6th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan
Sunday–Friday, November 26–December 1 2023;
Hawaii, the Big Island
Session E06: Minisymposium: 3D Nucleon Structure II
7:00 PM–8:45 PM,
Wednesday, November 29, 2023
Hilton Waikoloa Village
Room: Queens 5
Chair: Alexei Prokudin, Penn State Berks
Abstract: E06.00003 : Impact of QED Effects in SIDIS: A New Hybrid Factorization Approach
7:30 PM–7:45 PM
Abstract
Presenter:
Justin Cammarota
(William & Mary)
Authors:
Justin Cammarota
(William & Mary)
Jianwei Qiu
(Jefferson Lab/Jefferson Science Associat)
Nobuo Sato
(Jefferson Lab)
The factorization theorem plays an important role in the analysis of high energy quantum chromodynamic (QCD) processes, separating the nonperturbative hadronic interaction into the universal parton distribution functions (PDFs) and fragmentation functions (FFs) and the process-dependent interactions into short distance perturbative calculations, with any interference power suppressed. With a virtual photon exchange, lepton-hadron deep inelastic scattering (DIS) provides an electromagnetic hard probe for the partonic structure of colliding hadron and has played an important role in the development of QCD factorization. However, the collision induced QED radiation can change the momentum of the exchanged but unobserved virtual photon, making the photon-hadron frame, where the factorization formalism for DIS and semi-inclusive DIS (SIDIS) was derived, ill defined. An new analogous factorization approach has been introduced to separate the leading power process-independent QED radiative contributions to the single photon exchange by introducing global lepton distribution functions (LDFs) and lepton fragmentation functions (LFFs), while process-dependent effects are perturbatively calculated with large logarithms removed [J. High Energ. Phys. 2021, 157 (2021)]. These LDFs and LFFs appear in many different interactions, such as e+ e-, DIS and SIDIS. In this talk, I will apply this new hybrid factorization approach to lepton-hadron SIDIS to study the cross-section in two different kinematic regions: (1) the final state lepton and hadron are close to back-to-back, and (2) they are not, where collinear QCD factorization works for (2) and TMD QCD factorization for (1) while collinear QED factorization works for both. I show the effects on the SIDIS cross section using fixed order calculations for the unpolarized structure function by first showing the effect of the radiative corrections on the main kinematic variables, especially how the internal transverse momentum is significantly correlated to the external angular dependence, and then the unpolarized structure function (or cross section) with matching between the descriptions for low and high transverse momentum, using the MAP model for the TMDs and the JAM parameterization for the collinear QCD functions.