1,720,965 research outputs found

    Hadronic light-by-light contribution to the muon anomalous magnetic moment from lattice QCD

    Full text link
    We report preliminary results for the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment. Several ensembles using 2+1 flavors of M\"obius domain-wall fermions, generated by the RBC/UKQCD collaborations, are employed to take the continuum and infinite volume limits of finite volume lattice QED+QCD. We find $a_\mu^{\rm HLbL} = (7.41\pm6.33)\times 10^{-10}

    Progress in the improved lattice calculation of direct CP-violation in the Standard Model

    Full text link
    We discuss the ongoing effort by the RBC & UKQCD collaborations to improve our lattice calculation of the measure of Standard Model direct CP violation, ∊’, with physical kinematics. We present our progress in decreasing the (dominant) statistical error and discuss other related activities aimed at reducing the systematic errors

    The KL - KS Mass Difference

    No full text
    We review the status of the RBC-UKQCD collaborations’ computations of the KL-KS mass difference. After a brief discussion of the theoretical framework which had been developed previously by the collaboration, we describe our latest computation, performed at physical quark masses, and present our preliminary result mKL - mKS = (5.5 ± 1.70) × 10-12 MeV

    The K<sub>L</sub> - K<sub>S</sub> mass difference

    No full text
    We review the status of the RBC-UKQCD collaborations' computations of the KL-KS mass difference. After a brief discussion of the theoretical framework which had been developed previously by the collaboration, we describe our latest computation, performed at physical quark masses, and present our preliminary result mKL - mKS = (5.5 ± 1.70) × 10-12 MeV.</p

    Direct CP violation and the Δ

    No full text
    We discuss the RBC & UKQCD collaborations’ recent [1] lattice calculation of ϵ′, the measure of direct CP-violation in kaon decays. This result significantly improves on our previous 2015 calculation, with nearly 4× the statistics and more reliable systematic error estimates. We discuss how our results demonstrate the Standard Model origin of the ΔI = 1/2 rule, and present our plans for future calculations

    Hadronic light-by-light contribution to the muon anomaly from lattice QCD with infinite volume QED at physical pion mass

    Full text link
    The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment, (g2(g-2)/2, is computed in the infinite volume QED framework with lattice QCD. We report aμHLbL=12.47(1.15)(0.95)×1010a_μ^\text{HLbL}=12.47(1.15)(0.95) \times 10^{-10} where the first error is statistical and the second systematic. The result is mainly based on the 2+1 flavor Möbius domain wall fermion ensemble with inverse lattice spacing a1=1.73 GeVa^{-1} = 1.73~\mathrm{GeV}, lattice size L=5.5 fmL=5.5~\mathrm{fm}, and mπ=139 MeVm_π= 139~\mathrm{MeV}, generated by the RBC-UKQCD collaborations. The leading systematic error of this result comes from the lattice discretization. This result is consistent with previous determinations.29 page

    Exploring interpolating momentum schemes

    Full text link
    We compute the renormalisation factors of the quark mass and wave function using IMOM (Interpolating MOMenta) schemes. The framework is the Rome-Southampton non-renormalisation method, but the momentum transfer in the quark bilinears is not restricted to zero or to the symmetric point. We study the scale dependence, infrared contamination and lattice artefacts for different values of this momentum transfer and for two different kinds of projectors. For the numerical simulations, we use data generated by the RBC-UKQCD collaborations, with Nf = 2 + 1 flavours of Domain-Wall fermions, and inverse lattice spacing of 1.79 and 2.38 GeV

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

    Full text link
    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
    corecore