|
|
Albertus, C., Aoki, Y., Boyle, P. A., Christ, N. H., Dumitrescu, T. T., Flynn, J. M., et al. (2010). Neutral B-meson mixing from unquenched lattice QCD with domain-wall light quarks and static b quarks. Phys. Rev. D, 82(1), 014505–29pp.
Abstract: We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the "2 + 1'' flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice spacing of a approximate to 0.11 fm (a(-1) = 1.729 GeV) and a lattice spatial volume of approximately (1.8 fm)(3). We simulate at three different light sea quark masses with pion masses down to approximately 430 MeV, and extrapolate to the physical quark masses using a phenomenologically-motivated fit function based on next-to-leading order heavy-light meson SU(2) chiral perturbation theory. For the b-quarks, we use an improved formulation of the Eichten-Hill action with static link-smearing to increase the signal-to-noise ratio. We also improve the heavy-light axial current used to compute the B-meson decay constant to O(alpha(s)pa) using one-loop lattice perturbation theory. We present initial results for the SU(3)-breaking ratios f(Bs)/f(Bd) and xi = f(Bs)root B-Bs/f(Bd)root B-Bd, thereby demonstrating the viability of the method. For the ratio of decay constants, we find f(Bs)/f(Bd) = 1.15(12) and for the ratio of mixing matrix elements, we find xi = 1.13(12), where in both cases the errors reflect the combined statistical and systematic uncertainties, including an estimate of the size of neglected O(1/m(b)) effects.
|
|
|
|
Flavour Lattice Averaging Group(Aoki, Y. et al), Hernandez, P., & Ramos, A. (2022). FLAG Review 2021. Eur. Phys. J. C, 82(10), 869–296pp.
Abstract: We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor f(+) (0) arising in the semileptonic K -> pi transition at zero momentum transfer, as well as the decay constant ratio Alf, and its consequences for the CKM matrix elements V-us and V-ud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)(L) x SU(2)(R) and SU(3)(L) x SU(3)(R) Chiral Perturbation Theory. We review the determination of the B-K parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for m(c) and m(b) as well as those for the decay constants, form factors, and mixing parameters of charmed and bottom mesons and baryons. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant alpha(s). We consider nucleon matrix elements, and review the determinations of the axial, scalar and tensor bilinears, both isovector and flavor diagonal. Finally, in this review we have added a new section reviewing determinations of scale-setting quantities.
|
|
