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The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms., Comment: 229 pages

Quantum chromodynamics (QCD) reduces the strong interactions, in all their variety, to a simple nonabelian gauge theory. It clearly and elegantly explains hadrons at short distances, which has led to its universal acceptance. Since its advent, however, many of its long-distance, emergent properties have been believed to be true, without having been demonstrated to be true. This paper reviews a variety of results in this regime that have been established with lattice gauge theory, directly from the QCD Lagrangian. This body of work sheds light on the origin of hadron masses, its interplay with dynamical symmetry breaking, as well as on other intriguing features such as the phase structure of QCD. In addition, nonperturbative QCD is quantitatively important to many aspects of particle physics (especially the quark flavor sector), nuclear physics, and astrophysics. This review also surveys some of the most interesting connections to those subjects., Comment: invited review for Annual Reviews of Nuclear and Particle Science (2012); 21 pp., 4 tables, 6 figures. v2: Figures 2 and 5 updated; references added; many minor wording changes and clarifications; conforms closely to accepted version

We calculate form-factor ratios between the semileptonic decays \bar{B}->D^+\ell^-\bar{\nu} and \bar{B}_s->D_s^+\ell^-\bar{\nu} with lattice QCD. These ratios are a key theoretical input in a new strategy to determine the fragmentation fractions of the neutral B decays, which are needed for measurements of BR(B^0_s-> \mu^+\mu^-). We use the MILC ensembles of gauge configurations with 2+1 flavors of sea quarks at two lattice spacings of approximately 0.12 fm and 0.09 fm. We use the model-independent z-parametrization to extrapolate our simulation results at small recoil toward maximum recoil. Our results for the form-factor ratios are $f_0^{(s)}(M^2_\pi)/f_0^{(d)}(M^2_K) =1.046(44)_{stat.}(15)_{syst.}$ and $f_0^{(s)}(M^2_\pi)/f_0^{(d)}(M^2_\pi)=1.054(47)_{stat.}(17)_{syst.}$. In contrast to a QCD sum-rule calculation, no significant departure from U-spin (d<->s) symmetry is observed., Comment: 30 pages, 11 figures. Fig. 1 updated. Table II added. Conforms with version published in Physical Review D, except typos fixed, as in the PRD Erratum, in Table V (previously Table IV in arXiv v1). Results unchanged

We report on the status of our lattice-QCD calculation of the hadronic contribution to $B_d^0$ and $B^0_s$ mixing, with 2+1 flavors of dynamical sea quarks. Preliminary results for hadronic mixing matrix elements are given for a basis of five four-quark, dimension-six, $\Delta B=2$ mixing operators that spans the space of all possible hadronic mixing contributions in the Standard Model and beyond. At the intermediate stage of analysis reported on in this work, our errors are competitive with published Standard Model matrix element results. For beyond the Standard Model matrix elements, this is the first unquenched calculation and the first new lattice-QCD calculation in ten years., Comment: 13 pages, 6 figures. Proceedings of the XXIX International Symposium on Lattice Field Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California. Ver 2: New Figs. 2-4 and Table 4 corrects scripting error. Table 4 now includes results for BJU as well as BBGLN choice of evanescent operators

We give an update on simulation results for the decay constants f_B, f_{B_s}, f_D and f_{D_s}. These decay constants are important for precision tests of the standard model, in particular entering as inputs to the global CKM unitarity triangle fit. The results presented here make use of the MILC (2+1)-flavor asqtad ensembles, with heavy quarks incorporated using the clover action with the Fermilab method. Partially quenched, staggered chiral perturbation theory is used to extract the decay constants at the physical point. In addition, we give error projections for a new analysis in progress, based on an extended data set., Comment: 7 pages, 2 figures. Proceedings of the XXIX International Symposium on Lattice Field Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California

We calculate the leptonic decay constants of B_{(s)} and D_{(s)} mesons in lattice QCD using staggered light quarks and Fermilab bottom and charm quarks. We compute the heavy-light meson correlation functions on the MILC asqtad-improved staggered gauge configurations which include the effects of three light dynamical sea quarks. We simulate with several values of the light valence- and sea-quark masses (down to ~m_s/10) and at three lattice spacings (a ~ 0.15, 0.12, and 0.09 fm) and extrapolate to the physical up and down quark masses and the continuum using expressions derived in heavy-light meson staggered chiral perturbation theory. We renormalize the heavy-light axial current using a mostly nonperturbative method such that only a small correction to unity must be computed in lattice perturbation theory and higher-order terms are expected to be small. We obtain f_{B^+} = 196.9(8.9) MeV, f_{B_s} = 242.0(9.5) MeV, f_{D^+} = 218.9(11.3) MeV, f_{D_s} = 260.1(10.8) MeV, and the SU(3) flavor-breaking ratios f_{B_s}/f_{B} = 1.229(26) and f_{D_s}/f_{D} = 1.188(25), where the numbers in parentheses are the total statistical and systematic uncertainties added in quadrature., Comment: 63 pages, 13 figures

