7,210 research outputs found

    Next-to-leading order renormalization of the ΔB=2\Delta B=2 operators in the static theory

    Full text link
    The renormalization, at the next-to-leading order in αs\alpha_s, of the ΔB=2\Delta B=2 operators at the lowest order in the heavy quark expansion, namely in the static theory, is computed taking into account previously missed contributions. These operators are relevant for the calculation of the B0B^0--Bˉ0\bar B^0 mixing on the lattice.Comment: Latex, 8 pages, 1 figur

    The Mass of the Convective Zone in FGK Main Sequence Stars and the Effect of Accreted Planetary Material on Apparent Metallicity Determinations

    Get PDF
    The mass of the outer convective zone in FGK main sequence stars decreases dramatically with stellar mass. Therefore, any contamination of a star's atmosphere by accreted planetary material should affect hotter stars much more than cool stars. If recent suggestions that high metal abundances in stars with planets are caused by planetesimal accretion are correct, then metallicity enhancements in earlier-type stars with planets should be very pronounced. No such trend is seen, however.Comment: Submitted ApJ Letters March 26th; accepted April 30th. 12 pages, 2 figure

    Delta M_K and epsilon_K in SUSY at the Next-to-Leading order

    Full text link
    We perform a Next-to-Leading order analysis of Delta S=2 processes beyond the Standard Model. Combining the recently computed NLO anomalous dimensions and the B parameters of the most general Delta S=2 effective Hamiltonian, we give an analytic formula for Delta M_K and epsilon_K in terms of the Wilson coefficients at the high energy scale. This expression can be used for any extension of the Standard Model with new heavy particles. Using this result, we consider gluino-mediated contributions to Delta S=2 transitions in general SUSY models and provide an improved analysis of the constraints on off-diagonal mass terms between the first two generations of down-type squarks. Finally, we improve the constraints on R-violating couplings from Delta M_K and epsilon_K.Comment: 20 pages, 1 figure, uses JHEP.cls; the magic numbers in eq. (2.7), previously given in the basis (13) of hep-ph/9711402, are now given in the basis (2.3) of this work. All numerical results are unchange

    Improved reproductive response of sheep in intrauterine insemination program with the use of royal jelly

    Get PDF
    The objective of the present study was to evaluate estrus and conception rates obtained with the use of progesterone (P4) cream in intravaginal sponges in conjunction with equine chorionic gonadotropin (eCG) or eCG plus royal jelly (RJ) given at the time of sponge withdrawal. A total of 365 fat tailed ewes were assigned randomly to two treatment groups: insertion of intravaginal sponge containing 30 mg (LNP; n = 188) or 60 mg (HNP; n = 177) progesterone for 12 days. For each treatment, 300 or 600 IU of eCG were compared with 100 or 300 IU of eCG plus 500 mg of RJ to assess the effect on reproductive parameters of ewes inseminated laparoscopically in the anoestrus season. Ewes in each group were inseminated with fresh diluted semen (10 × 107 sperm per insemination dose). Inseminations were carried out 11 to 18 h after the first detection of estrus. Pregnancy diagnosis was done at approximately 55 days after insemination. For the 30 and 60 mg natural progesterone treated groups, estrous (22.3 versus 30.5%) and conception rates (50.0% for both treatments) did not differ significantly. Ewes that received 300 IU eCG plus 500 mg RJ had higher (P>0.05) conception rates (66.7 versus 47.6 and 40.0%) than those treated with only eCG (300 or 600 IU) at sponge removal. There was a significant (P≤0.05) delay in onset of estrus in ewes treated with 100 IU eCG plus 500 mg RJ when compared with the other treatment groups.Keywords: Royal jelly, equine chorionic gonadotropin (eCG), natural progesterone, artificial insemination, ew

    Model independent determination of the shape function for inclusive B decays and of the structure functions in DIS

    Get PDF
    We present a method to compute, by numerical simulations of lattice QCD, the inclusive semileptonic differential decay rates of heavy hadrons and the structure functions which occur in deep inelastic scattering. The method is based on first principles and does not require any model assumption. It allows the prediction of the differential rate in B semileptonic decays for values of the recoiling hadronic mass W ~ sqrt(M_B Lambda_QCD), which is in the relevant region to extract |V_ub| from the end-point of the lepton spectrum in inclusive decays.Comment: 16 pages, LaTeX fil

    Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams

    Get PDF
    hree-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55μm pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0±0.5% is measured. After a 10o rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises to 99.8±0.5%. The double-sided 3D sensor shows significantly reduced charge sharing to neighbouring pixels compared to the planar device. The charge sharing results obtained from the X-ray beam study of the 3D sensor are shown to agree with a simple simulation in which charge diffusion is neglected. The devices tested are found to be compatible with having a region in which no charge is collected centred on the electrode columns and of radius 7.6±0.6μm. Charge collection above and below the columnar electrodes in the double-sided 3D sensor is observed

    New evidence about the subduction of the Copiap\uf2 ridge beneath South America, and its connection with the Chilean-Pampean flat slab, tracked by satellite GOCE and EGM2008 models

    Get PDF
    Satellite-only gravity measurements and those integrated with terrestrial observations provide global gravity field models of unprecedented precision and spatial resolution, which allow analyzing lithospheric structure allowing the analysis of the lithospheric structure. We used the model EGM2008 (Earth Gravitational Model) to calculate the gravity anomaly and the vertical gravity gradient in the South Central Andes region, correcting these quantities by the topographic effect. Both quantities show a spatial relationship between the projected subduction of the Copiap\uf3 aseismic ridge (located at 33 about 27\uba 30\u2019 S), its potential deformational effects in the overriding plate, and the Ojos del Salado-San Buenaventura volcanic lineament. This volcanic lineament constitutes a projection of the volcanic arc towards the retroarc zone, whose origin and development were not clearly understood. The analysis of the gravity anomalies, at the extrapolated zone of the Copiap\uf3 ridge beneath the continent, shows a change in the general NNE38 trend of the Andean structures to an ENE-direction coincident with the area of the Ojos del Salado-San Buenaventura volcanic lineament. This anomalous pattern over the upper plate is interpreted to be linked with the subduction of the Copiap\uf3 ridge. We explore the relation between deformational effects and volcanism at the northern Chilean-Pampean flat slab and the collision of the Copiap\uf3 ridge, on the basis of the Moho geometry and elastic thicknesses calculated from the new satellite GOCE data. Neotectonic deformations interpreted in previous works associated with volcanic eruptions along the Ojos del Salado-San Buenaventura volcanic lineament is interpreted as caused by crustal doming, imprinted by the subduction of the Copiap\uf3 ridge, evidenced by crustal thickening at the sites of ridge inception along the trench. Finally, we propose that the Copiap\uf3 ridge could have controlled the northern edge of the Chilean-Pampean flat slab, due to higher buoyancy, similarly to the control that the Juan Fernandez ridge exerts in the geometry of the flat slab further south

    Evaluation of crowdsourcing Wi-Fi radio map creation in a real scenario for AAL applications

    Get PDF
    Indoor location at room level plays a key role for providing useful services for Ambient Assisted Living (AAL) applications. Wi-Fi fingerprinting indoor location methods are extensively used due to the widespread availability of WiFi infrastructures. A main drawback of Wi-Fi fingerprinting methods is the temporal cost involved in creating the radio maps. Crowdsourcing strategies have been presented as a way to minimize the cost of radio map creation. In this work, we present an extensive study of the issues involved when using crowdsourcing strategies for that purpose. Results provided by extensive experiments performed in a real scenario by three users during two weeks are presented. The main conclusions are: i) crowdsourcing data improves accuracy location in most studied cases; ii) accuracy of Wi-Fi fingerprinting methods decay along time; iii) device diversity is an important issue even when using the same device model

    B-physics computations from Nf=2 tmQCD

    Get PDF
    We present an accurate lattice QCD computation of the b-quark mass, the B and Bs decay constants, the B-mixing bag-parameters for the full four-fermion operator basis, as well as estimates for \xi and f_{Bq}\sqrt{B_q} extrapolated to the continuum limit and the physical pion mass. We have used Nf = 2 dynamical quark gauge configurations at four values of the lattice spacing generated by ETMC. Extrapolation in the heavy quark mass from the charm to the bottom quark region has been carried out using ratios of physical quantities computed at nearby quark masses, having an exactly known infinite mass limit.Comment: 7 pages, 4 figures, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German
    • …
    corecore