A Model for the Pion Structure Function
نویسنده
چکیده
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward γπ → γπ scattering amplitude is evaluated and related to the structure functions. It is shown that the introduction of nonperturbative effects, linked to the size of the pion and preserving gauge invariance, allows a connection with the quark distribution. It is predicted that higher-twist terms become negligible for Q larger than ∼2 GeV and that quarks in the pion have a momentum fraction smaller than in the proton case.
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