Dr. Daniel Pitonyak, assistant professor of physics, presented a pair of invited talks based on research supported by his recent National Science Foundation (NSF) grant to study the 3-dimensional structure of hadrons. Dr. Pitonyak presented “Updated QCD Global Analysis of SSAs: New Experimental Data and Constraints” as part of the QCD Evolution Workshop, which was held at the University of Virginia. He followed that presentation with a virtual invited talk—”Updated QCD Global Analysis of SSAs: H~, the Soffer Bound, and Lattice gT”—at the 6th International Workshop on Transverse Polarization Phenomena, which was hosted by Almo Collegio Borromeo in Pavia, Italy.

Dr. Daniel Pitonyak, assistant professor of physics, co-authored a paper in the Journal of High-Energy Physics, “New tool for kinematic regime estimation in semi-inclusive deep-inelastic scattering,” with colleagues from Jefferson Lab, University of Torino, and Penn State Berks. They developed a phenomenological tool to guide the interpretation and analysis of high-energy electron-proton collisions, including an interactive notebook based on Machine Learning techniques. This research was supported by Dr. Pitonyak’s recent National Science Foundation (NSF) grant.

Physics majors Michel Malda ’22 and Ben Gordon ’22 attended the APS April Meeting: Quarks to Cosmos in New York City this past weekend with Dr. Daniel Pitonyak, assistant professor of physics. There, Michel gave a talk titled “Updated QCD Global Analysis of Single Transverse-Spin Asymmetries with Additional Constraints from Experimental Data and Lattice QCD,” Ben presented “Analysis of the cos2φ and cosφ Modulations in Semi-Inclusive Deep-Inelastic Scatterring,” and Dr. Pitonyak discussed “Comprehensive Study of SSAs within the Jefferson Lab Angular Momentum (JAM) Global Analysis Framework.” The research was supported by Dr. Pitonyak’s National Science Foundation (NSF) grant to study the 3-dimensional structure of hadrons. 

Dr. Daniel Pitonyak, assistant professor of physics, co-authored “First Global QCD Analysis of the TMD g1T from Semi-Inclusive DIS Data,” which was published by the peer-reviewed journal Physical Review D. This work provides insight into how longitudinally polarized quarks move inside a transversely polarized proton. It is the second piece Dr. Pitonyak has had published by Physical Review D in less than a year, and both research projects were supported by his grant from the National Science Foundation.

Dr. Daniel Pitonyak, assistant professor of physics, gave a remote invited talk at the Institute for Nuclear Theory Workshop on Fragmentation Functions on Nov. 2, 2021. Dr. Pitonyak presented “Multi-Parton Fragmentation Functions in a QCD Global Analysis of Single-Spin Asymmetries.”

Dr. Daniel Pitonyak, assistant professor of physics, recently gave three invited or contributed talks, and two physics majors—Michel Malda ’22 and Ben Gordon ’22—gave talks at major conferences. On Oct. 13, Malda presented “Updated QCD Global Analysis of Single Transverse-Spin Asymmetries” and Gordon spoke about “Analysis of the cos(2φ) Modulation in Semi-Inclusive Deep-Inelastic Scattering” at the American Physical Society Division of Nuclear Physics Fall Meeting, where Dr. Pitonyak gave a contributed talk, “Update on the Jefferson Lab Angular Momentum Collaboration’s Global Analysis of SSAs.”  

Dr. Pitonyak also gave an invited talk, “Status of Phenomenology for the Transversity Distribution,” at the 5th Workshop on the QCD Structure of the Nucleon on Oct. 4, followed by “Small-x Helicity Evolution and the Proton Spin Puzzle” at the 24th International Spin Symposium on Oct. 22.

Dr. Daniel Pitonyak, assistant professor of physics, gave a contributed talk, “Global Analysis of SSAs from Current and Future Data,” at the 22nd Particles and Nuclei International Conference on Sept. 5. Dr. Pitonyak participated virtually in the tri-annual conference featuring plenary speakers from throughout the U.S. and world.  

Dr. Daniel Pitonyak, assistant professor of physics, gave a contributed talk, “Impact Study of Future Data on the Tensor Charge from a QCD Global Analysis,” at the 19th International Conference on Hadron Spectroscopy and Structure on July 28. Dr. Pitonyak also gave an invited talk, “Proton Spin at Small x,” at the Electron-Ion Collider Users Group Summer Meeting on August 6. Both presentations were virtual.

Dr. Daniel Pitonyak, assistant professor of physics, co-authored “First analysis of world polarized DIS data with small-x helicity evolution” for the August issue of Physical Review D. The results will help in understanding how the spin of quarks and gluons contribute to the overall spin of the proton. Dr. Pitonyak’s co-authors are from The Ohio State University, New Mexico State University, and the Thomas Jefferson National Accelerator Facility. The authors are members of the Jefferson Lab Angular Momentum Collaboration.

Dr. Daniel Pitonyak, assistant professor of physics, presented remotely for the QCD Evolution Workshop, hosted by the University of California at Los Angeles. His invited talk was titled, “Phenomenological Study of the Origin of SSAs and Extraction of the Tensor Charge.” Dr. Pitonyak discussed his team’s results on the first global fit of single-spin asymmetry data from SIDIS, Drell-Yan, e+e− annihilation into hadron pairs, and proton-proton collisions, which will help provide insight on the 3-dimensional structure of hadrons.