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arXiv · 2207.04339

Pion scalar, vector and tensor form factors from a contact interaction

Xiaobin Wang·Zanbin Xing·Jiayin Kang·Khépani Raya·Lei Chang
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Abstract

The pion scalar, vector and tensor form factors are calculated within a symmetry-preserving contact interaction model (CI) of quantum chromodynamics (QCD), encompassed within a Dyson-Schwinger and Bethe-Salpeter equations approach. In addition to the traditional rainbow-ladder truncation, a modified interaction kernel for the Bethe-Salpeter equation is adopted. The implemented kernel preserves the vector and axial-vector Ward-Takahashi identities, while also providing additional freedom. Consequently, new tensor structures are generated in the corresponding interaction vertices, shifting the location of the mass poles appearing in the quark-photon and quark tensor vertex and yielding a notorious improvement in the final results. Despite the simplicity of the CI, the computed form factors and radii are compatible with recent lattice QCD simulations.

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Xiaobin Wang, Zanbin Xing, Jiayin Kang, Khépani Raya, Lei Chang. 2022-07-09. Pion scalar, vector and tensor form factors from a contact interaction. https://doi.org/10.1103/physrevd.106.054016

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