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Related papers: Pion form factor with twisted mass QCD

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Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of model-independent representations of the pion generalised parton distribution (GPD). Therewith, one arrives at a data-driven prediction for…

High Energy Physics - Phenomenology · Physics 2023-04-12 Yin-Zhen Xu , Khépani Raya , Zhu-Fang Cui , Craig D. Roberts , J. Rodríguez-Quintero

In a Poincare'-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a…

Nuclear Theory · Physics 2010-11-11 L. X. Gutierrez-Guerrero , A. Bashir , I. C. Cloet , C. D. Roberts

We present an update on our lattice calculations of the Mellin moments of PDFs and GPDs for the pion and kaon, using momentum-boosted meson states. In particular, we focus on the calculation of the scalar and tensor local operators, and the…

High Energy Physics - Lattice · Physics 2024-01-09 Joseph Delmar , Constantia Alexandrou , Simone Bacchio , Ian Cloët , Martha Constantinou , Giannis Koutsou

We consider how to extract the pion form factors in the epsilon regime. Using the correlators with non-zero momenta and taking appropriate ratios of them, we eliminate the dominant finite volume effect from the zero-momentum pion mode. Our…

High Energy Physics - Lattice · Physics 2012-11-06 JLQCD Collaboration , H. Fukaya , S. Aoki , S. Hashimoto , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada

We investigate wide-angle photo- and electroproduction of pions within the handbag mechanism in which the $\gamma^{(*)} N\to \pi N'$ amplitudes factorize into hard partonic subprocess amplitudes, $\gamma^{(*)} q\to \pi q'$, and form factors…

High Energy Physics - Phenomenology · Physics 2022-03-25 Peter Kroll , Kornelija Passek-Kumerički

We extend recently developed methods used for determining the electromagnetic charge radius and $a_\mu^{\pi\pi}$ to obtain a determination of the electromagnetic form factor of the pion, $F_\pi^V(t)$, in several significant kinematical…

High Energy Physics - Phenomenology · Physics 2019-01-02 B. Ananthanarayan , Irinel Caprini , Diganta Das

We analyze the higher-twist effects and the SU(3)-flavour symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for…

High Energy Physics - Phenomenology · Physics 2011-09-13 Johan Bijnens , Alexander Khodjamirian

By reanalysing transverse momentum dependence in the perturbative calculation of pion form factor an improved expression of pion form factor which takes into account the transverse momentum dependenc in hard scattering amplitude and…

High Energy Physics - Phenomenology · Physics 2009-10-30 Fu-Guang Cao , Tao Huang

Using Nf=2+1+1 lattice QCD, we determine the fermionic connected contributions to the second and third moment of the pion PDF. Based on gauge configurations from the European Twisted Mass Collaboration, chiral and continuum extrapolations…

High Energy Physics - Lattice · Physics 2021-02-22 M. Oehm , C. Alexandrou , M. Constantinou , K. Jansen , G. Koutsou , B. Kostrzewa , F. Steffens , C. Urbach , S. Zafeiropoulos

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…

We discuss the nonleading, ``soft" contribution to the pion form factor at intermediate momentum transfer within operator product expansion approach. We argue, that the corresponding contribution can temporarily {\bf simulate} the leading…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. Zhitnitsky

A global fit to the data from different collaborations (CELLO, CLEO, BaBar) on the pion-photon transition form factor is carried out using light-cone sum rules. The analysis includes the next-to-leading QCD radiative corrections and the…

High Energy Physics - Phenomenology · Physics 2012-01-17 A. P. Bakulev , S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

Using a holographic dual model of QCD, we compute the pion electromagnetic form factor F_pi(Q^2) in the spacelike momentum transfer region, as well as pion couplings to vector mesons g_rho^(n) pi pi. Spontaneous and explicit chiral symmetry…

High Energy Physics - Phenomenology · Physics 2008-11-26 Herry J. Kwee , Richard F. Lebed

We investigate the utility of partially twisted boundary conditions in lattice calculations of meson observables. For dynamical simulations, we show that the pion dispersion relation is modified by volume effects. In the isospin limit, we…

High Energy Physics - Lattice · Physics 2008-11-26 F. -J. Jiang , B. C. Tiburzi

We consider the pion-photon transition form factor at low to intermediate spacelike momenta within the theoretical framework of light-cone sum rules. We derive predictions which take into account all currently known contributions stemming…

High Energy Physics - Phenomenology · Physics 2017-03-24 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

We study the lattice cutoff ($a$) and quark mass dependences of pion masses and decay constants in the $N_f = 2$ twisted mass QCD, using the Wilson chiral perturbation theory to the next leading order (NLO). In order to investigate the…

High Energy Physics - Lattice · Physics 2011-11-02 Satoru Ueda , Sinya Aoki

We discuss the evaluation of the transition form factor (TFF) $F^{\gamma*\gamma\pi^0}(Q^2)$ by means of QCD theory and by state-space reconstruction from topological data analysis. We first calculate this quantity in terms of quark-gluon…

High Energy Physics - Phenomenology · Physics 2019-06-21 N. G. Stefanis

The pion electromagnetic form factor is calculated with a light-front quark model. The "plus" and "minus" component of the electromagnetic current are used to calculate the electromagnetic form factor in the Breit frame with two models for…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. P. B. C. de Melo

We present a detailed investigation of the spacelike pion's electromagnetic form factor using three-point QCD sum rules that exclusively involve nonlocal condensates. Our main methodological tools are a spectral density which includes…

High Energy Physics - Phenomenology · Physics 2009-06-25 A. P. Bakulev , A. V. Pimikov , N. G. Stefanis

We present an analysis of QCD sum rules for pion form factor in next-to-leading order of perturbation theory for the case of pseudoscalar pion currents. The essential instanton contribution is reanalysed with account for present more…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. V. Braguta , A. I. Onishchenko