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Related papers: FLAVOR-SINGLET g_A FROM LATTICE QCD

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Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large…

High Energy Physics - Lattice · Physics 2011-06-21 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , J. Noaki , T. Onogi

We report on simulations of QCD with many flavors of degenerate quarks, the DBW2 gauge action and naive staggered fermions, using the rational hybrid Monte Carlo algorithm. We primarily focus on eight degenerate quark flavors where a…

High Energy Physics - Lattice · Physics 2009-02-05 Xiao-Yong Jin , Robert D. Mawhinney

We describe the first lattice determination of the strong coupling constant with 3 flavors of dynamical quarks. The method follows previous analyses in using a perturbative expansion for the plaquette and Upsilon spectroscopy to set the…

High Energy Physics - Lattice · Physics 2015-06-25 C. Davies , A. Gray , M. Alford , E. Follana , J. Hein , P. Lepage , Q. Mason , M. Nobes , J. Shigemit su , H. Trottier , M. Wingate

Previous lattice QCD calculations of axial vector and pseudoscalar form factors show significant deviation from the partially conserved axial current (PCAC) relation between them. Since the original correlation functions satisfy PCAC, the…

High Energy Physics - Lattice · Physics 2020-02-26 Yong-Chull Jang , Rajan Gupta , Boram Yoon , Tanmoy Bhattacharya

Using the Schr\"odinger functional (SF) with a single staggered fermion field we calculate the SF coupling in four-flavour QCD for a wide range of energies and lattice sizes up to $L/a=16$. Preliminary results for the continuum…

High Energy Physics - Lattice · Physics 2010-12-01 Paula Pérez-Rubio , Stefan Sint

We present the first unquenched lattice-QCD calculation of the form factors for the decay $B\rightarrow D^\ast\ell\nu$ at nonzero recoil. Our analysis includes 15 MILC ensembles with $N_f=2+1$ flavors of asqtad sea quarks, with a strange…

We report our present status of on-going project on the measurement of the static quark potential in 2+1 flavour domain wall QCD with various improved gauge actions and couplings. Lattice spacing determined from Sommer scale on these…

High Energy Physics - Lattice · Physics 2019-08-14 Koichi Hashimoto , Taku Izubuchi , Jun Noaki

We present preliminary results for the determination of the leading strange and charm quark-connected contributions to the hadronic vacuum polarization contribution to the muon's g-2. Measurements are performed on the RC* collaboration's…

This work presents the first lattice-QCD calculation of the twist-3 axial quark GPDs for the proton using the large-momentum effective theory approach. We calculate matrix elements with momentum-boosted proton states and a non-local axial…

Axion models with generation-dependent Peccei-Quinn charges can lead to flavor-changing neutral currents, thus motivating QCD axion searches at precision flavor experiments. We rigorously derive limits on the most general effective…

High Energy Physics - Phenomenology · Physics 2020-08-05 Jorge Martin Camalich , Maxim Pospelov , Pham Ngoc Hoa Vuong , Robert Ziegler , Jure Zupan

We present results for the hyperon vector form factor f_1 for $\Xi^0 \rightarrow \Sigma^+ l\bar{\nu}$ and $\Sigma^- \rightarrow n l\bar{\nu}$ semileptonic decays from dynamical lattice QCD with domain-wall quarks. Simulations are performed…

High Energy Physics - Lattice · Physics 2015-05-27 Shoichi Sasaki

It is widely believed that chiral symmetry is spontaneously broken at zero temperature in the strong coupling limit of staggered fermions, for any number of colors and flavors. Using Monte Carlo simulations, we show that this conventional…

High Energy Physics - Lattice · Physics 2015-06-11 Philippe de Forcrand , Seyong Kim , Wolfgang Unger

The semileptonic process, B --> \pi l \nu, is studied via full QCD Lattice simulations. We use unquenched gauge configurations generated by the MILC collaboration. These include the effect of vacuum polarization from three quark flavors:…

High Energy Physics - Lattice · Physics 2014-11-17 Emel Gulez , Alan Gray , Matthew Wingate , Christine T. H. Davies , G. Peter Lepage , Junko Shigemitsu

We report on a numerical reinvestigation of the Aoki phase in lattice QCD with two flavors of Wilson fermions where the parity-flavor symmetry is spontaneously broken. For this purpose an explicitly symmetry-breaking source term…

High Energy Physics - Lattice · Physics 2007-05-23 E. -M. Ilgenfritz , W. Kerler , M. Mueller-Preussker , A. Sternbeck , H. Stueben

We investigate the coupling constant $g_{\sigma\pi\pi}$ for the hadronic decay $\sigma\to\pi\pi$ only using the relevant three-point function, which is evaluated by the moving-wall source technique with a pretty good noise-to-signal ratio.…

High Energy Physics - Lattice · Physics 2017-02-28 Lingyun Wang , Ziwen Fu , Hang Chen

I extend to QCD an efficient method for lattice gauge theory with dynamical fermions. Once the eigenvalues of the Dirac operator and the density of states of pure gluonic configurations at a set of plaquette energies (proportional to the…

High Energy Physics - Lattice · Physics 2009-11-07 Xiang-Qian Luo

We investigate the phase structure of lattice QCD for general number of flavors $N_F$. Based on numerical data combined with the results of the perturbation theory we propose the following picture: When $N_F \ge 17$, there is only one IR…

High Energy Physics - Lattice · Physics 2008-11-26 Y. Iwasaki , K. Kanaya , S. Kaya , S. Sakai , T. Yoshié

The isoscalar axial-vector form factor of the nucleon plays a key role in understanding the electroweak interaction of nucleons. For the interpretation of the spin structure of the nucleon the non-singlet isoscalar axial charge is…

We present a two-flavor QCD calculation of $B_K$ on a $16^3 \times 32$ lattice at $a\sim 0.12$ fm (or equivalently $a^{-1}\sim$1.67 GeV). Both valence and sea quarks are described by the overlap fermion formulation. The matching factor is…

High Energy Physics - Lattice · Physics 2019-08-13 S. Aoki , H. Fukaya , S. Hashimoto , J. Noaki , T. Kaneko , H. Matsufuru , T. Onogi , N. Yamada

We present the results of the first direct determination of the g_{D^* D pi} coupling using lattice QCD. From our simulations in the quenched approximation, we obtain g_{D^* D pi} = 18.8 +/- 2.3^{+1.1}_{-2.0} and hat(g) = 0.67 +/-…

High Energy Physics - Lattice · Physics 2010-03-19 A. Abada , D. Becirevic , Ph. Boucaud , G. Herdoiza , J. P. Leroy , A. Le Yaouanc , O. Pene , J. Rodriguez-Quintero