English
Related papers

Related papers: Matrix elements of the electromagnetic operator be…

200 papers

We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the ${\mathcal O}(a)$ improved current. We calculate form factor…

High Energy Physics - Lattice · Physics 2009-11-10 Jan van der Heide

We report the first lattice QCD computation of pion and kaon electromagnetic form factors, $F_M(Q^2)$, at large momentum transfer up to 10 and 28 $\mathrm{GeV}^2$, respectively. Utilizing physical masses and two fine lattices, we achieve…

High Energy Physics - Lattice · Physics 2025-02-14 Heng-Tong Ding , Xiang Gao , Andrew D. Hanlon , Swagato Mukherjee , Peter Petreczky , Qi Shi , Sergey Syritsyn , Rui Zhang , Yong Zhao

We determine the light quark masses from lattice QCD simulations incorporating the electromagnetic interaction of valence quarks. The meson masses are calculated on lattice QCD configurations generated by the RBC Collaboration for two…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas Blum , Takumi Doi , Masashi Hayakawa , Taku Izubuchi , Norikazu Yamada

We presents results for the matrix elements of a variety of four-fermion operators calculated using quenched Wilson fermions. Our simulations are done on 170 lattices of size $32^3 x 64$ at $\beta = 6.0$. We find $B_K=0.74 +- 0.04 +- 0.05$,…

High Energy Physics - Lattice · Physics 2008-02-03 Rajan Gupta , Tanmoy Bhattacharya , Stephen Sharpe

Measurements and theoretical calculations of meson form factors are essential for our understanding of internal hadron structure and QCD, the dynamics that bind the quarks in hadrons. The pion electromagnetic form factor has been measured…

High Energy Physics - Lattice · Physics 2018-04-18 Jonna Koponen , André Zimermmane-Santos , Christine Davies , G. Peter Lepage , Andrew Lytle

We report on our calculation of the kaon semileptonic form factors in Nf=2+1 lattice QCD. Chiral symmetry is exactly preserved by using the overlap quark action for a straightforward comparison with chiral perturbation theory (ChPT). We…

High Energy Physics - Lattice · Physics 2011-12-23 JLQCD Collaboration , T. Kaneko , S. Aoki , G. Cossu , X. Feng , H. Fukaya , S. Hashimoto , J. Noaki , T. Onogi

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

We present results for matrix elements of $\Delta S=2$ four-fermion operators arising generically in models of new physics. These are needed to constrain such models using the measured values of $\varepsilon_K$ and $\Delta M_K$. We use…

We present non-perturbative results for beyond the standard model kaon mixing matrix elements in the isospin symmetric limit ($m_u=m_d$) of QCD, including a complete estimate of all dominant sources of systematic error. Our results are…

High Energy Physics - Lattice · Physics 2024-04-04 Peter A. Boyle , Felix Erben , Jonathan M. Flynn , Nicolas Garron , Julia Kettle , Rajnandini Mukherjee , J. Tobias Tsang

We compute the electromagnetic form factor of a "pion" with mass m_pi=330MeV at low values of Q^2\equiv -q^2, where q is the momentum transfer. The computations are performed in a lattice simulation using an ensemble of the RBC/UKQCD…

High Energy Physics - Lattice · Physics 2009-01-06 P. A. Boyle , J. M. Flynn , A. Juttner , C. Kelly , H. Pedroso de Lima , C. M. Maynard , C. T. Sachrajda , J. M. Zanotti

Hadronic matrix elements of proton decay are essential ingredients to bridge the grand unification theory to low energy observables like proton lifetime. In this paper we non-perturbatively calculate the matrix elements, relevant for the…

High Energy Physics - Lattice · Physics 2014-01-22 Y. Aoki , E. Shintani , A. Soni

We present preliminary results of the first lattice QCD calculation of the K -> pi matrix elements of the chromomagnetic operator O_{CM}=g sbar sigma_{munu} G_{munu} d, which appears in the effective Hamiltonian describing Delta S=1…

High Energy Physics - Lattice · Physics 2015-09-02 M. Constantinou , M. Costa , R. Frezzotti , V. Lubicz , G. Martinelli , D. Meloni , H. Panagopoulos , S. Simula

The pion electromagnetic form factor is calculated at lower and higher momentum transfer in order to explore constituent quark models and the differences among those models. In particular, the light-front constituent quark model is utilized…

High Energy Physics - Phenomenology · Physics 2016-10-19 J. P. B. C. de Melo , Rômulo Moreira Moita , Kazuo Tsushima

The QCDSF/UKQCD collaboration has an ongoing program to calculate nucleon matrix elements with two flavours of dynamical O(a) improved Wilson fermions. Here we present recent results on the electromagnetic form factors, the quark momentum…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , Ph. Hägler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers , H. Stüben , J. M. Zanotti

We present updated results for the nucleon axial charge and electromagnetic (EM) form factors, which include a significant increase in statistics for all ensembles (up to 4000 measurements), as well as the addition of ensembles with pion…

High Energy Physics - Lattice · Physics 2014-04-09 B. Jäger , T. D. Rae , S. Capitani , M. Della Morte , D. Djukanovic , G. von Hippel , B. Knippschild , H. B. Meyer , H. Wittig

We present our preliminary results concerning the charged/neutral pion mass difference $M_{\pi^{+}} - M_{\pi^{0}}$ at order $\mathcal{O}(\alpha_{em})$ in the QED interactions, and for $M_{\pi^{+}} - M_{\pi^{0}}$ at order $\mathcal{O}\left(…

High Energy Physics - Lattice · Physics 2021-12-03 R. Frezzotti , G. Gagliardi , V. Lubicz , G. Martinelli , F. Sanfilippo , S. Simula

We compute the hadronic matrix elements of the four-quark operators needed for the study of neutral kaon mixing beyond the Standard Model (SM). We use nf=2+1 flavours of domain-wall fermions (DWF) which exhibit good chiral-flavour symmetry.…

High Energy Physics - Lattice · Physics 2012-10-05 P. A. Boyle , N. Garron , R. J. Hudspith

The charged and neutral kaon form factors are calculated as a phenomenological application of the QCD Dyson-Schwinger equations. The results are compared with the pion form factor calculated in the same framework and yield…

Nuclear Theory · Physics 2010-03-04 C. J. Burden , C. D. Roberts , M. J. Thomson

We present the current status of our lattice calculation of the electromagnetic form factor of the pion with two flavours of non-perturbatively O(a)-improved Wilson fermions. Using twisted boundary conditions and stochastic sources we…

High Energy Physics - Lattice · Physics 2013-01-17 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We present the first unquenched, continuum limit, lattice QCD results for the matrix elements of the operators describing neutral kaon oscillations in extensions of the Standard Model. Owing to the accuracy of our calculation on \Delta S=2…