English
Related papers

Related papers: Recent progress in calculation of $B_K$ using stag…

200 papers

This work continues our program of lattice-QCD baryon physics using staggered fermions for both the sea and valence quarks. We present a proof-of-concept study that demonstrates, for the first time, how to calculate baryon matrix elements…

High Energy Physics - Lattice · Physics 2021-03-03 Yin Lin , Aaron S. Meyer , Steven Gottlieb , Ciaran Hughes , Andreas S. Kronfeld , James N. Simone , Alexei Strelchenko

We review recent progress in calculating kaon spectrum, pseudoscalar meson decay constants, $B_K$, $\epsilon'/\epsilon$, $K\to \pi\pi$ matrix elements, kaon semileptonic form factors, and moments of kaon distribution amplitudes on the…

High Energy Physics - Lattice · Physics 2008-11-26 Weonjong Lee

We present preliminary results from the 1991 HEMCGC simulations with staggered dynamical fermions on a $16^3 \times 32$ lattice at $\beta = 5.6$ with sea quark masses $am_q = 0.025$ and 0.01. The spectroscopy was done both for staggered…

In this revised version we have improved the treatment of the top and bottom quark mass. This leads to slight changes of the numerical results, especially of those presented in Fig.4. The discussion of the numerical procedure and accuracy…

High Energy Physics - Phenomenology · Physics 2009-10-22 Dmitri Diakonov , Maxim Polyakov , Peter Sieber , Joerg Schaldach , Klaus Goeke

We present updated results of a numerical improvement test with heavy-meson spectrum for the Oktay--Kronfeld (OK) action. The OK action is an extension of the Fermilab improvement program for massive Wilson fermions including all…

High Energy Physics - Lattice · Physics 2016-01-25 Jon A. Bailey , Yong-Chull Jang , Weonjong Lee , Carleton DeTar , Andreas S. Kronfeld , Mehmet B. Oktay

It is well established that lattice artifacts can be suppressed substantially by the use of SU(3)-projected smeared links in the fermion action. An example is the Highly Improved Staggered Quark action where the ASQ-like effective links are…

High Energy Physics - Lattice · Physics 2008-11-26 K. Y. Wong , R. M. Woloshyn

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

Smearing the gauge links of dynamical configurations removes small scale unphysical vacuum fluctuations and thus improves the chiral properties of lattice fermions. Recently we proposed the hypercubic smearing (HYP) that improves the flavor…

High Energy Physics - Lattice · Physics 2007-05-23 A. Hasenfratz , F. Knechtli

We present new results for light quark masses. The calculations are performed using two flavours of $O(a)$ improved Wilson fermions. We have reached lattice spacings as small as $a \sim 0.07$fm and pion masses down to $m_{\pi} \sim 340$MeV…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , G. Schierholz , T. Streuer , H. Stüben , J. M. Zanotti

We present the status of calculations of the form factors of the most relevant heavy-to-heavy and heavy-to-light decay channels. Using seven $N_f = 2+1+1$ HISQ ensembles, with lattice spacings ranging from 0.15 fm down to 0.06 fm, we…

We present recent progress in understanding weak matrix elements on the lattice. We use HYP staggered fermions in quenched QCD to study numerically various properties of the $K^+\to\pi^+$ amplitudes of the electroweak penguin operators…

High Energy Physics - Lattice · Physics 2007-05-23 Weonjong Lee , George T. Fleming

We give a progress report on studies of B_s and B_d mixing with valence NRQCD b quarks and asqtad light quarks on the MILC configurations including the effect of 2+1 flavours of sea quarks. We explore methods for reducing statistical and…

High Energy Physics - Lattice · Physics 2011-03-23 Elvira Gamiz , Christine T. H. Davies , G. Peter Lepage , Junko Shigemitsu , Matthew Wingate

We present a lattice QCD calculation of the heavy-light decay constants f_B and f_Bs performed with Nf=2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay constants have been also computed in the static…

We calculate one-loop matching factors for bilinear operators composed of improved staggered fermions. We compare the results for different improvement schemes used in the recent literature, including the HYP action and an action close to…

High Energy Physics - Lattice · Physics 2009-11-07 Weonjong Lee , Stephen R. Sharpe

I give a status report on the validity of the so-called ``fourth-root trick'', i.e. the procedure of representing the determinant for a single fermion by the fourth root of the staggered fermion determinant. This has been used by the MILC…

High Energy Physics - Lattice · Physics 2011-05-05 Stephen R. Sharpe

We present {\it preliminary} results for the spectrum and decay constants of B mesons using NRQCD heavy and Wilson light quarks on configurations at $\beta=5.6$ with two dynamical flavours of staggered fermions. All terms to order $1/M_Q$…

High Energy Physics - Lattice · Physics 2010-11-01 A. Ali Khan , S. Collins , C. T. H. Davies , U. M. Heller , J. Shigemitsu , J. H. Sloan

We present scaling studies for heavy-quark observables calculated with an $O(a^2)$-improved fermion action on tree-level Symanzik improved gauge configurations. Lattices of $1/a = $ 2.0-3.8 GeV with an equal physical volume 1.6 fm are used.…

High Energy Physics - Lattice · Physics 2014-12-22 Yong-Gwi Cho , Shoji Hashimoto , Jun-Ichi Noaki , Takashi Kaneko , Andreas Jüttner , Justus Tsang , Marina Marinkovic

We describe recent progress on generation of gauge configurations using the Highly Improved Staggered Quark (HISQ) action that was designed by the HPQCD/UKQCD collaboration. The HISQ action requires two levels of smearing with a…

We present the current status of the MILC collaboration's calculations of the properties of the light pseudoscalar meson sector. We use asqtad staggered ensembles with 2+1 dynamical flavors down to $a \approx 0.045$ fm and light quark mass…

We present results for the pion multiplet spectrum calculated using both unimproved staggered fermions and improved HYP-smeared staggered fermions. In the case of unimproved staggered fermions, we observe (consistent with previous work)…

High Energy Physics - Lattice · Physics 2008-11-26 Taegil Bae , Jongjeong Kim , Weonjong Lee , Stephen R. Sharpe