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Related papers: The Kaon B-parameter in quenched QCD

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The decay constants of the pseudoscalar mesons B and B_s are evaluated from QCD sum rules for the pseudoscalar two-point function. Recently calculated perturbative three-loop QCD corrections are incorporated into the sum rule. An analysis…

High Energy Physics - Phenomenology · Physics 2011-05-05 Matthias Jamin , Bjorn O. Lange

We present preliminary results on the computation of the QCD running coupling constant in the MOM_tilde scheme and Landau gauge with two flavours of dynamical Wilson quarks. Gluon momenta range up to about 7 GeV (beta=5.6, 5.8 and 6.0) with…

High Energy Physics - Phenomenology · Physics 2010-03-19 Ph. Boucaud , J. P. Leroy , J. Micheli , H. Moutarde , O. Pene , J. Rodriguez-Quintero , C. Roiesnel

We present estimates of light quarks masses using lattice data. Our main results are based on a global analysis of all the published data for Wilson and Staggered fermions, both in the quenched approximation and with $n_f=2$ dynamical…

High Energy Physics - Lattice · Physics 2016-09-01 R. Gupta , T. Bhattacharya

We determine Lambda_msbar for QCD with n_f=2 dynamical quark flavors by fitting the Q-Q-bar static potential known analytically in the perturbative regime up to terms of O(alpha_s^4) and ~alpha_s^4 ln(alpha_s) to corresponding results…

High Energy Physics - Phenomenology · Physics 2012-02-16 ETM Collaboration , Karl Jansen , Felix Karbstein , Attila Nagy , Marc Wagner

We present results for B_K and selected matrix elements for beyond the standard model interactions obtained in quenched QCD with overlap fermions. We also illustrate results on baryon wave-functions and diquark correlations within baryons…

High Energy Physics - Lattice · Physics 2008-11-26 Ronald Babich , Nicolas Garron , Christian Hoelbling , Joseph Howard , Laurent Lellouch , Claudio Rebbi

We present a perturbative calculation of the renormalization constants for the $\Delta B=2$ four-quark operators, which is needed to evaluate the bag parameters $B_B$ and $B_S$ in lattice QCD. The one-loop coefficients are calculated for…

High Energy Physics - Lattice · Physics 2009-10-31 S. Hashimoto , K-I. Ishikawa , T. Onogi , M. Sakamoto , N. Tsutsui , N. Yamada

We compute the running QCD coupling on the lattice by evaluating two-point and three-point off-shell gluon Green's functions in a fixed gauge and imposing non-perturbative renormalisation conditions on them. Our exploratory study is…

High Energy Physics - Lattice · Physics 2009-03-09 B. Alles , D. S. Henty , H. Panagopoulos , C. Parrinello , C. Pittori , D. G. Richards

We calculate the kaon B-parameter, B_K, in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We find that the resulting expression is similar to that in…

High Energy Physics - Lattice · Physics 2014-11-17 C. Aubin , Jack Laiho , Ruth S. Van de Water

Using non-perturbative techniques we have found the renormalisation factor, Z, in the RI-MOM scheme for quark bilinear operators in quenched QCD. We worked with overlap fermions using the Luescher-Weisz gauge action. Our calculation was…

High Energy Physics - Lattice · Physics 2016-09-01 M. Gürtler , R. Horsley , P. E. L. Rakow , C. J. Roberts , G. Schierholz , T. Streuer

We report on the ALPHA Collaboration's lattice B-physics programme based on N_f=2 O(a) improved Wilson fermions and HQET, including all NLO effects in the inverse heavy quark mass, as well as non-perturbative renormalization and matching,…

We use lattice QCD simulations, with MILC configurations (including vacuum polarization from u, d, and s quarks), to update our previous determinations of the QCD coupling constant. Our new analysis uses results from 6 different lattice…

High Energy Physics - Lattice · Physics 2009-01-08 C. T. H. Davies , K. Hornbostel , I. D. Kendall , G. P. Lepage , C. McNeile , J. Shigemitsu , H. Trottier

We perform the quenched lattice QCD analysis on the nuclear force (baryon-baryon interactions). We employ $20^3\times 24$ lattice at $\beta=5.7$ ($a\simeq 0.19$ fm) with the standard gauge action and the Wilson quark action with the hopping…

High Energy Physics - Lattice · Physics 2009-11-11 T. T. Takahashi , T. Doi , H. Suganuma

I calculate the QED coupling, alpha, directly in the MS-bar scheme using an unsubtracted dispersion relation for the three light quarks, and perturbative QCD for charm and bottom quarks. Compact analytical expressions are presented, making…

High Energy Physics - Phenomenology · Physics 2010-04-06 Jens Erler

We present a status report on our calculation of the renormalization constants for the quark bilinears in quenched (O(a)) improved Wilson theory at (beta=6.4) using quark states in Landau gauge.

High Energy Physics - Lattice · Physics 2010-05-27 Tanmoy Bhattacharya , Rajan Gupta , Weonjong Lee

We determine the value of the quark condensate from quenched QCD simulations on the lattice in two ways: (i) by using the GMOR formula; (ii) by comparing the OPE prediction for the Goldstone pole contribution to the pseudoscalar vertex, at…

High Energy Physics - Phenomenology · Physics 2009-11-10 Damir Becirevic , Vittorio Lubicz

We complete the non-perturbative calculations of the strange quark mass and the Lambda parameter in two flavor QCD by the ALPHA collaboration. The missing lattice scale is determined via the kaon decay constant, for whose chiral…

High Energy Physics - Lattice · Physics 2015-06-05 Patrick Fritzsch , Francesco Knechtli , Björn Leder , Marina Marinkovic , Stefan Schaefer , Rainer Sommer , Francesco Virotta

In this write-up we review and update our recent lattice QCD calculation of $B \to K^*$, $B_s \to \phi$, and $B_s \to K^*$ form factors [arXiv:1310.3722]. These unquenched calculations, performed in the low-recoil kinematic regime, provide…

High Energy Physics - Lattice · Physics 2015-04-07 R. R. Horgan , Z. Liu , S. Meinel , M. Wingate

Using domain wall fermions, we estimate $B_K(\mu\approx 2 GeV)=0.628(47)$ in quenched QCD which is consistent with previous calculations. At $\gbeta=6.0$ and 5.85 we find the ratio $f_K/m_\rho$ in agreement with the experimental value,…

High Energy Physics - Lattice · Physics 2009-10-30 T. Blum , A. Soni Brookhaven National Lab

This talk summarizes the status of the calculations of $B_K$, $B_7$, $B_8$, and $B_s$, done in collaboration with T. Bhattacharya, G. Kilcup, and S. Sharpe. Results for staggered, Wilson, and Clover fermions are presented.

High Energy Physics - Lattice · Physics 2009-10-30 Rajan Gupta

The status of Lattice QCD is reviewed with respect to results that are relevant to Standard Model phenomenology. I argue that in a few simple cases all (or almost all) systematic errors from the lattice calculation are under control.…

High Energy Physics - Phenomenology · Physics 2008-02-03 Aida X. El-Khadra