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Related papers: Update on $B_K$ and $\varepsilon_K$ with staggered…

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We use lattice QCD to calculate the form factors $f_+(q^2)$ and $f_0(q^2)$ for the semileptonic decay $B_s\to K\ell\nu$. Our calculation uses six MILC asqtad 2+1 flavor gauge-field ensembles with three lattice spacings. At the smallest and…

We report a new measurement of the CKM parameter V_ub made with a sample of 9.7 million B B-bar events collected with the CLEO II detector. Using Heavy Quark theory, we combine the observed yield of leptons from semileptonic B decay in the…

High Energy Physics - Experiment · Physics 2010-04-08 A. Bornheim , CLEO Collaboration

We present recent updates for $\varepsilon_K$ determined directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_K$, $|V_{cb}|$, $|V_{us}|$, $\xi_0$, $\xi_2$, $\xi_\text{LD}$, $f_K$, and $m_c$. We find that the…

High Energy Physics - Lattice · Physics 2022-03-04 Jeehun Kim , Yong-Chull Jang , Sunkyu Lee , Weonjong Lee , Jaehoon Leem , Chanju Park , Sungwoo Park

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}_{-…

High Energy Physics - Lattice · Physics 2008-11-26 Ian F. Allison , Christine T. H. Davies , Alan Gray , Andreas S. Kronfeld , Paul B. Mackenzie , James N. Simone

We give a progress report on a project aimed at a high-precision calculation of the decay constants $f_B$ and $f_{B_s}$ from simulations with HISQ heavy and light valence and sea quarks. Calculations are carried out with several heavy…

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 $964\pm16$ MeV with all sources…

High Energy Physics - Lattice · Physics 2021-02-10 Yin Lin , Aaron S. Meyer , Ciaran Hughes , Andreas S. Kronfeld , James N. Simone , Alexei Strelchenko

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…

High Energy Physics - Lattice · Physics 2011-11-09 E. Gamiz , C. DeTar , A. X. El-Khadra , A. S. Kronfeld , P. B. Mackenzie , J. Simone

The Fermilab Lattice and MILC collaborations are completing a comprehensive program of heavy-light physics on 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…

High Energy Physics - Lattice · Physics 2012-11-20 Si-Wei Qiu , Carleton DeTar , Daping Du , Andreas S. Kronfeld , Jack Laiho , Ruth Van de Water

We report improved measurements of the partial rate asymmetry (Acp) in B -> h h decays with 140fb^-1 of data collected with the Belle detector at the KEKB e+e- collider. Here h stands for a charged or neutral pion or kaon and in total five…

High Energy Physics - Experiment · Physics 2019-08-14 Y. Chao , P. Chang

We present an update on the analysis of semileptonic $B\rightarrow D^{(*)}$ decays at non-zero recoil. Our computation employs $2 + 1 + 1$ FNAL-MILC ensembles with highly improved staggered quark (HISQ) action for sea and light valence…

We present results of a numerical calculation of lattice QCD with two degenerate flavors of dynamical quarks, identified with up and down quarks, and with a strange quark treated in the quenched approximation. The lattice action and…

We report our light hadron mass calculation based on an increased statistics of 250 quenched gauge configurations on a (48^3 \times 64) lattice at (\beta = 6.5). Quark propagators are calculated for each of these configurations with…

High Energy Physics - Lattice · Physics 2009-10-30 Seyong Kim , Shigemi Ohta

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…

High Energy Physics - Lattice · Physics 2019-08-14 Steven Gottlieb , L. Levkova , M. Di Pierro , A. El-Khadra , A. S. Kronfeld , P. B. Mackenzie , J. Simone

Models of new physics induce K_0-K_0bar mixing through operators having Dirac structures other than the "left-left" form of the Standard Model. To carry out the chiral-continuum extrapolation of results from numerical simulations, one needs…

High Energy Physics - Lattice · Physics 2012-11-12 Jon A. Bailey , Hyung-Jin Kim , Weonjong Lee , Stephen R. Sharpe

We computed the B_K parameter on the lattice by using a non-perturbatively improved Wilson action. From our quenched simulation, in the MSbar scheme and at mu=2 GeV, we obtain B_K=0.73(7)^{+0.05}_{-0.01}. To gain some insight in the…

High Energy Physics - Lattice · Physics 2010-02-03 Damir Becirevic , Davide Meloni , Alessandra Retico

The following is an overview of the measurements of the CKM matrix elements V_cb and V_ub that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and recent advances in QCD calculations. In…

High Energy Physics - Experiment · Physics 2012-10-02 Vera G. Luth

These lectures review some of the progress made in the quantitative understanding of B decays. The emphasis here is on applications of QCD using perturbative and non-perturbative techniques. In some cases, however, phenomenological models…

High Energy Physics - Phenomenology · Physics 2011-04-15 A. Ali

Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters $\bar\rho$ and $\bar\eta$. In this brief review, I discuss the current status of lattice…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matthew Wingate

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…

High Energy Physics - Phenomenology · Physics 2008-11-26 Urs M. Heller

We give results for B, Bs, Bc and bottomonium spectroscopy using NRQCD heavy quarks and HISQ valence and sea quarks. Five MILC ensembles of gluon configurations with three values of the lattice spacing and m(light)/m(strange) values down to…

High Energy Physics - Lattice · Physics 2011-11-03 R. J. Dowdall