showing 7 related works from this author
Improving the kinetic couplings in lattice nonrelativistic QCD
2019
We improve the non-relativistic QCD (NRQCD) action by comparing the dispersion relation to that of the continuum through $\mathcal{O}(p^6)$ in perturbation theory. The one-loop matching coefficients of the $\mathcal{O}(p^4)$ kinetic operators are determined, as well as the scale at which to evaluate $\alpha_s$ in the $V$-scheme for each quantity. We utilise automated lattice perturbation theory using twisted boundary conditions as an infrared regulator. The one-loop radiative corrections to the mass renormalisation, zero-point energy and overall energy-shift of an NRQCD $b$-quark are also found. We also explore how a Fat$3$-smeared NRQCD action and changes of the stability parameter $n$ aff…
Determination of m¯b/m¯c and m¯b from nf=4 lattice QCD+QED
2021
We extend HPQCD's earlier ${n}_{f}=2+1+1$ lattice-QCD analysis of the ratio of $\overline{\mathrm{MS}}$ masses of the $b$ and $c$ quark to include results from finer lattices (down to 0.03 fm) and a new calculation of QED contributions to the mass ratio. We find that ${\overline{m}}_{b}(\ensuremath{\mu})/{\overline{m}}_{c}(\ensuremath{\mu})=4.586(12)$ at renormalization scale $\ensuremath{\mu}=3\text{ }\text{ }\mathrm{GeV}$. This result is nonperturbative. Combining it with HPQCD's recent lattice $\mathrm{QCD}+\mathrm{QED}$ determination of ${\overline{m}}_{c}(3\text{ }\text{ }\mathrm{GeV})$ gives a new value for the $b$-quark mass: ${\overline{m}}_{b}(3\text{ }\text{ }\mathrm{GeV})=4.513(2…
Flavor physics in the quark sector
2010
218 páginas, 106 figuras, 89 tablas.-- arXiv:0907.5386v2.-- Report of the CKM workshop, Rome 9-13th Sep. 2008.-- et al.
Improved Vcs determination using precise lattice QCD form factors for D→Kℓν
2021
We provide a 0.8%-accurate determination of Vcs from combining experimental results for the differential rate of D→K semileptonic decays with precise form factors that we determine from lattice QCD. This is the first time that Vcs has been determined with an accuracy that allows its difference from 1 to be seen. Our lattice QCD calculation uses the highly improved staggered quark (HISQ) action for all valence quarks on gluon field configurations generated by the MILC Collaboration that include the effect of u, d, s, and c HISQ quarks in the sea. We use eight gluon field ensembles with five values of the lattice spacing ranging from 0.15 fm to 0.045 fm and include results with physical u/d q…
Hindered M1 radiative decay ofϒ(2S)from lattice NRQCD
2015
We present a calculation of the hindered M1 $\mathrm{\ensuremath{\Upsilon}}(2S)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{b}(1S)\ensuremath{\gamma}$ decay rate using lattice nonrelativistic quantum chromodynamics. The calculation includes spin-dependent relativistic corrections to the NRQCD action through $\mathcal{O}({v}^{6})$ in the quark's relative velocity, relativistic corrections to the leading order current which mediates the transition through the quark's magnetic moment, radiative corrections to the leading spin-magnetic coupling and for the first time a full error budget. We also use gluon field ensembles at multiple lattice spacing values, all of which include $u$, $d$, $s$ and…
Bottomonium precision tests from full lattice QCD: Hyperfine splitting, ϒ leptonic width, and b quark contribution to e+e−→hadrons
2021
We calculate the mass difference between the $\mathrm{\ensuremath{\Upsilon}}$ and ${\ensuremath{\eta}}_{b}$ and the $\mathrm{\ensuremath{\Upsilon}}$ leptonic width from lattice QCD using the highly improved staggered quark formalism for the $b$ quark and including $u$, $d$, $s$ and $c$ quarks in the sea. We have results for lattices with lattice spacing as low as 0.03 fm and multiple heavy quark masses, enabling us to map out the heavy quark mass dependence and determine values at the $b$ quark mass. Our results are ${M}_{\mathrm{\ensuremath{\Upsilon}}}\ensuremath{-}{M}_{{\ensuremath{\eta}}_{b}}=57.5(2.3)(1.0)\text{ }\text{ }\mathrm{MeV}$ (where the second uncertainty comes from neglect of …
The anomalous magnetic moment of the muon in the Standard Model
2020
We are very grateful to the Fermilab Directorate and the Fermilab Theoretical Physics Department for their financial and logistical support of the first workshop of the Muon g -2 Theory Initiative (held near Fermilab in June 2017) [123], which was crucial for its success, and indeed for the successful start of the Initiative. Financial support for this workshop was also provided by the Fermilab Distinguished Scholars program, the Universities Research Association through a URA Visiting Scholar award, the Riken Brookhaven Research Center, and the Japan Society for the Promotion of Science under Grant No. KAKEHNHI-17H02906. We thank Shoji Hashimoto, Toru Iijima, Takashi Kaneko, and Shohei Nis…