The measured partial widths of the semileptonic decays D to K l nu and D to pi l nu can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V_cs| and |V_cd|. The lattice calculations can be checked by comparing the form factor shapes from the lattice and experiment. We have generated a sizable data set by using heavy clover quarks with the Fermilab interpretation for charm and asqtad staggered light quarks on 2+1 flavor MILC ensembles with lattice spacings of approximately 0.12, 0.09, 0.06, and 0.045 fm. Preliminary fits to staggered chiral perturbation theory suggest that we can reduce the uncertainties in the form factors at zero invariant mass to below 5%., Comment: 7 pages, 4 figures, proceedings of the XXIX International Symposium on Lattice Field Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California

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 2011

We report on the status of the Fermilab-MILC calculation of the form factor f_+^{K pi}(0), needed to extract the CKM matrix element |V_{us}| from experimental data on K semileptonic decays. The HISQ formulation is used in the simulations for the valence quarks, while the sea quarks are simulated with the asqtad action (MILC N_f=2+1 configurations). We discuss the general methodology of the calculation, including the use of twisted boundary conditions to get values of the momentum transfer close to zero and the different techniques applied for the correlators fits. We present initial results for lattice spacings a=0.12fm and a=0.09fm, and several choices of the light quark masses., Comment: 7 pages, 4 figures, presented at The XXIX International Symposium on Lattice Field Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California

We study the $B \to Kl^+l^-$ semileptonic decay process in three-flavor lattice QCD. We analyze several ensembles generated by the MILC collaboration at different lattice spacings and sea-quark masses. We use the asqtad improved staggered action for the light quarks and the clover action with the Fermilab interpretation for the heavy $b$ quark. We present preliminary results for the vector current induced form factors for a range of kaon energies. Our analysis includes chiral and continuum extrapolations based on SU(2) staggered \chi PT., Comment: 7 pages, 4 figures, presented at The XXIX International Symposium on Lattice Field Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California

The Fermilab Lattice-MILC collaboration is completing a comprehensive program of heavy-light physics on the MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20. We use the Fermilab interpretation of the clover action for heavy valence quarks and the asqtad action for light valence quarks. The central goal of the program is to provide ever more exacting tests of the unitarity of the CKM matrix. We give a progress report on one part of the program, namely the analysis of the semileptonic decay B to D at both zero and nonzero recoil. Although final results are not presented, we discuss improvements in the analysis methods, the statistical errors, and the parameter coverage that we expect will lead to a significant reduction in the final error for |V_cb| from this decay channel., Comment: 7 pages, 3 figures, LATTICE 2011 conference

We examine the taste structure of eigenvectors of the staggered-fermion Dirac operator. We derive a set of conditions on the eigenvectors of modes with small eigenvalues (near-zero modes), such that staggered fermions reproduce the 't Hooft vertex in the continuum limit. We also show that, assuming these conditions, the correlators of flavor-singlet mesons are free of contributions singular in $1/m$, where $m$ is the quark mass. This conclusion holds also when a single flavor of sea quark is represented by the fourth root of the staggered-fermion determinant. We then test numerically, using the HISQ action, whether these conditions hold on realistic lattice gauge fields. We find that the needed structure does indeed emerge., Comment: 24 pages, 21 figures, v2 clarifies a dependence and matches published version

Recently, the Fermilab heavy-quark action was extended to include dimension-six and -seven operators in order to reduce the discretization errors. In this talk, we present results of the first numerical simulations with this action (the OK action), where we study the masses of the quarkonium and heavy-light systems. We calculate combinations of masses designed to test improvement and compare results obtained with the OK action to their counterparts obtained with the clover action. Our preliminary results show a clear improvement., Comment: 7 pages, 3 figures, Talk presented at 28th International Symposium On Lattice Field Theory (Lattice 2010) 13-19 Jun 2010, Villasimius, Sardinia, Italy

