170 research outputs found
2+1 flavor simulations of QCD with improved staggered quarks
The MILC collaboration has been performing realistic simulations of full QCD
with 2+1 flavors of improved staggered quarks. Our simulations allow for
controlled continuum and chiral extrapolations. I present results for the light
pseudoscalar sector: masses and decay constants, quark masses and
Gasser-Leutwyler low-energy constants. In addition I will present some results
for heavy-light mesons, decay constants and semileptonic form factors, obtained
in collaboration with the HPQCD and Fermilab lattice collaborations. Such
calculations will help in the extraction of CKM matrix elements from
experimental measurements.Comment: To appear in the proceedings of QNP06, IVth International Conference
on Quarks and Nuclear Physics, Madrid, June 200
Hadronic matrix elements for B-mixing in the Standard Model and beyond
We use lattice QCD to calculate the B-mixing hadronic matrix elements for a
basis of effective four-quark operators that spans the space of all possible
contributions in, and beyond, the Standard Model. We present results for the
SU(3)-breaking ratio and discuss our ongoing calculation of the mixing matrix
elements, including the first calculation of the beyond the Standard Model
matrix elements from unquenched lattice QCD.Comment: 3 pages, 1 figure. Proceedings for CIPANP 2012 - Eleventh Conference
on the Intersections of Particle and Nuclear Physics, St. Petersburg FL, May
29 - June 3 201
FLIC-Overlap Fermions and Topology
APE smearing the links in the irrelevant operators of clover fermions
(Fat-Link Irrelevant Clover (FLIC) fermions) provides significant improvement
in the condition number of the Hermitian-Dirac operator and gives rise to a
factor of two savings in computing the overlap operator. This report
investigates the effects of using a highly-improved definition of the lattice
field-strength tensor F_mu_nu in the fermion action, made possible through the
use of APE-smeared fat links in the construction of the irrelevant operators.
Spurious double-zero crossings in the spectral flow of the Hermitian-Wilson
Dirac operator associated with lattice artifacts at the scale of the lattice
spacing are removed with FLIC fermions composed with an O(a^4)-improved lattice
field strength tensor. Hence, FLIC-Overlap fermions provide an additional
benefit to the overlap formalism: a correct realization of topology in the
fermion sector on the lattice.Comment: Lattice2002(chiral
Measurement of B(D+ -> mu+ nu) and the pseudoscalar decay constant f_D at CLEO
The analysis of 60 1/pb data collected on the psi(3770) resonance with the
CLEO-c detector has produced the first statistically significant signal for D+
-> mu+ nu decay and led to the measurement of the decay branching fraction B(D+
-> mu+ nu) = (3.5 +- 1.4 +- 0.6) x 10-4 and the pseudoscalar decay constant f_D
= (202 +- 41 +- 17) MeV.Comment: Talk presented at the 1st Meeting of the APS Topical Group on
Hadronic Physics (Fermilab, Oct. 24-26, 2004). LaTeX 4 pages, 2 figure
Mass of the B_c Meson in Three-Flavor Lattice QCD
We use lattice QCD to predict the mass of the meson. We use the MILC
Collaboration's ensembles of lattice gauge fields, which have a quark sea with
two flavors much lighter than a third. Our final result is
. The first error bar is a sum in quadrature
of statistical and systematic uncertainties, and the second is an estimate of
heavy-quark discretization effects.Comment: 4 pages, 3 figures; shorten to fit in PRL; published versio
Adoption and Implementation of Preventive Dentistry Initiatives for Physicians: A National Survey of Medicaid Programs
The objectives of this study are to: 1) identify Medicaid programs with initiatives in which non-dental primary care health clinicians provide preventive dental services for children; and 2) determine Medicaid dental directors' perceptions of the attributes of these preventive dental initiatives. A cross-sectional, web-based survey using QualtricsTM online survey software was administered to all state dental program managers. The survey included 50 items in 7 domains. Descriptive statistics were produced using QualtricsTM. An analysis of the primary hypothesis that tested the effect of initiative attributes on adoption was based on Roger's diffusion of innovation theory. Delivery of preventive dental services by physicians in Medicaid programs is becoming widespread in the United States. Adoption is affected more by perceived relative advantage of the innovation (e.g., the program is effective in improving access) than other attributes
Light-quark connected intermediate-window contributions to the muon g − 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, aHVP;LO
