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Related papers: Structure Functions, Form Factors, and Lattice QCD

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We present the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits the pion. These deviations…

High Energy Physics - Lattice · Physics 2017-10-23 Jonna Koponen , Francis Bursa , Christine T. H. Davies , Rachel J. Dowdall , G. Peter Lepage

We show how to compute electromagnetic polarizabilities of charged hadrons using four-point functions in lattice QCD. The low-energy behavior of Compton scattering amplitude is matched to matrix elements of current-current correlation…

High Energy Physics - Lattice · Physics 2022-01-03 Walter Wilcox , Frank X. Lee

We present a formula that allows one to calculate the pion form factor in the timelike region 2mpi <= sqrt{s} <= 4mpi in lattice QCD. The form factor quantifies the contribution of two-pion states to the vacuum polarization. It must be…

High Energy Physics - Lattice · Physics 2012-04-04 Harvey B. Meyer

We present preliminary results from the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits…

High Energy Physics - Lattice · Physics 2013-11-15 Jonna Koponen , Francis Bursa , Christine Davies , Gordon Donald , Rachel Dowdall

We study the electric polarizability of a charged kaon from four-point functions in lattice QCD as an alternative to the background field method. Lattice four-point correlation functions are constructed from quark and gluon fields to be…

High Energy Physics - Lattice · Physics 2025-03-07 Shayan Nadeem , Walter Wilcox , Frank X. Lee

We present a comprehensive study of the electromagnetic form factor, the decay constant and the mass of the pion computed in lattice QCD with two degenerate O(a)-improved Wilson quarks at three different lattice spacings in the range…

High Energy Physics - Lattice · Physics 2015-06-16 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We report a proof-of-principle lattice QCD simulation of the electric and magnetic polarizabilities for a neutral pion in the four-point function method. The results are based on the same quenched Wilson ensembles on a $24^3\times 48$…

High Energy Physics - Lattice · Physics 2024-10-11 Frank X. Lee , Walter Wilcox , Andrei Alexandru , Chris Culver , Shayan Nadeem

We report on the lowest moment of parton distribution functions and generalized form factors for the pion at several values of the momentum transfer. Calculations are performed for N_f=2 flavors of O(a) improved Wilson fermions with pion…

High Energy Physics - Lattice · Physics 2013-12-02 G. Bali , S. Collins , B. Glässle , M. Göckeler , N. Javadi-Motaghi , J. Najjar , W. Söldner , A. Sternbeck

We present a lattice QCD calculation of the electric polarizability of the charged kaon using a four-point function approach, which is the Euclidean analog of low-energy Compton scattering. In the case of the charged kaon, the…

High Energy Physics - Lattice · Physics 2026-04-16 Shayan Nadeem , Walter Wilcox , Frank X. Lee

Polarizabilities reveal valuable information on the internal structure of hadrons in terms of charge and current distributions. For neutral hadrons, the standard approach is the background field method. But for a charged hadron, its…

High Energy Physics - Lattice · Physics 2023-08-02 Frank X. Lee , Andrei Alexandru , Chris Culver , Walter Wilcox

We report on our exploratory study for the direct evaluation of the parton distribution functions from lattice QCD, based on a recently proposed new approach. We present encouraging results using Nf = 2 + 1 + 1 twisted mass fermions with a…

We present a lattice QCD calculation of the pion scalar form factor and associated radii with fully controlled systematics. Lattice results are computed on a large set of 17 gauge ensembles with $N_f=2+1$ Wilson Clover-improved sea quarks.…

High Energy Physics - Lattice · Physics 2025-03-27 Konstantin Ottnad , Georg von Hippel

We report a first principle lattice calculation of the pion electric polarizability $\alpha_\pi$ at the physical pion mass. First, we derive the master formula, which relates the pion polarizabilities with the position space hadronic…

High Energy Physics - Lattice · Physics 2022-01-06 Xu Feng , Taku Izubuchi , Luchang Jin , Maarten Golterman

We calculate the lower moments of the deep-inelastic structure functions of the pion and the rho meson on the lattice. Of particular interest to us are the spin-dependent structure functions of the rho. The calculations are done with Wilson…

High Energy Physics - Lattice · Physics 2008-11-26 C. Best , M. Göckeler , R. Horsley , E. -M. Ilgenfritz , H. Perlt , P. Rakow , A. Schäfer , G. Schierholz , A. Schiller , S. Schramm

Results for Monte Carlo calculations of the electromagnetic vector and scalar form factors of the pion in a quenched simulation are presented. We work with two different lattice volumes up to a spatial size of 2.4 fm at a lattice spacing of…

High Energy Physics - Lattice · Physics 2008-11-26 Stefano Capitani , Christof Gattringer , C. B. Lang

We compute structure functions in the Hamiltonian formalism on a momentum lattice using a physically motivated regularisation that links the maximal parton number to the lattice size. We show for the $\phi ^4 _{3+1}$ theory that our method…

High Energy Physics - Lattice · Physics 2007-05-23 Helmut Kroger , Norbert Scheu

Moments of generalised parton distributions can be related to off-forward matrix elements of local operators. We calculate a few of the leading twist matrix elements for the pion on the lattice. The simulations are performed using two…

High Energy Physics - Lattice · Physics 2008-11-26 D. Brömmel , M. Diehl , M. Göckeler , Ph. Hägler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , J. M. Zanotti

We study the electromagnetic structure of the pion in terms of the quantum cromodynamic~(QCD) model on the Breit-frame. We calculated the observables, such as the electromagnetic form factor. The priori to have a calculation covariant need…

High Energy Physics - Phenomenology · Physics 2016-05-17 Clayton Santos Mello , J. P. B. C. de Melo , T. Frederico

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 suggest to compute structure functions in the Hamiltonian formalism on a momentum lattice using a physically motivated regularisation that links the total parton number to the lattice size. We show for the $\phi ^4 _4$ theory that our…

Quantum Physics · Physics 2009-09-25 Norbert Scheu