We give a progress report on the calculation of B meson mixing matrix elements, focusing on contributions that could arise beyond the Standard Model. The calculation uses asqtad (light quark) and Fermilab (heavy quark) valence actions and MILC ensembles with 2+1 flavors of asqtad sea quarks. We report preliminary B^0_s fit results, at a lattice spacing of 0.12 fm, for the SUSY basis of effective four-quark mixing operators and include an estimate for the final error budget., Comment: 2 references added to introduction. 7 pages, 4 figures, Presented at the XXVIII International Symposium on Lattice Field Theory June 14-19, 2010, Villasimius, Sardinia Italy

The experimentally measured rates of the semileptonic decays K -> pi l nu and D -> K(pi) l nu can be combined with lattice calculations of the associated form factors to precisely extract the CKM matrix elements |V_{us}| and |V_{cs(d)}|. We report on the status of form factor calculations with Fermilab charm quarks and staggered light quarks on the 2+1 flavor asqtad staggered MILC ensembles. Analysis of data for the D -> pi l nu form factor provides a nontrivial test of our methods via comparison with CLEO data. We discuss the use of HISQ valence quarks to calculate the K -> pi l nu form factor f_+^{K pi}(0) and describe tests of our method., Comment: 8 pp., 5 figs, presented at Lattice 2010, June 14-19, 2010, Villasimius, Italy

We present an update of our calculation of the form factor for B -> D* l nu at zero recoil, with higher statistics and finer lattices. As before, we use the Fermilab action for b and c quarks, the asqtad staggered action for light valence quarks, and the MILC ensembles for gluons and light quarks (L\"uscher-Weisz married to 2+1 rooted staggered sea quarks). In this update, we have reduced the total uncertainty on F(1) from 2.6% to 1.7%. At Lattice2010 we presented a still-blinded result, but this writeup includes the unblinded result from the September 2010 CKM workshop., Comment: 7 pp., 2 figs, presented at Lattice 2010, June 14-19, 2010, Villasimius, Italy

When the Lake Louise Winter Institute started twenty-five years ago, many properties of quantum chromodynamics (QCD) were believed to be true, but had not been demonstrated to be true. This talk surveys a variety of results that have been established with lattice gauge theory, directly from the QCD Lagrangian, shedding light on the origin of (your) mass and its interplay with dynamical symmetry breaking, as well as some further intriguing features of the natural world., Comment: 12pp. Prepared for the Lake Louise Winter Institute, February 15-20, 2010, Lake Louise, Alberta, Canada

We report the non-perturbative tuning of parameters--- kappa_c, kappa_b, and kappa_crit ---that determine the heavy-quark mass in the Fermilab action. This requires the computation of the masses of Ds^(*) and Bs^(*) mesons comprised of a Fermilab heavy quark and a staggered light quark. Additionally, we report the hyperfine splittings for Ds and Bs mesons as a cross-check of our simulation and analysis methods. We find a splitting of 145 +/- 15 MeV for the Ds system and 40 +/- 9 MeV for the Bs system. These are in good agreement with the Particle Data Group average values of 143.9 +/- 0.4 MeV and 46.1 +/- 1.5 MeV, respectively. The calculations are carried out with the MILC 2+1 flavor gauge configurations at three lattice spacings $a$ approximately 0.15, 0.12, and 0.09 fm., Comment: 34 pages, 8 figures, 26 tables; some sections rearranged for clarity; conclusions unchanged; version accepted by Phys. Rev.D

This Resource Letter provides a guide to the literature on Quantum Chromodynamics (QCD), the relativistic quantum field theory of the strong interactions. Journal articles, books, and other documents are cited for the following topics: quarks and color, the parton model, Yang-Mills theory, experimental evidence for color, QCD as a color gauge theory, asymptotic freedom, QCD for heavy hadrons, QCD on the lattice, the QCD vacuum, pictures of quark confinement, early and modern applications of perturbative QCD, the determination of the strong coupling and quark masses, QCD and the hadron spectrum, hadron decays, the quark-gluon plasma, the strong nuclear interaction, and QCD's role in nuclear physics. The letter {E} after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter {I}, for intermediate level, indicates material of a somewhat more specialized nature, and the letter {A} indicates rather specialized or advanced material., Comment: 39 pp., 11 figures; resource material for courses on QCD, prepared for American Journal of Physics; v3 conforms with published version; v4 corrects repetition of Fig. 7's image as Fig. 10

