1,720,971 research outputs found
Inclusive semi-leptonic decays of charmed mesons with Möbius domain wall fermions
No full textWe perform a non-perturbative lattice calculation of the decay rates for inclusive semi-leptonic decays of charmed mesons. In view of the long-standing tension in the determination of the CKM matrix elements |Vub| and |Vcb| from exclusive and inclusive processes, recently, the use of lattice QCD has been extended towards the description of inclusive decays. Since the determination of hadronic input parameters from QCD based methods require independent tests, we focus on the charm sector, since it not only offers experimental data, but also well determined CKM parameters. We carry out a pilot lattice simulation for the Ds→Xsℓν and explore the improvement of existing techniques. Our simulation employs Möbius domain-wall charm and strange quarks whose masses are tuned to be approximately physical and we cover the whole kinematical region. We report on our progress in analyzing different sources of systematic effects, such as the extrapolation of the kernel function chosen for the Chebsyhev approximation as well as the influence on the analysis in the region close to the kinematical limit
Updates on inclusive charmed and bottomed meson decays from the lattice
No full textWith the development of lattice QCD in recent years, a determination of decay rates for inclusive semileptonic decays from lattice correlators now seems viable. We report on the calculation of the inclusive semileptonic decay of the meson on the lattice. We simulate the process with M\"obius domain-wall charm and strange quarks, whose masses were approximately tuned to the physical values. We cover the whole kinematical region. We present a general overview on how the inclusive decays are treated on the lattice and discuss ongoing challenges, such as the estimation of systematic errors and future prospects of the project
Inclusive semi-leptonic <i>B</i><sub>(s)</sub> mesons decay at the physical<i> b</i> quark mass
No full textWe address the non-perturbative calculation of the decay rate of inclusive semi-leptonic mesons decays from lattice QCD. Precise theoretical Standard Model predictions are key ingredients in searches for new physics. This type of computation may eventually provide new insight into the long-standing tension between the inclusive and exclusive determinations of the CKM matrix elements and . We perform a pilot lattice computation for and improve on existing techniques. The valence-quark masses in our simulations are approximately physical for the domain-wall strange and charm quarks as well as for the bottom quark, for which we use a relativistic heavy quark effective action. We report on our progress and discuss future plans towards a first study with fully controlled systematic effects
Studies on finite-volume effects in the inclusive semileptonic decays of charmed mesons
No full textWe report on the calculation of the inclusive semileptonic decay of the Ds meson on the lattice. We simulate the Ds→Xsℓνℓ process with Möbius domain-wall charm and strange quarks, whose masses were approximately tuned to the physical values. We cover the whole kinematical region. The focus of this work is on the systematic error due to finite-volume effects. We construct a model of two-body final states to describe the data on a finite volume lattice of L≃0.055fm to investigate the extrapolation to the infinite-volume limit
Approaches to inclusive semileptonic -meson decays from Lattice QCD
Full text linkWe address the nonperturbative calculation of the inclusive decay rate of
semileptonic -meson decays from lattice QCD. Precise Standard-Model
predictions are key ingredients in searches for new physics, and this type of
computation may eventually provide new insight into the long-standing tension
between the inclusive and exclusive determinations of the
Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and . We
present results from a pilot lattice computation for , where the initial quark described by the relativistic-heavy-quark
(RHQ) formalism on the lattice and the other valence quarks discretised with
domain-wall fermions are simulated approximately at their physical quark
masses. We compare two different methods for computing the decay rate from
lattice data of Euclidean -point functions, namely Chebyshev and
Backus-Gilbert approaches. We further study how much the ground-state meson
dominates the inclusive decay rate and indicate our strategy towards a
computation with a more comprehensive systematic error budget.Comment: 43 pages, 18 figures. Add missing references, fix typo
Systematic effects in the lattice calculation of inclusive semileptonic decays
No full textWe report on the calculation of the inclusive semileptonic decay of the Ds meson on the lattice. We simulate the Ds→Xsℓνℓ process with Möbius domain-wall charm and strange quarks, whose masses are approximately tuned to their physical values. Our simulations cover the whole kinematical region. The focus of this work is to present updates on our strategies towards estimating the systematic uncertainties in the determination of the inclusive decay rate. We specifically focus on the systematic errors due to the choice of our approximation strategy and finite-volume effects
Inclusive semileptonic decays from lattice QCD: analysis of systematic effects
No full textLattice QCD calculations of inclusive semileptonic decay rates involve new types of systematic effects, such as truncation errors in the estimation of energy integrals, or finite-volume effects for multi-body final states. We investigate them for the lattice data of D_s \to X_s \ell\nu decays, obtained using Möbius domain-wall fermions. Separating the ground-state and excited-state contributions results in better control over these systematic effects. With the Chebyshev polynomial approximation, the truncation error is under control, while the finite-volume effects are estimated using a model to describe two-body final states
Study on the<i> P</i>-wave form factors contributing to <i>B<sub>s</sub></i> to<i> D<sub>s</sub></i> inclusive semileptonic decays from lattice simulations
No full textWe present a pilot study on extracting the form factors of the semileptonic decay of a Bs meson to the P-wave D∗∗s states from Bs four-point correlators. With their inclusive nature, four-point correlators include contributions from all possible final states. From the extracted P-wave form factors, we obtain numerical results for the corresponding Isgur-Wise form factors. The results suggest significant contributions from radial excitations to the Uraltsev sum rule at zero-recoil. In this pilot study, a coarse lattice of 243×64 with lattice spacing of 0.11fm is used for the analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
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