130,310 research outputs found

    DsJ(2860)D_{sJ}(2860) and DsJ(2715)D_{sJ}(2715)

    Full text link
    Recently Babar Collaboration reported a new csˉc\bar{s} state DsJ(2860)D_{sJ}(2860) and Belle Collaboration observed DsJ(2715)D_{sJ}(2715). We investigate the strong decays of the excited csˉc\bar{s} states using the 3P0^{3}P_{0} model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we tend to conclude: (1) DsJ(2715)D_{sJ}(2715) is probably the 1(13D1)1^{-}(1^{3}D_{1}) csˉc\bar{s} state although the 1(23S1)1^{-}(2^{3}S_{1}) assignment is not completely excluded; (2) DsJ(2860)D_{sJ}(2860) seems unlikely to be the 1(23S1)1^{-}(2^{3}S_{1}) and 1(13D1)1^{-}(1^{3}D_{1}) candidate; (3) DsJ(2860)D_{sJ}(2860) as either a 0+(23P0)0^{+}(2^{3}P_{0}) or 3(13D3)3^{-}(1^{3}D_{3}) csˉc\bar{s} state is consistent with the experimental data; (4) experimental search of DsJ(2860)D_{sJ}(2860) in the channels DsηD_s\eta, DKDK^{*}, DKD^{*}K and DsηD_{s}^{*}\eta will be crucial to distinguish the above two possibilities.Comment: 18 pages, 7 figures, 2 tables. Some discussions added. The final version to appear at EPJ

    Frequency shift up to the 2-PM approximation

    Full text link
    A lot of fundamental tests of gravitational theories rely on highly precise measurements of the travel time and/or the frequency shift of electromagnetic signals propagating through the gravitational field of the Solar System. In practically all of the previous studies, the explicit expressions of such travel times and frequency shifts as predicted by various metric theories of gravity are derived from an integration of the null geodesic differential equations. However, the solution of the geodesic equations requires heavy calculations when one has to take into account the presence of mass multipoles in the gravitational field or the tidal effects due to the planetary motions, and the calculations become quite complicated in the post-post-Minkowskian approximation. This difficult task can be avoided using the time transfer function's formalism. We present here our last advances in the formulation of the one-way frequency shift using this formalism up to the post-post-Minkowskian approximation.Comment: 4 pages, submitted to proceedings of SF2

    Relativistic formulation of coordinate light time, Doppler and astrometric observables up to the second post-Minkowskian order

    Full text link
    Given the extreme accuracy of modern space science, a precise relativistic modeling of observations is required. In particular, it is important to describe properly light propagation through the Solar System. For two decades, several modeling efforts based on the solution of the null geodesic equations have been proposed but they are mainly valid only for the first order Post-Newtonian approximation. However, with the increasing precision of ongoing space missions as Gaia, GAME, BepiColombo, JUNO or JUICE, we know that some corrections up to the second order have to be taken into account for future experiments. We present a procedure to compute the relativistic coordinate time delay, Doppler and astrometric observables avoiding the integration of the null geodesic equation. This is possible using the Time Transfer Function formalism, a powerful tool providing key quantities such as the time of flight of a light signal between two point-events and the tangent vector to its null-geodesic. Indeed we show how to compute the Time Transfer Functions and their derivatives (and thus range, Doppler and astrometric observables) up to the second post-Minkowskian order. We express these quantities as quadratures of some functions that depend only on the metric and its derivatives evaluated along a Minkowskian straight line. This method is particularly well adapted for numerical estimations. As an illustration, we provide explicit expressions in static and spherically symmetric space-time up to second post-Minkowskian order. Then we give the order of magnitude of these corrections for the range/Doppler on the BepiColombo mission and for astrometry in a GAME-like observation.Comment: 22 pages, 5 figures, accepted in Phys. Rev.

    Light propagation in the field of a moving axisymmetric body: theory and application to JUNO

    Full text link
    Given the extreme accuracy of modern space science, a precise relativistic modeling of observations is required. We use the Time Transfer Functions formalism to study light propagation in the field of uniformly moving axisymmetric bodies, which extends the field of application of previous works. We first present a space-time metric adapted to describe the geometry of an ensemble of uniformly moving bodies. Then, we show that the expression of the Time Transfer Functions in the field of a uniformly moving body can be easily derived from its well-known expression in a stationary field by using a change of variables. We also give a general expression of the Time Transfer Function in the case of an ensemble of arbitrarily moving point masses. This result is given in the form of an integral easily computable numerically. We also provide the derivatives of the Time Transfer Function in this case, which are mandatory to compute Doppler and astrometric observables. We particularize our results in the case of moving axisymmetric bodies. Finally, we apply our results to study the different relativistic contributions to the range and Doppler tracking for the JUNO mission in the Jovian system.Comment: 17 pages, 4 figures, submitted to Phys. Rev. D, some corrections after revie