We present the leptonic decay constants fDs and fD+ computed on the MILC collaboration's 2+1 flavor asqtad gauge ensembles. We use clover heavy quarks with the Fermilab interpretation and improved staggered light quarks. The simultaneous chiral and continuum extrapolation, which determines both decay constants, includes partially-quenched lattice results at lattice spacings a ~ 0:09, 0:12 and 0:15 fm. We have made several recent improvements in our analysis: a) we include terms in the fit describing leading order heavy-quark discretization effects, b) we have adopted a more precise input r1 value consistent with our other D and B meson studies, c) we have retuned the input bare charm masses based upon the new r1. Our preliminary results are fDs = 260 +/-10 MeV and fD+ = 217 +/-10 MeV., Comment: contribution to LATTICE 2009

We report on calculations of the charmonium and bottomonium spectrum in lattice QCD. We use ensembles of gauge fields with three flavors of sea quarks, simulated with the asqtad improved action for staggered fermions. For the heavy quarks we employ the Fermilab interpretation of the clover action for Wilson fermions. These calculations provide a test of lattice QCD, including the theory of discretization errors for heavy quarks. We provide, therefore, a careful discussion of the results in light of the heavy-quark effective Lagrangian. By and large, we find that the computed results are in agreement with experiment, once parametric and discretization errors are taken into account., Comment: 21 pages, 17 figures

Recent measurements of the branching fraction for D_s -> l nu disagree with the Standard Model by around 2sigma. In this case the key aspect of the Standard Model is the calculation of the decay constant, f_{D_s}, with lattice QCD. This talk surveys the experimental measurements, and explains how the lattice QCD calculations are done. Should the discrepancy strengthen again (it was earlier 3.8sigma), it would be a signal of new physics. Models that could explain such an effect are also discussed., Comment: 7 pp.; 1 fig.; prepared for the XXIX Physics in Collision, Kobe, Japan, August 30 - September 2, 2009

Lattice calculations of the form factors for the charm semileptonic decays D to K l nu and D to pi l nu provide inputs to direct determinations of the CKM matrix elements |V(cs)| and |V(cd)| and can be designed to validate calculations of the form factors for the bottom semileptonic decays B to pi l nu and B to K l l-bar. We are using Fermilab charm (bottom) quarks and asqtad staggered light quarks on the 2+1 flavor asqtad MILC ensembles to calculate the charm (bottom) form factors. We outline improvements to the previous calculation of the charm form factors and detail our progress. We expect our current round of data production to allow us to reduce the theoretical uncertainties in |V(cs)| and |V(cd)| from 10.5% and 11%, respectively, to about 7%., Comment: 7 pages, 2 figures, parallel talk at 27th International Symposium on Lattice Field Theory (Lattice 2009), Beijing, China, 25-31 Jul 2009; typos corrected

We present results from an ongoing lattice study of the lowest lying charmonium and bottomonium level splittings using the Fermilab heavy quark formalism. Our objective is to test the performance of this action on MILC-collaboration ensembles of (2+1) flavors of light improved staggered (asqtad) quarks. Measurements are done on 16 ensembles with degenerate up and down quarks of various masses, thus permitting a chiral extrapolation, and over lattice spacings ranging from 0.09 fm to 0.18 fm, thus permitting study of lattice-spacing dependence. We examine combinations of the mass splittings that are sensitive to components of the effective quarkonium potential., Comment: Lattice 2009. 8 pp

We update results presented at Lattice 2005 on charmonium masses. New ensembles of gauge configurations with 2+1 flavors of improved staggered quarks have been analyzed. Statistics have been increased for other ensembles. New results are also available for P-wave mesons and for bottomonium on selected ensembles., Comment: 7 pages, 10 figures, Lattice 2006 (Spectroscopy), Tucson, Arizona, appeared in the on-line proceedings long ago. A better paper should appear soon

One of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor and measurements and theoretical interpretations of their results have advanced tremendously: apart from masses and quantum numbers of flavor particles, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. Till early 1990s observations of CP violation were confined to neutral $K$ mesons, but since then a large number of CP-violating processes have been studied in detail in neutral $B$ mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of $K, D$, and $B$ mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field., Comment: Report of the CKM workshop, Rome 9-13th Sep. 2008, 340 pages, 106 postscript figures, submitted to Phys. Repts

