Postdoc Felipe Ortega-Gama
As an undergraduate at Tecnológico de Monterrey in Mexico, Felipe Ortega-Gama took part in the Science Undergraduate Laboratory Internships program at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility. There, he worked with Raúl Briceño, a scientist at the lab’s Center for Theoretical and Computational Physics and a professor at Old Dominion University. Under Briceño’s guidance, Ortega-Gama was introduced to quantum chromodynamics (QCD), the theory governing the strong interaction that binds quarks and gluons to form hadrons.
Inspired by the precision of QCD predictions, Ortega-Gama pursued a Ph.D. at William & Mary, where he collaborated with Briceño and Jozef Dudek, a senior scientist at Jefferson Lab. His research led to a groundbreaking lattice QCD calculation, published in Physical Review D, that revealed a fundamental link between two pion interactions: the spacelike process, where an electron scatters off a pion, and the timelike process, where an electron and antielectron annihilate to form two pions. This study provided numerical evidence supporting the connection between these reactions.
An early-career physicist mathematically connects timelike and spacelike form factors, opening the door to further insights into the inner workings of the strong force. A new lattice QCD calculation connects two seemingly disparate reactions involving the pion, the lightest particle governed by the strong interaction. One reaction is known as the spacelike process, where an electron is bounced off a pion. The second reaction, known as the timelike process, is when an electron and antielectron collide, annihilate each other, and produce two pions. The lattice QCD numerical calculation is simultaneously able to describe the spacelike and timelike processes, demonstrating the interconnectedness of different reactions described by QCD. While this connection had been observed experimentally, now physicists have the math to corroborate it.
One of the key challenges in lattice QCD calculations is translating finite-volume numerical results into real-world infinite-volume predictions. To address this, Ortega-Gama extended a formalism developed by Briceño and Dudek, allowing for precise theoretical extrapolation. He utilized computational tools developed by the Hadron Spectrum (HadSpec) collaboration, working closely with Jefferson Lab scientist Robert Edwards to streamline calculations.
Throughout his Ph.D., Ortega-Gama refined these techniques with weekly discussions with Dudek, ensuring the accuracy and robustness of his computations. His expertise in both theoretical formalism and numerical calculations places him among the top researchers in lattice QCD.
In September 2024, Ortega-Gama joined the University of California, Berkeley, as a postdoctoral scholar, continuing his work on QCD calculations with Briceño, now a professor at UC Berkeley. His contributions are advancing the understanding of hadron interactions and shaping the future of theoretical physics.