    CKM Matrix: Status and New Developments

    Full text link
    An analysis of the CKM matrix parameters within the {\it R}fit approach is presented using updated input values with special emphasis on the recent sin2β\sin{2\beta} measurements from BABAR and Belle. The QCD Factorisation Approach describing Bππ,KπB \to \pi\pi,K\pi decays has been implemented in the software package CKMfitter. Fits using branching ratios and CP asymmetries are discussed.Comment: 5 pages, 6 postscript figures, contribution to the proceedings of the 9th International Symposium on Heavy Flavour Physics, September 2001, Pasadena, US

    A New Approach to a Global Fit of the CKM Matrix

    Full text link
    We report on a global CKM matrix analysis taking into account most recent experimental and theoretical results. The statistical framework (Rfit) developed in this paper advocates formal frequentist statistics. Other approaches, such as Bayesian statistics or the 95% CL scan method are also discussed. We emphasize the distinction of a model testing and a model dependent, metrological phase in which the various parameters of the theory are determined. Measurements and theoretical parameters entering the global fit are thoroughly discussed, in particular with respect to their theoretical uncertainties. Graphical results for confidence levels are drawn in various one and two-dimensional parameter spaces. Numerical results are provided for all relevant CKM parameterizations, the CKM elements and theoretical input parameters. Predictions for branching ratios of rare K and B meson decays are obtained. A simple, predictive SUSY extension of the Standard Model is discussed.Comment: 66 pages, added figures, corrected typos, no quantitative change

    The impact of motor symptoms on self-reported anxiety in Parkinson's disease

    Get PDF
    OBJECTIVE: Anxiety is commonly endorsed in Parkinson's disease (PD) and significantly affects quality of life. The Beck Anxiety Inventory (BAI) is often used but contains items that overlap with common PD motor symptoms (e.g., “hands trembling”). Because of these overlapping items, we hypothesized that PD motor symptoms would significantly affect BAI scores. METHODS: One hundred non-demented individuals with PD and 74 healthy control participants completed the BAI. PD motor symptoms were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). Factor analysis of the BAI assessed for a PD motor factor, and further analyses assessed how this factor affected BAI scores. RESULTS: BAI scores were significantly higher for PD than NC. A five-item PD motor factor correlated with UPDRS observer-rated motor severity and mediated the PD-control difference on BAI total scores. An interaction occurred, whereby removal of the PD motor factor resulted in a significant reduction in BAI scores for PD relative to NC. The correlation between the BAI and UPDRS significantly declined when controlling for the PD motor factor. CONCLUSIONS: The results indicate that commonly endorsed BAI items may reflect motor symptoms such as tremor instead of, or in addition to, genuine mood symptoms. These findings highlight the importance of considering motor symptoms in the assessment of anxiety in PD and point to the need for selecting anxiety measures that are less subject to contamination by the motor effects of movement disorders.Published versio

    The effect of an imaginary part of the Schwinger-Dyson equation at finite temperature and density

    Full text link
    We examined the effect of an imaginary part of the ladder approximation Schwinger-Dyson equation. We show the imaginary part enhances the effect of the first order transition, and affects a tricritical point. In particular, a chemical potential at a tricritical point is moved about 200(MeV). Thus, one should not ignore the imaginary part. On the other hand, since an imaginary part is small away from a tricritical point, one should be able to ignore an imaginary part. In addition, we also examined the contribution of the wave function renormalization constant.Comment: 12 pages, 14 figure

    Combining high pressure and coherent diffraction: a first feasibility test

    Full text link
    We present a first experiment combining high pression and coherent X-ray diffraction. By using a dedicated diamond anvil cell, we show that the degree of coherence of the X-ray beam is preserved when the X-ray beam passes through the diamond cell. This observation opens the possibility of studying the dynamics of slow fluctuations under high pressure.Comment: 3 pages, 2 figures, GHPR 2009 conferenc

    Relativistic dynamical polarizability of hydrogen-like atoms

    Full text link
    Using the operator representation of the Dirac Coulomb Green function the analytical method in perturbation theory is employed in obtaining solutions of the Dirac equation for a hydrogen-like atom in a time-dependent electric field. The relativistic dynamical polarizability of hydrogen-like atoms is calculated and analysed.Comment: 15 pages, 3 figures (not included, but hard copies are available upon request
    corecore