Comparisons of lattice-QCD calculations of semileptonic form factors with experimental measurements often display two sets of points, one each for lattice QCD and experiment. Here we propose to display the output of a lattice-QCD analysis as a curve and error band. This is justified, because lattice-QCD results rely in part on fitting, both for the chiral extrapolation and to extend lattice-QCD data over the full physically allowed kinematic domain. To display an error band, correlations in the fit parameters must be taken into account. For the statistical error, the correlation comes from the fit. To illustrate how to address correlations in the systematic errors, we use the Becirevic-Kaidalov parametrization of the D -> pi l nu and D -> K l nu form factors, and a analyticity-based fit for the B -> pi l nu form factor f_+., Comment: 6 pp; v2 conforms with published version (one additional sentence and reference to clarify a point)

We present an update of our calculations of the decay constants of the D, D_s, B, and B_s mesons in unquenched 2+1 flavor QCD. We use the MILC library of improved staggered gauge ensembles at lattice spacings 0.09, 0.12, and 0.15 fm, clover heavy quarks with the Fermilab normalizations, and improved staggered light valence quarks., Comment: 7 pages; based on talked presented by P. Mackenzie at the XXVI International Symposium on Lattice Field Theory, July 14-19 2008, Williamsburg, Virginia, USA

Recent measurements of the branching fraction for D_s -> l nu disagree with the Standard Model expectation, which relies on calculations of $f_{D_s}$ from lattice QCD. This paper uses recent preliminary measurements from CLEO and a new preliminary lattice-QCD result from this conference to update the significance of the discrepancy. The "f_{D_s} puzzle" stands now at 3.5sigma, with sigma predominantly from the statistical uncertainty of the experiments. New physics scenarios that could solve the puzzle would also lead to non-Standard amplitudes mediating the semileptonic decays D -> K l nu. This paper shows where the new amplitudes enter the differential rate and outlines where lattice QCD calculations are needed to confront recent and forthcoming measurements., Comment: 9 pp. Parallel talk at Lattice 2008. arXiv version includes appendix with more details on BSM semileptonic amplitude and rate

We calculate the form factor f_+(q^2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge configurations generated by the MILC Collaboration. We simulate with several light quark masses and at two lattice spacings, and extrapolate to the physical quark mass and continuum limit using heavy-light meson staggered chiral perturbation theory. We then fit the lattice result for f_+(q^2) simultaneously with that measured by the BABAR experiment using a parameterization of the form factor shape in q^2 which relies only on analyticity and unitarity in order to determine the CKM matrix element |V(ub)|. This approach reduces the total uncertainty in |V(ub)| by combining the lattice and experimental information in an optimal, model-independent manner. We find a value of |V(ub)| x 10^3 = 3.38 +/- 0.36., Comment: 59 pages, 11 figures v2: Added table with form factor covariance matrix. Added references. v3: Fixed typos. Corrected heavy-quark discretization errors and subsequent determination of Vub. Central value of Vub unchanged, but error in Vub changed in last decimal place. Version submitted to Phys. Rev. D

We present the first lattice QCD calculation of the form factor for B-> D* l nu with three flavors of sea quarks. We use an improved staggered action for the light valence and sea quarks (the MILC configurations), and the Fermilab action for the heavy quarks. The form factor is computed at zero recoil using a new double ratio method that yields the form factor more directly than the previous Fermilab method. Other improvements over the previous calculation include the use of much lighter light quark masses, and the use of lattice (staggered) chiral perturbation theory in order to control the light quark discretization errors and chiral extrapolation. We obtain for the form factor, F_{B-> D*}(1)=0.921(13)(20), where the first error is statistical and the second is the sum of all systematic errors in quadrature. Applying a 0.7% electromagnetic correction and taking the latest PDG average for F_{B-> D*}(1)|V_cb| leads to |V_cb|=(38.7 +/- 0.9_exp +/- 1.0_theo) x 10^-3., Comment: 48 pages, 9 figures. Sections VI and VII D clarified, minor typos corrected and references added. Version published in PRD

We survey results in lattice quantum chromodynamics from groups in the USQCD Collaboration. The main focus is on physics, but many aspects of the discussion are aimed at an audience of computational physicists., Comment: 17 pp. Featured presentation at Scientific Discovery with Advanced Computing, July 13-17, Seattle

The measured rate for D_s -> l nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8 sigma level. We discuss how robust the theoretical prediction is, and we show that the discrepancy with experiment may be explained by a charged Higgs boson or a leptoquark., Comment: 4 pages; v2 conforms with PRL version

