Undergraduate Research at Jefferson Lab

Complete Calculations of Cross Sections and Asymmetries for Longitudinally and Transversely Polarized Leptons and Hadrons

Student: Paul Anderson

School: College of William and Mary

Mentored By: Douglas Higinbotham and Xiaochao Zheng

The electron-ion collider (EIC) will be the first ep collider capable of simultaneously polarizing the spin of both the leptons and hadrons. This opens the possibility for measurements of the nucleon spin structure and Parity-violating (PV) asymmetry in Deep Inelastic Scattering (DIS), for the first time, at a collider setting. Past DIS formalism developed for studies at Jefferson lab omitted electroweak contributions, while that developed for high energy ep colliders often omitted the mass of the hadrons and did not include transversely-polarized hadrons. Here, we complete the cross section calculation for DIS with both longitudinally and transversely polarized lepton and hadron. No approximation has been made, and all three contributions -γγ, γZ, and ZZ - are included. Our results are presented in terms of structure functions (F1, 2, 3 and g1, 2, 3, 4, 5), and can be directly compared with experimentally measured observables. We hope this work will establish the theoretical foundation needed for nucleon spin and parity violating DIS studies at the EIC.

[Watch the presentation on YouTube]