Photon parton distributions in nuclei and the EMC effect

L. Frankfurt, M. Strikman

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Photons, as well as quarks and gluons, are constituents of the infinite momentum frame (IMF) wave function of an energetic particle. They are mostly equivalent photons whose amplitude follows from the Lorentz transformation of the particle rest frame Coulomb field into the IMF and from the conservation of the electromagnetic current. We evaluate in a model independent way the dominant photon contribution αem(Z2/A4⊃/3)ln(1/RAm Nx) to the nuclear structure functions as well as the term αemZ/A. In addition we show that the definition of x consistent with the exact kinematics of eA scattering (with exact sum rules) works in the same direction as the nucleus field of equivalent photons. Combined, these effects account for the bulk of the hadronic European Muon Collaboration (EMC) effect for x≤0.5 where Fermi motion effects are small. In particular, for these x the hadronic mechanism contribution to the EMC effect does not exceed ∼3% for all nuclei. Also, the A dependence of the hadronic mechanism of the EMC effect for x>0.5 is significantly modified.

Original languageEnglish (US)
Article number065203
JournalPhysical Review C - Nuclear Physics
Volume82
Issue number6
DOIs
StatePublished - Dec 15 2010

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics

Cite this