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Simone, James N.

Publications and source records attributed to Simone, James N..

4 records
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DOE OSTI2024

B-meson semileptonic decays from highly improved staggered quarks

We present an update for results on B-meson semileptonic decays using the highly improved staggered quark (HISQ) action for both valence and 2+1+1 sea quarks. The use of the highly improvedaction, combined with the MILC collaborationโ€™s gauge ensembles with lattice spacings down to $\sim$0.03fm, allows the $b$ quark to be treated with the same discretization as the lighter quarks. The talk willfocus on updated results for $B_{(s)} \to D_{(s)}$, $B_{(s)} \to K$ scalar and vector form factors.

Lytle, Andrewโ†—
DOE OSTI2023

Light-quark connected intermediate-window contributions to the muon ๐‘” โˆ’ 2 hadronic vacuum polarization from lattice QCD

We present a lattice-QCD calculation of the light-quark connected contribution to window observables associated with the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, $a^{HVP,LO}_ฮผ$. We employ the MILC Collaborationโ€™s isospin-symmetric QCD gauge-field ensembles, which contain four flavors of dynamical highly improved staggered quarks with four lattice spacings between $a โ‰ˆ 0.06-0.15$ fm and close-to-physical quark masses. We consider several effective-field-theory-based schemes for finite volume and other lattice corrections and combine the results via Bayesian model averaging to obtain robust estimates of the associated systematic uncertainties. After unblinding, our final results for the intermediate and "W2" windows are $a^{U,W}_ฮผ$(conn) = 206.6(1.0) x 10 -10 and $a^{U,W2}_ฮผ$ (conn) = 100.7(3.2) x 10 -10 , respectively

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSโ†—
DOE OSTI2021

Nucleon mass with highly improved staggered quarks

We present the first computation in a program of lattice-QCD baryon physics using staggered fermions for sea and valence quarks. For this initial study, we present a calculation of the nucleon mass, obtaining 964 ยฑ16 MeV with all sources of statistical and systematic errors controlled and accounted for. This result is the most precise determination to date of the nucleon mass from first principles. We use the highly improved staggered quark action, which is computationally efficient. Three gluon ensembles are employed, which have approximate lattice spacings ๐‘Ž โ‰ˆ 0.09, 0.12, and 0.15 fm, each with equal-mass ๐‘ข/๐‘‘, ๐‘ , and ๐‘ quarks in the sea. Further, all ensembles have the light valence and sea ๐‘ข/๐‘‘ quarks tuned to reproduce the physical pion mass, avoiding complications from chiral extrapolations. Our work opens a new avenue for precise calculations of baryon properties, which are both feasible and relevant to experiments in particle and nuclear physics.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSโ†—