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arXiv · 1306.6073

Anatomy of relativistic pion loop corrections to the electromagnetic nucleon coupling

Chueng-Ryong Ji·W. Melnitchouk·A. W. Thomas
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Abstract

We present a relativistic formulation of pion loop corrections to the coupling of photons with nucleons on the light-front. Vertex and wave function renormalization constants are computed to lowest order in the pion field, including their nonanalytic behavior in the chiral limit, and studied numerically as a function of the ultraviolet cutoff. Particular care is taken to explicitly verify gauge invariance and Ward-Takahashi identity constraints to all orders in the m_pi expansion. The results are used to compute the chiral corrections to matrix elements of local operators, related to moments of deep-inelastic structure functions. Finally, comparisons of results for pseudovector and pseudoscalar coupling allows the resolution of a long-standing puzzle in the computation of pion cloud corrections to structure function moments.

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Chueng-Ryong Ji, W. Melnitchouk, A. W. Thomas. 2013-06-25. Anatomy of relativistic pion loop corrections to the electromagnetic nucleon coupling. https://doi.org/10.1103/physrevd.88.076005

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