We extend the Fermilab method for heavy quarks to include interactions of dimensions 6 and 7 in the action. There are, in general, many new interactions, but we carry out the calculations needed to match the lattice action to continuum QCD at the tree level, finding six non-zero couplings. Using the heavy-quark theory of cutoff effects, we estimate how large the remaining discretization errors are. We find that our tree-level matching, augmented with one-loop matching of the dimension-five interactions, can bring these errors below 1%, at currently available lattice spacings., Comment: 43 pp; v2 conforms with PRD version, improving plots and many minor things

Many results from lattice QCD of broad importance to particle and nuclear physics are obtained with 2+1 flavors of staggered sea quarks. In the continuum limit, staggered fermions yield four species, called tastes. To reduce the number of tastes to one (per flavor), the simulation employs the fourth root of the four-taste staggered fermion determinant. This talk surveys evidence in favor of this procedure, refutes recent criticisms, and reviews recent algorithmic and technical improvements. Physics results are covered in other plenary talks., Comment: 25 pages; Lattice 2007 (plenary); v2 corrects typos, adds references, moves endnote to footnote, and conforms with version published in PoS

We report on heavy quark mass calculations using Fermilab heavy quarks. Lattice calculations of heavy-strange meson masses are combined with one-loop (automated) lattice perturbation theory to arrive at the quark mass. Mesons are constructed from Fermilab heavy quarks and staggered light quarks. We use the MILC ensembles at three lattice spacings and sea quark mass ratios of $m_{\rm u,d} / m_{\rm s} = 0.1$ to 0.4. Preliminary results for the bottom quark are given in the potential subtracted scheme., Comment: 7pp. contribution to Lattice 2007, Regensburg, Germany, 30th July - 4th August, 2007

We present results of a perturbative matching calculation performed at one-loop for heavy-light currents. We use the Fermilab action for the heavy quarks, the Asqtad action for the light quarks, and an improved gluon action. We also present results for heavy-heavy currents with Fermilab heavy quarks and improved glue., Comment: proceedings for the XXV International Symposium on Lattice Field Theory, July 30-4 August 2007, Regensburg, Germany, 7 pages, 4 figures

The heavy-quark expansion for inclusive semi-leptonic B decays introduces $\bar{\Lambda}$ and $\lambda_1$, which are matrix elements in heavy-quark effective field theory. We review how they can be obtained from an analysis of the heavy quark mass dependence of heavy-light meson masses in lattice QCD. We present preliminary results for the bottom quark mass, $m_b$, using $\bar{\Lambda}$ and $\lambda_1$ for the $B_s$ meson from a 2+1 sea-flavor unquenched calculation., Comment: 7 pp., contribution to Lattice 2006 (Electroweak Decays and Mixing)

We extend the Fermilab method for heavy quarks to include all interactions of dimension six in the action. We discuss a subtlety in the power counting, which implies that, for heavy quarks, certain interactions of dimension seven are commensurate with some of those of dimension six. We then present tree-level matching conditions obtained from calculating the Compton scattering amplitude for (lattice) QCD. When the matching conditions have been applied, the improved action removes (tree-level) discretization errors of order $a^2\bm{p}^3/m_Q$ and $a^3\bm{p}^3$., Comment: 1+5 pp., contribution to Lattice 2006(Quark Masses, Gauge Couplings, and Renormalization)

In recent years, we used lattice QCD to calculate some quantities that were unknown or poorly known. They are the $q^2$ dependence of the form factor in semileptonic $D\to Kl\nu$ decay, the leptonic decay constants of the $D^+$ and $D_s$ mesons, and the mass of the $B_c$ meson. In this paper, we summarize these calculations, with emphasis on their (subsequent) confirmation by measurements in $e^+e^-$, $\gamma p$ and $\bar{p}p$ collisions., Comment: 5 pages; update of hep-lat/0509169, with experimental confirmation of form factors from Belle and fDs from BaBar; presented at SciDAC 2006 for the Fermilab Lattice, MILC, and HPQCD Collaborations

We have greatly extended an earlier calculation of the charmonium spectrum on three flavor dynamical quark ensembles by using more recent ensembles generated by the MILC collaboration. The heavy quarks are treated using the Fermilab formulation. The charmonium state masses are in reasonable agreement with the observed spectrum; however, some of the spin splittings may still be too small., Comment: 6 pages, 6 figures, presented at Lattice2005(Heavy quark physics), Dublin, July 25-30, 2005, to appear in Proceedings of Science

