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Related papers: $|V_{ub}|$ determination in lattice QCD

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We investigate high density state of SU(2) QCD by using Lattice QCD simulation with Wilson fermions. The ratio of fermion determinants is evaluated at each step of the Metropol is link update by Woodbury formula. At $\beta=0.7$, and $\kappa…

Nuclear Theory · Physics 2007-05-23 S. Muroya , A. Nakamura , C. Nonaka

We study QCD with two flavors of dynamical Wilson fermions at $\beta = 5.5$ and three values of $\kappa$. The corresponding pion masses are 0.375, 0.324 and 0.262 in lattice units, with pion to rho mass ratios of 0.76, 0.71 and 0.62,…

High Energy Physics - Lattice · Physics 2009-10-28 K. M. Bitar , R. G. Edwards , U. M. Heller , A. D. Kennedy

Recent results from lattice QCD simulations provide a realistic picture, based upon first principles, of~$\Upsilon$ physics. We combine these results with the experimentally measured mass of the $\Upsilon$~meson to obtain an accurate and…

High Energy Physics - Lattice · Physics 2009-10-22 C. T. H. Davies , K. Hornbostel , A. Langnau , G. P. Lepage , A. Lidsey , C. J. Morningstar , J. Shigemitsu , J. Sloan

I convey an idea of the significant recent progress, which opens up good perspectives for high-precision ab-initio computations in heavy flavour physics based on lattice QCD. This report focuses on the strategy and the challenges of fully…

High Energy Physics - Lattice · Physics 2011-04-05 Jochen Heitger

Heavy meson HQET light-cone distribution amplitudes (LCDAs) are critical for precision predictions of $B$ meson weak decays, but currently are one of dominant theoretical uncertainties that obscure interpretations of $B$ anomalies and…

We calculate the vacuum polarization functions on the lattice using the overlap fermion formulation.By matching the lattice data at large momentum scales with the perturbative expansion supplemented by Operator Product Expansion (OPE), we…

High Energy Physics - Lattice · Physics 2019-08-13 E. Shintani , S. Aoki , T. W. Chiu , S. Hashimoto , T. H. Hsieh , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada

We perform a detailed, fully-correlated study of the chiral behavior of the pion mass and decay constant, based on 2+1 flavor lattice QCD simulations. These calculations are implemented using tree-level, O(a)-improved Wilson fermions, at…

Using a fully relativistic lattice fermion action, we compute the form factors of the semileptonic decay $B\to\pi\ell\nu$, which is required for the determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{ub}|$. We employ the…

High Energy Physics - Lattice · Physics 2023-01-03 Brian Colquhoun , Shoji Hashimoto , Takashi Kaneko , Jonna Koponen

After a pedagogical introduction to the calculation of weak matrix elements on the lattice, I review some of the lattice's most recent predictions concerning the weak decays of $B$-mesons. Amongst the topics covered are the determinations…

High Energy Physics - Phenomenology · Physics 2009-03-20 Laurent Lellouch

I present preliminary results of next-generation lattice-QCD calculations of the $\Lambda_b \to p$, $\Lambda_b \to \Lambda$, and $\Lambda_b \to \Lambda_c$ form factors based on RBC/UKQCD gauge-field ensembles with 2+1 flavors of domain-wall…

High Energy Physics - Lattice · Physics 2023-10-03 Stefan Meinel

We present an investigation of the electromagnetic pion form factor, $F_\pi(Q^2)$, at small values of the four-momentum transfer $Q^2$ ($\lesssim 0.25$ GeV$^2$), based on the gauge configurations generated by European Twisted Mass…

The most common predictions for rare $K$ and $B$ decay branching ratios in the Standard Model are based on the CKM elements $|V_{cb}|$ and $|V_{ub}|$ resulting from global fits, that are in the ballpark of their inclusive and exclusive…

High Energy Physics - Phenomenology · Physics 2022-08-10 Andrzej J. Buras , Elena Venturini

We study the hadronic spectrum in quenched lattice QCD using an improved Wilson fermion action (Hamber-Wu(1983),Eguchi-Kawamoto(1984)) at $\beta= 5.7$ and $\beta =6.0$. We find a systematic reduction of the finite spacing effects compared…

High Energy Physics - Lattice · Physics 2009-10-22 M. -P. Lombardo , G. Parisi , A. Vladikas

We present a lattice QCD calculation of the pion scalar form factor and associated radii with fully controlled systematics. Lattice results are computed on a large set of 17 gauge ensembles with $N_f=2+1$ Wilson Clover-improved sea quarks.…

High Energy Physics - Lattice · Physics 2025-03-27 Konstantin Ottnad , Georg von Hippel

Lattice QCD calculations using gauge smearing for fermion kernels are computationally efficient. Hypercubic blocking (nHYP smearing) has been shown to reduce scaling errors. In this work we use an improved action for $N_f=2$ QCD, based on…

High Energy Physics - Lattice · Physics 2020-11-18 Hossein Niyazi , Andrei Alexandru , Frank X. Lee , Ruairí Brett

We have developed two methods for handling $b$ quarks in lattice QCD. One uses NRQCD (now improved to include radiative corrections) and the other uses Highly Improved Staggered Quarks (HISQ), extrapolating to the $b$ quark from lighter…

High Energy Physics - Lattice · Physics 2013-12-23 C. T. H. Davies , B. Colquhoun , B. Galloway , G. C. Donald , J. Koponen , R. J. Dowdall , R. Horgan , E. Follana , G. P. Lepage , C. McNeile

A precision method for determining |Vub| using the full range in q^2 of B-> pi \ell nu data is presented. At large q^2 the form factor is taken from unquenched lattice QCD, at q^2=0 we impose a model independent constraint obtained from B->…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Christian Arnesen , Ben Grinstein , Ira Z. Rothstein , Iain W. Stewart

We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $\eta$ and $\eta^\prime$ mesons in $N_f=2+1$ QCD\@. The results are obtained using twenty-one CLS ensembles of non-perturbatively…

High Energy Physics - Lattice · Physics 2021-08-27 Gunnar S. Bali , Vladimir Braun , Sara Collins , Andreas Schäfer , Jakob Simeth

We extract the Cabibbo-Kobayashi-Maskawa matrix element $V_{cb}$ from the exclusive decays of $\Lambda_b\to \Lambda_c\ell\bar \nu_\ell$ and $\Lambda_b\to \Lambda_c M_{(c)}$ with $M=(\pi^-,K^-)$ and $M_c=(D^-,D^-_s)$, where the branching…

High Energy Physics - Phenomenology · Physics 2017-11-02 Y. K. Hsiao , C. Q. Geng

I review the current status of the determination of Vus from a lattice perspective. The recent progress are very impressive: computation with 2 + 1 and 2 + 1 + 1 dynamical flavours, physical pion mass, several fine lattices, different…

High Energy Physics - Phenomenology · Physics 2014-11-27 Nicolas Garron