Ad Lucem: QED parton distribution functions in the MMHT framework

Harland-Lang, L.A.; Martin, A.D.; Nathvani, R.; Thorne, R.S.

Abstract

We present the MMHT2015qed PDF set, resulting from the inclusion of QED corrections to the existing set of MMHT Parton Distribution Functions (PDFs), and which contain the photon PDF of the proton. Adopting an input distribution from the LUXqed formulation, we discuss our methods of including QED effects for the full, coupled DGLAP evolution of all partons with QED at O(α) , O(ααS) , O(α2) . While we find consistency for the photon PDF of the proton with other recent sets, building on this we also present a set of QED corrected neutron PDFs and provide the photon PDF separated into its elastic and inelastic contributions. The effect of QED corrections on the other partons and the fit quality is investigated, and the sources of uncertainty for the photon are outlined. Finally we explore the phenomenological implications of this set, giving the partonic luminosities for both the elastic and inelastic contributions to the photon and the effect of our photon PDF on fits to high mass Drell–Yan production, including the photon-initiated channel.

Citation

Harland-Lang, L., Martin, A., Nathvani, R., & Thorne, R. (2019). Ad Lucem: QED parton distribution functions in the MMHT framework. The European Physical Journal C, 79(10), Article 811. https://doi.org/10.1140/epjc/s10052-019-7296-0

• Journal Article Type: Article
• Acceptance Date: Sep 2, 2019
• Online Publication Date: Oct 1, 2019
• Publication Date: Oct 31, 2019
• Deposit Date: Oct 11, 2019
• Publicly Available Date: Oct 11, 2019
• Journal: European Physical Journal C: Particles and Fields
• Print ISSN: 1434-6044
• Electronic ISSN: 1434-6052
• Publisher: SpringerOpen
• Peer Reviewed: Peer Reviewed
• Volume: 79
• Issue: 10
• Article Number: 811
• DOI: https://doi.org/10.1140/epjc/s10052-019-7296-0
• Public URL: https://durham-repository.worktribe.com/output/1288659