Phiala Shanahan

About

Phiala E. Shanahan is an Associate Professor of Physics at MIT, with research focused on particle and nuclear theory, particularly understanding the structure and interactions of hadrons and nuclei from the fundamental quark and gluon degrees of freedom encoded in the Standard Model of particle physics. Her recent work has concentrated on the role of gluons in hadron and nuclear structure, utilizing analytic tools and high-performance supercomputing to achieve the first calculation of the gluon structure of light nuclei, making predictions testable in upcoming experiments at Jefferson National Accelerator Facility and the Electron-Ion Collider. She has also extensively studied the role of strange quarks in the proton and light nuclei, sharpening theoretical predictions for dark matter cross-sections in direct detection experiments. To address computational limitations in quantum chromodynamics calculations, she is integrating modern machine learning techniques into computational nuclear physics studies.

Research topics

• Physics
• Particle physics
• Computer Science
• Astronomy
• Statistical physics
• Nuclear physics
• Theoretical physics

Selected publications

• Equivariant Flow-Based Sampling for Lattice Gauge Theory

  Physical Review Letters · 2020-09-15 · 198 citations

  articleOpen accessSenior author

  We define a class of machine-learned flow-based sampling algorithms for lattice gauge theories that are gauge invariant by construction. We demonstrate the application of this framework to U(1) gauge theory in two spacetime dimensions, and find that, at small bare coupling, the approach is orders of magnitude more efficient at sampling topological quantities than more traditional sampling procedures such as hybrid Monte Carlo and heat bath.

  PublisherOA PDFDOI

• Collins-Soper kernel for TMD evolution from lattice QCD

  Physical review. D/Physical review. D. · 2020-07-22 · 115 citations

  articleOpen access1st author

  The Collins-Soper kernel relates transverse momentum-dependent parton distribution functions (TMDPDFs) at different energy scales. For small parton transverse momentum ${q}_{T}\ensuremath{\sim}{\mathrm{\ensuremath{\Lambda}}}_{\mathrm{QCD}}$, this kernel is nonperturbative and can only be determined with controlled uncertainties through experiment or first-principles calculations. This work presents the first exploratory determination of the Collins-Soper kernel using the lattice formulation of q…

  PublisherOA PDFDOI

• Sampling using<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>SU</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>N</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>gauge equivariant flows

  Physical review. D/Physical review. D. · 2021-04-20 · 114 citations

  articleOpen accessSenior author

  We develop a flow-based sampling algorithm for $\mathrm{SU}(N)$ lattice gauge theories that is gauge invariant by construction. Our key contribution is constructing a class of flows on an $\mathrm{SU}(N)$ variable [or on a $\mathrm{U}(N)$ variable by a simple alternative] that respects matrix conjugation symmetry. We apply this technique to sample distributions of single $\mathrm{SU}(N)$ variables and to construct flow-based samplers for SU(2) and SU(3) lattice gauge theory in two dimensions.

  PublisherOA PDFDOI

• Gravitational Form Factors of the Proton from Lattice QCD

  Physical Review Letters · 2024-06-21 · 74 citations

  articleOpen accessSenior author

  The gravitational form factors (GFFs) of a hadron encode fundamental aspects of its structure, including its shape and size as defined from, e.g., its energy density. This Letter presents a determination of the flavor decomposition of the GFFs of the proton from lattice QCD, in the kinematic region 0≤-t≤2 GeV^{2}. The decomposition into up-, down-, strange-quark, and gluon contributions provides first-principles constraints on the role of each constituent in generating key proton structure obser…

  PublisherOA PDFDOI

• Nuclear matrix elements from lattice QCD for electroweak and beyond-Standard-Model processes

  Physics Reports · 2020 · 66 citations

  DOI

Recent grants

• CAREER: Quark and Gluon Structure of Nucleons and Nuclei

  NSF · $257k · 2018–2021

• EAGER: QSA: Accelerating Lattice Quantum Field Theory Calculations Via Interpolator Optimization Using NISQ-Era Quantum Computing

  NSF · $200k · 2020–2022

• CAREER: Quark and Gluon Structure of Nucleons and Nuclei

  NSF · $85k · 2018–2018

Frequent coauthors

• William Detmold

  237 shared

• Michael L. Wagman

  Fermi National Accelerator Laboratory

  184 shared

• Kostas Orginos

  William & Mary

  159 shared

• Zohreh Davoudi

  University of Bonn

  155 shared

• Fernando Romero-López

  Massachusetts Institute of Technology

  154 shared

• Gurtej Kanwar

  152 shared

• Denis Boyda

  133 shared

• Martin J. Savage

  132 shared

Labs

• MIT Center for Theoretical PhysicsPI

Education

• Doctor of Philosophy, CSSM and CoEPP, School of Chemistry and Physics

  University of Adelaide

  2015

• Bachelor of Science (High performance computational physics) (Honours), CSSM and CoEPP, School of Chemistry and Physics

  University of Adelaide

  2011

Awards & honors

• 2023 // Innovator of the Year, South Australian Woman of the…
• 2022 // Ruby Payne-Scott Medal (Australian Institute of Phys…
• 2022 // University of Adelaide James McWha Distinguished Alu…
• 2021 // Wu-Ki Tung Award for Early Career Research on QCD
• 2021 // Maria Goeppert Mayer Award (APS)

Similar researchers at Massachusetts Institute of Technology

• Janet Conradh-205
• Hong Liuh-160
• Isaac Chuangh-90