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Related papers: Kl3 and pion form factors using partially twisted …

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We apply the background field method to calculate the moments of the pion two-particles twist-3 distribution amplitude (DA) $\phi_p(\xi)$ in QCD sum rules. In this paper,we do not use the equation of motion for the quarks inside the pion…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tao Huang , Xing-Hua Wu , Ming-Zhen Zhou

We present the results of the calculation of the Kl3 semileptonic form factor at zero momentum transfer, f(0), obtained at one-loop in partially quenched Chiral Perturbation Theory (with either Nf=2, or Nf=3, and with generic valence and…

High Energy Physics - Lattice · Physics 2009-11-11 Damir Becirevic , Guido Martinelli , Giovanni Villadoro

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 present a comprehensive analysis of the electromagnetic form factors of the nucleon from a lattice simulation with two flavors of dynamical O(a)-improved Wilson fermions. A key feature of our calculation is that we make use of an…

We present lattice QCD calculations of nucleon electromagnetic form factors using pion masses $m_\pi$ = 149, 202, and 254 MeV and an action with clover-improved Wilson quarks coupled to smeared gauge fields, as used by the…

High Energy Physics - Lattice · Physics 2014-11-20 J. R. Green , J. W. Negele , A. V. Pochinsky , S. N. Syritsyn , M. Engelhardt , S. Krieg

New, accurate measurements of the pion and kaon electromagnetic form factors are expected in the near future from experiments at electron-positron colliders,using the radiative return method. We construct a model for the timelike pion…

High Energy Physics - Phenomenology · Physics 2015-06-25 Christine Bruch , Alexander Khodjamirian , Johann H. Kuhn

We present a calculation of the scalar, vector, and tensor form factors for the pion and kaon in lattice QCD. We use an ensemble of two degenerate light, a strange and a charm quark ($N_f=2+1+1$) of maximally twisted mass fermions with…

The form factor for the anomalous process $\gamma \pi ^* \to \pi \pi$, $F^{3\pi}(s,t,u)$, is calculated as a phenomenological application of the QCD Dyson-Schwinger equations. The chiral-limit value dictated by the electromagnetic,…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Alkofer , C. D. Roberts

Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $\chi$PT…

High Energy Physics - Theory · Physics 2025-08-11 Yifei He , Martin Kruczenski

The gravitational form factors (GFFs) of pions are calculated from a top-down holographic quantum chromodynamics (QCD) approach with momentum transfer dependence for the first time. It is important because the GFFs of hadrons have…

High Energy Physics - Phenomenology · Physics 2024-11-13 Daisuke Fujii , Akihiro Iwanaka , Mitsuru Tanaka

We study the form factors of the low energy anomalous pion-2-photon and photon-3-pion processes in the nonlocal chiral quark model which incorporates the momentum dependence of the dynamical quark mass and realizes correctly the chiral…

High Energy Physics - Phenomenology · Physics 2009-11-07 Xiaoyuan Li , Yi Liao

The anapole form factor of the nucleon is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud, and is proportional to the non-derivative parity-violating pion-nucleon…

High Energy Physics - Phenomenology · Physics 2009-10-31 C. M. Maekawa , U. van Kolck

We perform a new calculation of the hadronic contributions, $a({\rm Hadronic})$ to the anomalous magnetic moment of the muon, $a_\mu$. For the low energy contributions of order $\alpha^2$ we carry over an analysis of the pion form factor…

High Energy Physics - Phenomenology · Physics 2009-11-07 J. F. de Troconiz , F. J. Yndurain

Some predictions concerning possible results of the future JLab experiments on the pion form factor F_pi(Q^2) are made. The calculations exploit the method proposed previously by the authors and based on the instant-form Poincare invariant…

Nuclear Theory · Physics 2009-12-14 A. F. Krutov , V. E. Troitsky , N. A. Tsirova

We examine the quark mass dependence of the pion vector form factor, particularly the curvature (mean quartic radius). We focus our study on the consequences of assuming that the coupling constant of the rho to pions is largely independent…

High Energy Physics - Phenomenology · Physics 2010-01-08 Feng-Kun Guo , Christoph Hanhart , Felipe J. Llanes-Estrada , Ulf-G. Meißner

The off--shell electromagnetic vertex function of pions and kaons is studied in a bosonized Nambu--Jona-Lasinio model with a gauge--invariant proper--time cutoff. The slope of the pion form factor with respect to the pion 4--momentum is…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. Weiss

The elastic and $\gamma \to \pi$ transition form factors of the pion along with its usual static observables are calculated within a light-front field approach to the constituent quark model. The focus of this exercise in a simple model is…

Nuclear Theory · Physics 2015-06-18 J. P. B. C. de Melo , B. El-Bennich , T. Frederico

The data analysis for the reaction H(e,e' pi^+)n, which was used to determine values for the charged pion form factor Fpi for values of Q^2=0.6-1.6 GeV^2, has been repeated with careful inspection of all steps and special attention to…

The spin-independent and transversity generalised form factors (GFFs) of the $\phi$ meson are studied using lattice QCD calculations with light quark masses corresponding to a pion mass $m_\pi\sim450(5)$ MeV. One transversity and three…

High Energy Physics - Lattice · Physics 2019-01-17 W. Detmold , D. Pefkou , P. E. Shanahan

Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge…

Nuclear Experiment · Physics 2009-04-15 J. Volmer
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