μ . We employ the MILC Collaboration’s isospin-symmetric QCD gauge-field
ensembles, which contain four flavors of dynamical highly improved staggered quarks with four lattice
spacings between a ≈ 0.06–0.15 fm and close-to-physical quark masses. We consider several effectivefield-
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 all;W
μ ðconnÞ ¼ 206.6ð1.0Þ × 10−10
and all;W2
μ ðconnÞ ¼ 100.7ð3.2Þ × 10−10, respectivelyUnited States Department of Energy (DOE)National Science Foundation (NSF) ACI-1548562
CNS-0521433
ACI-1532235
ACI-1532236
OCI-0725070
ACI-1238993
PHY17-19626
PHY20-13064
DGE 2040434Lilly Endowment, Inc.University of Colorado BoulderColorado State UniversityState of IllinoisBEISUK Research & Innovation (UKRI)
Science & Technology Facilities Council (STFC) ST/P002307/1
ST/R002452/1
ST/R00689X/1United States Department of Energy (DOE) DE-SC0010005
DE-SC0010120
DE-SC0011090
DE-SC0021006
DE-SC0015655Funding Opportunity Announcement Scientific Discovery through Advanced Computing: High Energy Physics LAB 22-2580Simons Foundation under their Simons Fellows in Theoretical Physics programUniversities Research Association Visiting Scholarship Awards 20-S-12
21-S-05SRA (Spain) PID2019-106087 GB-C21Junta de Andalucia FQM-101
A-FQM-467-UGR18
P18-FR-4314Spanish Government RYC2020-030244-IUK Research & Innovation (UKRI)
Science & Technology Facilities Council (STFC) ST/T000945/1Fermi Research Alliance, LLC (FRA) DE-AC02-07CH1135
B Mixing in the Standard Model and Beyond: Lattice QCD
We give a brief overview and progress report on our lattice QCD calculation
of neutral B mixing hadronic matrix elements needed for Standard Model and
Beyond the Standard Model physics. Reference [1] contains more details and
results.Comment: 3 pages, 0 figures, Proceedings of the 19th Particles and Nuclei
International Conference (PANIC11), Cambridge, MA, U.S.A., July 201
FLAG Review 2021
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereWe 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→ π transition at zero momentum transfer, as well as the decay constant ratio fK/ fπ and its consequences for the CKM matrix elements Vus and Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2) L× SU(2) R and SU(3) L× SU(3) R Chiral Perturbation Theory. We review the determination of the BK 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 mc and mb 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 αs. 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 quantitie
Semileptonic form factors for B -> D*lv at nonzero recoil from 2+1-flavor lattice QCD
We present the first unquenched lattice-QCD calculation of the form factors for the decay B -> D*t nu at nonzero recoil. Our analysis includes 15 MILC ensembles with N-f = 2 + 1 flavors of asqtad sea quarks, with a strange quark mass close to its physical mass. The lattice spacings range from a asymptotic to 0.15 fm down to 0.045 fm, while the ratio between the light-and the strange-quark masses ranges from 0.05 to 0.4. The valence b and c quarks are treated using the Wilson-clover action with the Fermilab interpretation, whereas the light sector employs asqtad staggered fermions. We extrapolate our results to the physical point in the continuum limit using rooted staggered heavy-light meson chiral perturbation theory. Then we apply a model independent parametrization to extend the form factors to the full kinematic range. With this parametrization we perform a joint lattice-QCD/experiment fit using several experimental datasets to determine the CKM matrix element |V-cb|. We obtain |V-cb| = (38.40 +/- 0.68(th) +/- 0.34(exp) +/- 0.18(EM)) x 10(-3). The first error is theoretical, the second comes from experiment and the last one includes electromagnetic and electroweak uncertainties, with an overall chi(2)/dof = 126/84, which illustrates the tensions between the experimental data sets, and between theory and experiment. This result is in agreement with previous exclusive determinations, but the tension with the inclusive determination remains. Finally, we integrate the differential decay rate obtained solely from lattice data to predict R(D*) = 0.265 +/- 0.013, which confirms the current tension between theory and experiment.United States Department of Energy (DOE)National Science Foundation's Teragrid/XSEDE ProgramUnited States Department of Energy (DOE) DE-FG02-13ER41976
DE-SC0009998
DE-SC0010120
DE-SC0015655National Science Foundation (NSF) PHY17-19626
PHY14-17805
SRA (Spain) P18-FR-4314Consejeria de Economia, Innovacion, Ciencia y Empleo, Junta de Andalucia (Spain) P18-FR-4314
A-FQM-467-UGR18Fermilab Distinguished Scholars Progra
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