What if a tiny difference in the way particles scatter could reveal a new force—or even a particle we have never seen before? The Standard Model provides our best description of the visible universe, yet it cannot explain dark matter, motivating increasingly precise tests of its predictions. In this talk, I will explore what happens when beams of electrons or other leptons scatter from protons. Because of the weak force, particles with opposite spin orientations scatter at slightly different rates, producing what is known as a parity-violating asymmetry. I will show how to calculate this subtle effect, starting with a simple picture and building toward the precision required by modern experiments. Experiments including Qweak, P2, the Electron-Ion Collider (EIC), MOLLER, and MUSE will provide increasingly sensitive tests of these predictions. A persistent discrepancy between theory and experiment could offer a glimpse of new particles or interactions, including possibilities connected to a hidden or dark sector of the universe.
Dr. Mahumm Ghaffar is a postdoctoral fellow at Memorial University’s Grenfell Campus, where she also completed her PhD in theoretical subatomic physics. Originally from Pakistan, she is building her academic career in Newfoundland while raising a family. She also completed an intensive one-year diploma in High Energy Physics at the International Centre for Theoretical Physics (ICTP) in Trieste, Italy. Her research focuses on precision tests of the Standard Model, particularly electroweak radiative corrections and parity-violating processes. Passionate about making physics accessible and inspiring, she is also a Let’s Talk Science volunteer, where she enjoys engaging young learners and sharing her enthusiasm for physics.