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We provide a novel approach to calculate the gravitational form factor of pion under the ladder approximation of the Bethe-Salpeter equation, with contact interactions. Central to this approach is a symmetry-preserving treatment of the…

High Energy Physics - Phenomenology · Physics 2023-03-01 Zanbin Xing , Minghui Ding , Lei Chang

We calculate the scalar form factor of the pion using two dynamical flavors of non-perturbatively $\mathcal{O}(a)$-improved Wilson fermions, including both the connected and the disconnected contribution to the relevant correlation…

High Energy Physics - Lattice · Physics 2014-05-14 Vera Gülpers , Georg von Hippel , Hartmut Wittig

The electric dipole form factor of the nucleon stemming from the QCD $\bar{\theta}$ term is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud. Its momentum-dependence is…

Nuclear Theory · Physics 2009-11-11 W. H. Hockings , U. van Kolck

Strong coupling constant computed in Landau gauge and MOM renormalization scheme from lattice two and three gluon Green Functions exhibits an unexpected behavior in the deep IR, showing a maximum value around $1 {\rm GeV}$. We analise this…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ph. Boucaud , F. De Soto , A. Le Yaouanc , J. P. Leroy , J. Micheli , O. Pene , J. Rodriguez-Quintero

We analyze the interplay of topological objects in four-dimensional QCD on the lattice. The distributions of color magnetic monopoles in the maximum abelian gauge are computed around instantons in both pure and full QCD. We find an enhanced…

High Energy Physics - Lattice · Physics 2007-05-23 M. Feurstein , H. Markum , S. Thurner

Form factors for pions interactions with constituent quarks are investigated as the leading effective couplings obtained from a one loop background field method applied to a global color model. Two pion field definitions are considered and…

High Energy Physics - Phenomenology · Physics 2023-03-27 Fabio L. Braghin

We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of…

High Energy Physics - Phenomenology · Physics 2017-10-04 B. Ananthanarayan , Irinel Caprini , Diganta Das

We examine the contribution of small instantons to the axion mass in various UV completions of QCD. We show that the reason behind the potential dominance of such contributions is the non-trivial embedding of QCD into the UV theory. The…

High Energy Physics - Phenomenology · Physics 2020-02-19 Csaba Csaki , Maximilian Ruhdorfer , Yuri Shirman

We report a recent lattice-QCD calculation of nucleon and pion electromagnetic form factors and nucleon axial form factors, with special emphasis on large $Q^2$. Conventional lattice form-factor calculations can only reach about 2.5…

High Energy Physics - Lattice · Physics 2015-03-19 Huey-Wen Lin , Saul D. Cohen

Compact quantum electrodynamics (CQED$_3$) with Dirac fermionic matter provides an adequate framework for elucidating the universal low-energy physics of a wide variety of (2+1)D strongly correlated systems. Fractionalized states of matter…

Strongly Correlated Electrons · Physics 2021-07-20 G. Shankar , Joseph Maciejko

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 present an algorithm to compute correlation functions for systems with the quantum numbers of many identical mesons from lattice quantum chromodynamics (QCD). The algorithm is numerically stable and allows for the computation of $n$-pion…

Within the framework of the thermal soft-wall model of AdS/QCD, we investigate phenomenological properties of pions at finite temperature. This includes the electromagnetic (EM) form factor $F_{\pi}(Q^{2}, T)$, the thermal mass…

High Energy Physics - Phenomenology · Physics 2025-11-25 Narmin Nasibova , Xerxes D. Arsiwalla

The pion electromagnetic form factor has been calculated for the first time from the solutions of the Bethe-Salpeter equation, obtained directly in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter…

High Energy Physics - Phenomenology · Physics 2021-08-18 Emanuel Ydrefors , Wayne de Paula , Jorge H Alvarenga Nogueira , Tobias Frederico , Giovanni Salmé

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

Accessing hadronic form factors at large momentum transfers has traditionally presented a challenge for lattice QCD simulations. Here we demonstrate how a novel implementation of the Feynman-Hellmann method can be employed to calculate…

We extend a recent analysis of the pion electromagnetic form factor constrained by the conformal symmetry to explore the time-like region. We show explicitly that the time-like form factor obtained by the analytic continuation of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ho-Meoyng Choi , Chueng-Ryong Ji

We develop a method to compute the pion transition form factor directly at arbitrary space-like photon momenta and use it to determine the $\pi^0$-pole contribution to the hadronic light-by-light scattering in the anomalous magnetic moment…

High Energy Physics - Lattice · Physics 2025-07-31 Tian Lin , Mattia Bruno , Xu Feng , Lu-Chang Jin , Christoph Lehner , Chuan Liu , Qi-Yuan Luo

We propose a non-perturbative calculation scheme which is based on the semi-classical approximation of QCD and can be used to evaluate quantities of interest in hadronic physics. As a first application, we evaluate the mass of the pion and…

High Energy Physics - Phenomenology · Physics 2009-11-07 Pietro Faccioli