Photon structure function

The photon structure function, in quantum field theory, describes the quark content of the photon. While the photon is a massless boson, through certain processes its energy can be converted into the mass of massive fermions. The function is defined by the process e + γ → e + hadrons. It is uniquely characterized by the linear increase in the logarithm of the electronic momentum transfer log Q2 and by the approximately linear rise in x , the fraction of the quark momenta within the photon. These characteristics are borne out by the experimental analyses of the photon structure function. rdf:langString