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相关论文: Lattice QCD calculation of $K\to \ell\nu_\ell \ell…

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A precise SM prediction for the direct CP violation in the $K \rightarrow \pi\pi$ decay process is of great importance in confronting experiments and constraining new physics. The state-of-art lattice QCD study of this process will soon…

高能物理 - 格点 · 物理学 2018-12-31 Yiming Cai , Zohreh Davoudi

The rare decays of a kaon into a pion and a charged lepton/antilepton pair proceed via a flavour changing neutral current and therefore may only be induced beyond tree level in the Standard Model. This natural suppression makes these decays…

高能物理 - 格点 · 物理学 2017-04-04 Norman H. Christ , Xu Feng , Andreas Juttner , Andrew Lawson , Antonin Portelli , Christopher T. Sachrajda

We explore application of the domain wall fermion formalism of lattice QCD to calculate the $K\to\pi\pi$ decay amplitudes in terms of the $K\to\pi$ and $K\to 0$ hadronic matrix elements through relations derived in chiral perturbation…

We present a lattice-QCD calculation of the $B\to\pi\ell\nu$ semileptonic form factors and a new determination of the CKM matrix element $|V_{ub}|$. We use the MILC asqtad 2+1-flavor lattice configurations at four lattice spacings and…

We calculate the logarithmic corrections to the matrix elements for $K^+\to\pi^+$ and $K\to$vacuum (which are used on the lattice to determine $K\to\pi\pi$ amplitudes), in one-loop quenched and unquenched Chiral Perturbation Theory. We find…

高能物理 - 格点 · 物理学 2015-06-25 Maarten Golterman , Elisabetta Pallante

In this project, we will compute the form factors relevant for $B \to K^*(\to K \pi)\ell^+\ell^-$ decays. To map the finite-volume matrix elements computed on the lattice to the infinite-volume $B \to K \pi$ matrix elements, the $K \pi$…

We evaluate energy levels of the K-pi system in the K* channel in finite volume using chiral unitary theory. We use these energy levels to obtain K-pi phase shifts, and then obtain the K* mass and its decay width. We investigate their…

高能物理 - 格点 · 物理学 2015-05-15 Dan Zhou , Er-Liang Cui , Hua-Xing Chen , Li-Sheng Geng , Li-Hua Zhu

We discuss finite-volume computations of two-body hadronic decays below the inelastic threshold (e.g. $K\to\pi\pi$ decays). The relation between finite-volume matrix elements and physical amplitudes, recently derived by Lellouch and…

高能物理 - 格点 · 物理学 2008-11-26 C. -J. D. Lin , G. Martinelli , C. T. Sachrajda , M. Testa

We present a lattice QCD calculation of the form factors and differential decay rates for semileptonic decays of the heavy-light mesons $B$ and $D$ to the final state $\pi l\nu$. The results are obtained with three methodological…

高能物理 - 唯象学 · 物理学 2010-11-19 Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie , Sinead M. Ryan , James N. Simone

We propose a lattice-QCD-suitable framework for computing the two-photon long-distance contribution to the complex $K_{\rm L}\rightarrow\mu^+\mu^-$ decay amplitude, where QED is treated perturbatively in the continuum and infinite-volume.…

高能物理 - 格点 · 物理学 2023-12-22 En-Hung Chao , Norman H. Christ , Xu Feng , Luchang Jin

Dilepton decays of pseudoscalar mesons have been drawing particular interest, thanks to their sensitivity to both the QCD dynamics at low energy and also signals beyond the Standard Model. In this context, we shortly review our recent study…

高能物理 - 格点 · 物理学 2023-12-04 Bai-Long Hoid , Martin Hoferichter , Jacobo Ruiz de Elvira

We report a first, complete lattice QCD calculation of the long-distance contribution to the $K^+\to\pi^+\nu\bar{\nu}$ decay within the standard model. This is a second-order weak process involving two four-Fermi operators that is highly…

高能物理 - 格点 · 物理学 2017-06-28 Ziyuan Bai , Norman H. Christ , Xu Feng , Andrew Lawson , Antonin Portelli , Christopher T. Sachrajda

We present a lattice calculation of the electromagnetic (EM) effects on the masses of light pseudoscalar mesons. The simulations employ 2+1 dynamical flavors of asqtad QCD quarks, and quenched photons. Lattice spacings vary from $\approx…

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…

高能物理 - 格点 · 物理学 2017-09-26 N. Carrasco , P. Lami , V. Lubicz , L. Riggio , S. Simula , C. Tarantino

We present our result for the $K\to\pi\pi$ decay amplitudes for both the $\Delta I=1/2$ and $3/2$ processes with the improved Wilson fermion action. In order to realize the physical kinematics, where the pions in the final state have finite…

高能物理 - 格点 · 物理学 2018-12-26 N. Ishizuka , K. -I. Ishikawa , A. Ukawa , T. Yoshié

We report a direct lattice calculation of the $K$ to $\pi\pi$ decay matrix elements for both $\Delta I=1/2$ and $3/2$ channels on 2+1 flavor, domain wall fermion, $16^3\times32$ lattices with zero $\pi\pi$ relative momentum and $m_\pi=420$…

高能物理 - 格点 · 物理学 2011-02-18 Qi Liu , RBC , UKQCD collaborations

We use one-loop chiral perturbation theory to compare potential lattice computations of the K+ --> pi+ pi0 decay amplitude at m_K=2m_pi with the experimental value. We find that the combined one-loop effect due to this unphysical pion to…

高能物理 - 格点 · 物理学 2016-08-25 Maarten F. L. Golterman , Ka Chun Leung

We develop a strategy for computing the $B\to K\ell^+\ell^-$ and $\bar{B}_s\to\gamma\ell^+\ell^-$ decay amplitudes using lattice QCD (where $\ell^\pm$ are charged leptons). We focus on those terms which contain complex contributions to the…

高能物理 - 格点 · 物理学 2026-03-24 R. Frezzotti , G. Gagliardi , V. Lubicz , G. Martinelli , C. T. Sachrajda , F. Sanfilippo , L. Silvestrini , S. Simula , N. Tantalo

We present the results of our lattice QCD study of the $g_{D^* D\pi}i$ coupling, relevant to the $D^\ast \to D\pi$ decay. Our computation is made on the gauge field configurations that include $N_f=2$ dynamical light quarks by using the…

高能物理 - 格点 · 物理学 2015-06-11 Damir Becirevic , Francesco Sanfilippo

We calculate the form factors for the $B \to D^*\ell\nu_\ell$ decay in 2+1 flavor lattice QCD. For all quark flavors, we employ the M\"obius domain-wall action, which preserves chiral symmetry to a good precision. Our gauge ensembles are…

高能物理 - 格点 · 物理学 2024-06-05 Y. Aoki , B. Colquhoun , H. Fukaya , S. Hashimoto , T. Kaneko , R. Kellermann , J. Koponen , E. Kou