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We present a lattice QCD determination of the vector form factor of the kaon semileptonic decay K -> pi l nu which is relevant for the extraction of the CKM matrix element |V_{us}| from experimental data. Our result is based on the gauge…

High Energy Physics - Lattice · Physics 2014-11-06 Nuria Carrasco , Paolo Lami , Vittorio Lubicz , Eleonora Picca , Lorenzo Riggio , Silvano Simula , Cecilia Tarantino

We point out that the lower bound on $m_t$ from the CP violation parameter $\epsilon_K$ has increased considerably. Using Wolfenstein parametrization of the CKM matrix we derive an analytic expression for this bound as a function of $\mid…

High Energy Physics - Phenomenology · Physics 2010-11-01 Andrzej J. Buras

We analyze the CP violating ratio \epe=epsilon'/epsilon in the Standard Model in view of the new KTeV results. We review the present status of the most important non-perturbative parameters B_6, B_8, B_K and of the strange quark mass m_s.…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Bosch , A. J. Buras , M. Gorbahn , S. Jäger , M. Jamin , M. E. Lautenbacher , L. Silvestrini

The Kaon direct CP violation $Re(\epsilon'_K/\epsilon_K)$ below the experimental data of a $2\sigma$ in the standard model, which is calculated using the RBC-UKQCD lattice and a large $N_c$ dual QCD, indicates the necessity of a new physics…

High Energy Physics - Phenomenology · Physics 2018-09-26 Chuan-Hung Chen , Takaaki Nomura

We study direct CP violation in the hadronic decay $B^{\pm} \to \rho^{0}\pi^{\pm}$, including the effect of $\rho - \omega$ mixing. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements, especially the…

High Energy Physics - Phenomenology · Physics 2010-02-17 X. -H. Guo , O. Leitner , A. W. Thomas

The $K\to\pi\pi$ system is analyzed in the chiral limit within the Standard Model. We discuss how to connect the short-distance running in the $|\Delta S|=1$ case to the matrix-elements calculated in a low-energy approximation in a…

High Energy Physics - Phenomenology · Physics 2009-10-31 Johan Bijnens , Joaquim Prades

The 2012 PDG reports a tension at the level of $3 \sigma$ between two exclusive determinations of $|V_{ub}|$. They are obtained by combining the experimental branching ratios of $B \to \tau \nu$ and $B \to \pi l \nu$ (respectively) with a…

High Energy Physics - Lattice · Physics 2012-11-28 F. Bahr , F. Bernardoni , B. Blossier , J. Bulava , M. Della Morte , P. Fritzsch , N. Garron , A. Gérardin , J. Heitger , G. von Hippel , A. Ramos , H. Simma , R. Sommer

The low energy dynamics of QCD is investigated with special attention paid to the matching between QCD and chiral perturbation theory(ChPT), and also to some useful algebraic chiral operator relations which survive even when we include…

High Energy Physics - Phenomenology · Physics 2014-11-17 Yue-Liang Wu

We propose a method to determine the CKM matrix element $|V_{ub}|$ using the global $q^2$ dependence of the dispersive bound on the form factors for $B\to \pi l\nu$ decay. Since the lattice calculation of the $B\to \pi l\nu$ form factor is…

High Energy Physics - Lattice · Physics 2009-11-10 Masaru Fukunaga , Tetsuya Onogi

The more precise extraction for the CKM matrix element |V_{cb}| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. Y. Wang , Y. L. Wu , Y. A. Yan , M. Zhong , Y. B. Zuo

We present a new analysis of the ratio epsilon'/epsilon within the Standard Model (SM) using a formalism that is manifestly independent of the values of leading (V-A)x(V-A) QCD penguin, and EW penguin hadronic matrix elements of the…

High Energy Physics - Phenomenology · Physics 2016-01-27 Andrzej J. Buras , Martin Gorbahn , Sebastian Jäger , Matthias Jamin

The two most precise determinations of the CKM matrix element V_us are based on the analyses of leptonic and semileptonic kaon decays. These studies also rely on the lattice QCD calculations of two hadronic parameters, namely the ratio of…

High Energy Physics - Lattice · Physics 2013-09-11 Vittorio Lubicz

We study the exclusive semileptonic $B$-meson decays $B\to K(\pi)\ell^+\ell^-$, $B\to K(\pi)\nu\bar\nu$, and $B\to\pi\tau\nu$, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors…

High Energy Physics - Phenomenology · Physics 2016-02-16 Daping Du , A. X. El-Khadra , Steven Gottlieb , A. S. Kronfeld , J. Laiho , E. Lunghi , R. S. Van de Water , Ran Zhou

After a short presentation of the FLAG collaboration, we review lattice results related to pion, $K$-, $D$- and $B$-meson physics with the aim of making them easily accessible to the particle-physics community. Only a selection of FLAG…

High Energy Physics - Lattice · Physics 2015-09-04 Anastassios Vladikas

The Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$ is an important Standard Model parameter, whose value can be determined by using the semi-leptonic decay $B\rightarrow D^{*}\ell{\bar \nu}_\ell$. The perturbative QCD (pQCD)…

High Energy Physics - Phenomenology · Physics 2025-06-24 Wang Li , Xing-Gang Wu , Hua Zhou , Xu-Chang Zheng

We present a new lattice determination of some of the parameters appearing both in the Operator Product Expansion (OPE) analysis of the inclusive semileptonic $B$-meson decays and in the Heavy Quark Expansion (HQE) of the pseudoscalar (PS)…

High Energy Physics - Lattice · Physics 2018-04-18 Paolo Gambino , Aurora Melis , Silvano Simula

We present a lattice QCD determination of the vector and scalar form factors of the semileptonic $K \to \pi \ell \nu$ decay which are relevant for the extraction of the CKM matrix element $|V_{us}|$ from experimental data. Our results are…

High Energy Physics - Lattice · Physics 2017-09-26 N. Carrasco , P. Lami , V. Lubicz , L. Riggio , S. Simula , C. Tarantino

The rare kaon decays $K\to\pi\nu\bar{\nu}$ are strongly suppressed in the standard model and widely regarded as processes in which new phenomena, not predicted by the standard model, may be observed. Recognizing such new phenomena requires…

High Energy Physics - Lattice · Physics 2016-07-06 Norman H. Christ , Xu Feng , Antonin Portelli , Christopher T. Sachrajda

The Cabibbo-Kobayashi-Maskawa (CKM) matrix element $\vert V_{ub}\vert$ is obtained from exclusive semileptonic $B \to \pi \ell \nu_\ell$ and $B_s \to K \ell \nu_\ell$ decays adopting the unitarity-based dispersion matrix approach for the…

High Energy Physics - Phenomenology · Physics 2022-08-24 G. Martinelli , S. Simula , L. Vittorio

In the K and Bd systems, indirect CP violation is quantified by the parameters epsilon_K and sin 2beta respectively. Within the Standard Model, the uniqueness of the CP violating phase implies that the measurement of either between…

High Energy Physics - Phenomenology · Physics 2011-02-15 Diego Guadagnoli