Parton distributions incorporating QED contributions
Abstract
We perform a global parton analysis of deep inelastic and related hard-scattering data, including {{mathcal{O}}}(α_QED) corrections to the parton evolution. Although the quality of the fit is essentially unchanged, there are two important physical consequences. First, the different DGLAP evolution of u and d type quarks introduces isospin violation, i.e. u^p neq d^n, which is found to be unambiguously in the direction to reduce the NuTeV sin^2θ_W anomaly. A second consequence is the appearance of photon parton distributions γ(x,Q^2) of the proton and the neutron. In principle these can be measured at HERA via the deep inelastic scattering processes e N to eγ X; our predictions are in agreement with the present data.
- Publication:
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European Physical Journal C
- Pub Date:
- February 2005
- DOI:
- 10.1140/epjc/s2004-02088-7
- arXiv:
- arXiv:hep-ph/0411040
- Bibcode:
- 2005EPJC...39..155M
- Keywords:
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- High Energy Physics - Phenomenology
- E-Print:
- 14 pages, 5 figures