Aimen Obaid

Aimen Obaid

Biography

Aimen Obaid is a rising senior at Smith College, double majoring in Physics and
Engineering. At Smith, she has pursued fundamental research through theoretical work in
quantum mechanics and experimental atomic physics. Last summer, she worked with Dr. Irene
Zoi through USCMS at Fermilab, implementing an analysis of vector boson scattering as a probe
of Higgs physics, deepening her appreciation for particle physics and motivating her senior
thesis. She spent her junior spring at Princeton University, exploring graduate-level high-energy
theory, strengthening her interest in pursuing a Ph.D. at the interface of precision measurement
and new physics. This summer, she’s working with Dr. Christoph Paus on the precision
measurement of the strong-coupling constant through Drell-Yan W-boson production at 5 TeV.
Raised in Lahore, Pakistan, she cares about science education access, women’s rights in South
Asia, and making fundamental physics feel less distant from the worlds that shaped her.

Measurement of αs (mW) using W± Boson Kinematics at √s = 5.02 TeV
Aimen Obaid1, David Walter2, Luca Lavezzo2, Christoph M. E. Paus2
1Department of Physics, Smith College
2Department of Physics, Massachusetts Institute of Technology

The strong coupling, αs, governs quantum chromodynamics and remains one of the least precisely
known Standard Model couplings. In Drell–Yan production, initial-state QCD radiation gives the vector
boson nonzero transverse momentum, making the low-pT spectrum sensitive to αs. This project develops
a 5 TeV W± analysis aimed at extracting αs(mW) from W → μν distributions and theoretical variations,
providing an independent constraint complementary to related vector-boson measurements. In W → μν
events, the neutrino transverse momentum is inferred from missing transverse momentum, allowing pT
W
to be reconstructed as the vector sum of the muon and neutrino transverse momenta. The analysis fits
pT
W distributions separated by W charge and muon pseudorapidity to templates generated with varied αs
values and parton-distribution-function variations. This work reconstructed the key W boson and muon
observables, propagated the theory variations into the fit inputs, validated the template-fitting framework,
and developed a data-driven estimate of the nonprompt muon background using control regions
in relative isolation and transverse impact parameter. These contributions establish the foundation for
the first W-based αs analysis at 5 TeV and strengthen future combined constraints across complementary
vector-boson measurements.