    As hospitals extend their service scope, they adopt more information systems. These systems are implemented in different timelines and the interfaces of databases become varied. Frequently, the exchange of information between various systems requires additional coordination or even manual input for unifying data. To embrace automation, the solution is to adopt enterprise application integration (EAI) technology, the middleware, to convert data from among various information systems to enable an efficient flow of data in the hospital. In this paper, we discuss and verify the impact factors on the integration levels of EAI by surveying larger hospitals above the regional level in Taiwan and testing a proposed research model. The findings of this study show that information technology infrastructure, hospital size, external pressure, internal pressure, and external support significantly affect the EAI level

    JCMT POL-2 and ALMA polarimetric observations of 6000-100 au scales in the protostar B335: linking magnetic field and gas kinematics in observations and MHD simulations

    Full text link
    We present our analysis of the magnetic field structures from 6000 au to 100 au scales in the Class 0 protostar B335 inferred from our JCMT POL-2 observations and the ALMA archival polarimetric data. To interpret the observational results, we perform a series of (non-)ideal MHD simulations of the collapse of a rotating non-turbulent dense core, whose initial conditions are adopted to be the same as observed in B335, and generate synthetic polarization maps. The comparison of our JCMT and simulation results suggests that the magnetic field on a 6000 au scale in B335 is pinched and well aligned with the bipolar outflow along the east-west direction. Among all our simulations, the ALMA polarimetric results are best explained with weak magnetic field models having an initial mass-to-flux ratio of 9.6. However, we find that with the weak magnetic field, the rotational velocity on a 100 au scale and the disk size in our simulations are larger than the observational estimates by a factor of several. An independent comparison of our simulations and the gas kinematics in B335 observed with the SMA and ALMA favors strong magnetic field models with an initial mass-to-flux ratio smaller than 4.8. We discuss two possibilities resulting in the different magnetic field strengths inferred from the polarimetric and molecular-line observations, (1) overestimated rotational-to-gravitational energy in B335 and (2) additional contributions in the polarized intensity due to scattering on a 100 au scale.Comment: Accepted by Ap

    A note on Zolotarev optimal rational approximation for the overlap Dirac operator

    Full text link
    We discuss the salient features of Zolotarev optimal rational approximation for the inverse square root function, in particular, for its applications in lattice QCD with overlap Dirac quark. The theoretical error bound for the matrix-vector multiplication Hw(Hw2)−1/2Y H_w (H_w^2)^{-1/2}Y is derived. We check that the error bound is always satisfied amply, for any QCD gauge configurations we have tested. An empirical formula for the error bound is determined, together with its numerical values (by evaluating elliptic functions) listed in Table 2 as well as plotted in Figure 3. Our results suggest that with Zolotarev approximation to (Hw2)−1/2 (H_w^2)^{-1/2} , one can practically preserve the exact chiral symmetry of the overlap Dirac operator to very high precision, for any gauge configurations on a finite lattice.Comment: 23 pages, 5 eps figures, v2:minor clarifications, and references added, to appear in Phys. Rev.

    Developing Particle Emission Inventories Using Remote Sensing (PEIRS)

    Get PDF
    Information regarding the magnitude and distribution of PM(sub 2.5) emissions is crucial in establishing effective PM regulations and assessing the associated risk to human health and the ecosystem. At present, emission data is obtained from measured or estimated emission factors of various source types. Collecting such information for every known source is costly and time consuming. For this reason, emission inventories are reported periodically and unknown or smaller sources are often omitted or aggregated at large spatial scale. To address these limitations, we have developed and evaluated a novel method that uses remote sensing data to construct spatially-resolved emission inventories for PM(sub 2.5). This approach enables us to account for all sources within a fixed area, which renders source classification unnecessary. We applied this method to predict emissions in the northeast United States during the period of 2002-2013 using high- resolution 1 km x 1 km Aerosol Optical Depth (AOD). Emission estimates moderately agreed with the EPA National Emission Inventory (R(sup2) = 0.66 approx. 0.71, CV = 17.7 approx. 20%). Predicted emissions are found to correlate with land use parameters suggesting that our method can capture emissions from land use-related sources. In addition, we distinguished small-scale intra-urban variation in emissions reflecting distribution of metropolitan sources. In essence, this study demonstrates the great potential of remote sensing data to predict particle source emissions cost-effectively
    • …
    corecore