In the past year, we calculated with lattice QCD three quantities that were unknown or poorly known. They are the $q^2$ dependence of the form factor in semileptonic $D\to Kl\nu$ decay, the decay constant of the $D$ meson, and the mass of the $B_c$ meson. In this talk, we summarize these calculations, with emphasis on their (subsequent) confirmation by experiments., Comment: v1: talk given at the International Conference on QCD and Hadronic Physics, Beijing, June 16-20, 2005; v2: poster presented at the XXIIIrd International Symposium on Lattice Field Theory, Dublin, July 25-30

We present the first lattice QCD calculation with realistic sea quark content of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain f_{D^+} = 201 +/- 3 +/- 17 MeV, where the errors are statistical and a combination of systematic errors. We also obtain f_{D_s} = 249 +/- 3 +/- 16 MeV for the D_s meson., Comment: note added on recent CLEO measurement; PRL version

We use lattice QCD to predict the mass of the $B_c$ 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 $m_{B_c}=6304\pm12^{+18}_{- 0} MeV$. 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 version

We determine the leptonic decay constants in three flavor unquenched lattice QCD. We use O(a^2)-improved staggered light quarks and O(a)-improved charm quarks in the Fermilab heavy quark formalism. Our preliminary results, based upon an analysis at a single lattice spacing, are f_Ds = 263(+5-9)(+/-24) MeV and f_D = 225(+11-13)(+/-21) MeV. In each case, the first reported error is statistical while the is the combined systematic uncertainty., Comment: Talk presented at Lattice2004(heavy), Fermilab, June 21-26, 2004. 3 pages, 2 figures

We present results for form factors of semileptonic decays of $D$ and $B$ mesons in 2+1 flavor lattice QCD using the MILC gauge configurations. With an improved staggered action for light quarks, we successfully reduce the systematic error from the chiral extrapolation. The results for $D$ decays are in agreement with experimental ones. The results for B decays are preliminary. Combining our results with experimental branching ratios, we then obtain the CKM matrix elements $|V_{cd}|$, $|V_{cs}|$, $|V_{cb}|$ and $|V_{ub}|$. We also check CKM unitarity, for the first time, using only lattice QCD as the theoretical input., Comment: Talk presented at Lattice2004(heavy); 3 pages, 3 figures

We perform a precise calculation of the mass of the B_c meson using unquenched configurations from the MILC collaboration including 2+1 flavours of improved staggered quarks. Lattice NRQCD and the Fermilab formalism are used to describe the b and c quarks respectively. We find the mass of the B_c meson to be 6.304(16) GeV, Comment: Talk presented at Lattice2004(heavy), Fermilab, June 21-26. 3 pages, 2 figures

We present the first three-flavor lattice QCD calculations for $D\to \pi l\nu$ and $D\to K l\nu$ semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC collaboration. With an improved staggered action for light quarks, we are able to simulate at light quark masses down to 1/8 of the strange mass. Consequently, the systematic error from the chiral extrapolation is much smaller than in previous calculations with Wilson-type light quarks. Our results for the form factors at $q^2=0$ are $f_+^{D\to\pi}(0)=0.64(3)(6)$ and $f_+^{D\to K}(0) = 0.73(3)(7)$, where the first error is statistical and the second is systematic, added in quadrature. Combining our results with experimental branching ratios, we obtain the CKM matrix elements $|V_{cd}|=0.239(10)(24)(20)$ and $|V_{cs}|=0.969(39)(94)(24)$, where the last errors are from experimental uncertainties., Comment: Fermilab Lattice, MILC, and HPQCD Collaborations; 4 pp

This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics., Comment: Lattice2003(plenary), 14 pages, 5 figures

We present preliminary results for the D_s meson spectrum and decay constants in unquenched lattice QCD. Simulations are carried out with 2+1 dynamical quarks using gauge configurations generated by the MILC collaboration. We use the ``asqtad'' a^2 improved staggered action for the light quarks, and the clover heavy quark action with the Fermilab interpretation. We compare our spectrum results with the newly discovered 0+ and 1+ states in the D_s system., Comment: 3pp. Presented at 21st International Symposium on Lattice Field Theory (LATTICE 2003), Tsukuba, Ibaraki, Japan, 15-19 Jul 2003