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

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We have measured some simple matrix elements for pseudoscalar and vector mesons made of Wilson valence quarks and staggered sea quarks at $\beta=5.6$ at sea quark masses $am_q=0.01$ and 0.025. Our measurements include the decay constants of…

The improved staggered quark action has enabled breakthrough calculations of QCD with three light dynamical quarks. The largest remaining $a^2$ scaling violations come from "taste-changing" interactions, which are significantly reduced over…

High Energy Physics - Lattice · Physics 2009-11-10 Eduardo Follana , Quentin Mason , Christine Davies , Kent Hornbostel , Peter Lepage , Howard Trottier

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…

We introduce a new class of actions for staggered quarks in lattice QCD which significantly reduce flavour symmetry violations in the pion mass spectrum. An action introduced by the MILC collaboration for the same purpose is seen to be a…

High Energy Physics - Lattice · Physics 2016-08-25 J. -F. Lagae , D. K. Sinclair

We report on the status of our kaon semileptonic form factor calculations using the highly-improved staggered quark (HISQ) formulation to simulate the valence fermions. We present results for the form factor f_+^{K \pi}(0) on the asqtad…

In the last decade, the LEP and SLD experiments played a central role in the study of B hadrons (hadrons containing a b quark). New B hadrons have been observed ($B^0_s$, \Lambda_b$, $\Xi_b$ and $B^{**}$) and their production and decay…

High Energy Physics - Phenomenology · Physics 2010-11-23 A. Stocchi

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…

We extend the picture of $B$-meson decay constants obtained in lattice QCD beyond those of the $B$, $B_s$ and $B_c$ to give the first full lattice QCD results for the $B^*$, $B^*_s$ and $B^*_c$. We use improved NonRelativistic QCD for the…

High Energy Physics - Lattice · Physics 2015-07-01 B. Colquhoun , C. T. H. Davies , R. J. Dowdall , J. Kettle , J. Koponen , G. P. Lepage , A. T. Lytle

We present results for matching factors for staggered four-fermion operators constructed using HYP-smeared fat links both in the action and the operators. We use perturbation theory to calculate the matching factors and work to one-loop…

High Energy Physics - Lattice · Physics 2011-03-10 Jongjeong Kim , Weonjong Lee , Stephen R. Sharpe

Preliminary results from simulations with 2+1 dynamical quark flavors at a lattice spacing of 0.09 fm are combined with earlier results at a=0.13 fm. We examine the approach to the continuum limit and investigate the dependence of the…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard , T. Burch , T. DeGrand , C. DeTar , Steven Gottlieb , E. B. Gregory , U. M. Heller , J. Osborn , R. Sugar , D. Toussaint

The MILC Collaboration has been producing ensembles of lattice configurations with three dynamical flavors for the past few years. There are now results for three lattice spacings for a variety of light and strange quark masses, ranging…

High Energy Physics - Lattice · Physics 2009-11-10 Steven Gottlieb

We present preliminary results at {\beta} = 1.95 (a = 0.077 fm) on the first unquenched N_f=2+1+1 lattice computation of the B_K parameter which controls the neutral kaon oscillations in the Standard Model. Using N_f=2+1+1 maximally twisted…

High Energy Physics - Lattice · Physics 2011-11-08 N. Carrasco , V. Gimenez , P. Dimopoulos , R. Frezzotti , D. Palao , G. C. Rossi , V. Lubicz , M. Papinutto , F. Sanfilippo , S. Simula

Belle II has recently reported the new measurement ${\cal B}(B^+\to K^+\nu\bar\nu)=(2.3\pm0.7)\times 10^{-5}$ \cite{Belle-II:2023esi} which is two times larger than their previous result (although consistent within errors) and about…

High Energy Physics - Phenomenology · Physics 2024-03-25 Xiao-Gang He , Xiao-Dong Ma , German Valencia

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 present the first lattice QCD calculation of the decay constants f_B and f_{B_s} with physical light quark masses. We use configurations generated by the MILC collaboration including the effect of u, d, s and c HISQ sea quarks at three…

High Energy Physics - Lattice · Physics 2013-06-05 R. J. Dowdall , C. T. H. Davies , R. R. Horgan , C. J. Monahan , J. Shigemitsu

We report improved measurements of $B$ to pseudoscalar-vector decays containing an $\omega$ meson in the final states. Our results are obtained from a data sample that contains $388\times 10^{6}$ $B\bar{B}$ pairs accumulated at the…

High Energy Physics - Experiment · Physics 2019-08-14 by C. -M. Jen , P. Chang , K. Abe , K. Abe , I. Adachi , H. Aihara

We present comprehensive results for the spectrum and decay constants of hadrons containing a single b quark. The heavy quark is simulated using an $O(1/M)$ NRQCD action and the light quark using the $O(a)$ tadpole-improved clover action on…

High Energy Physics - Lattice · Physics 2010-01-18 S. Collins , C. T. H. Davies , U. M. Heller , A. Ali Khan , J. Shigemitsu , J. Sloan , C. Morningstar

We report calculations of B_K using two flavours of dynamical clover-improved Wilson lattice fermions and look for dependence on the dynamical quark mass at fixed lattice spacing. We see some evidence for dynamical quark effects. In…

High Energy Physics - Lattice · Physics 2019-08-14 J. M. Flynn , F. Mescia , A. S. B. Tariq

Semileptonic, B --> pi l,nu, decays are studied on the MILC dynamical configurations using NRQCD heavy and Asqtad light quarks. We work with light valence quark masses ranging between m_s and m_s/8. Preliminary simple linear chiral…

High Energy Physics - Lattice · Physics 2009-11-10 J. Shigemitsu , C. T. H. Davies , A. Dougall , K. Foley , E. Gamiz , A. Gray , E. Gulez , G. P. Lepage , M. Wingate

We present a study of the $D$ and $B$ leptonic decay constants on the MILC $N_f=2+1$ asqtad gauge ensembles using asqtad-improved staggered light quarks and clover heavy quarks in the Fermilab interpretation. Our previous analysis…

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