MIT Physicist Probes Neutrinos to Unlock Universe's Fundamental Mysteries

Faith Reyes was not always certain she wanted to be a physicist. In high school, she studied mathematics and science as separate subjects, disconnected from any larger purpose or application. Then her physics teacher, Ms. Bolster, changed that. Bolster showed her how abstract concepts connected to the real world, how curiosity could be channeled into actual investigation. Reyes started a physics club where students gathered before school to run experiments. "I just sort of fell in love with physics then," she recalls. That enthusiasm never left her.

Now a sixth-year PhD student at MIT's Laboratory for Nuclear Science, Reyes works in the Formaggio Group studying neutrinos—elementary particles so small and so reluctant to interact with ordinary matter that they pass through the human body constantly, undetected, streaming from the sun. Detecting them at all requires ingenuity. Reyes is part of an international collaboration called Ricochet, which operates at a nuclear reactor in Grenoble, France, and focuses on observing coherent elastic neutrino-nucleus scattering, a low-energy interaction where a neutrino bounces off an atomic nucleus. The work matters because the Standard Model, the framework physicists use to describe fundamental particles and forces, is accurate but incomplete. Neutrinos, with their strange properties and minimal mass, offer a window into what lies beyond it.

Reyes' path through graduate school did not follow the trajectory she initially imagined. When she joined Ricochet, she expected to work on a project at MIT. A few years in, it became clear that project would not be ready in time. She pivoted to the work happening in France, traveling there for a three-month stint to learn the technical details of the experiment's detectors. That first visit was largely routine—she performed the repetitive work necessary to understand how the detectors functioned. But as Ricochet expanded from two detectors to nine and eventually eighteen, the volume of manual work became unsustainable. Reyes and a colleague recognized an opportunity: many of those repetitive tasks could be automated.

Together, they built a software framework that could handle much of the low-level analysis and detector monitoring that Reyes had once done by hand. The project became transformative for her development as a physicist. By working closely with the detectors and building tools to manage them, she gained a granular understanding of how the entire experiment operated. More than that, she moved from being someone who followed instructions to someone whose collaborators trusted her judgment and relied on her expertise. "It felt like my collaborators trusted me, and I had something of value to give to the collaboration," she says. The experience was both validating and humbling.

That shift in responsibility changed how Reyes approached research itself. Earlier in her academic career, she was more comfortable being directed than proposing her own ideas. Leading projects and coordinating groups pushed her to trust her own judgment. "I think I was sometimes not really standing up for myself," she reflects. "But now I feel more confident in my position and my prowess as a physicist." That confidence, she has come to understand, is one of the most important things her PhD has taught her.

Reyes has spent significant time in France—three months initially, then another three months, and most recently nine months through the Chateaubriand Fellowship. Working in the same office as her collaborators made coordination across time zones easier and deepened her connection to the experiment. She also developed an affection for French culture and its approach to work-life balance. She has even considered living there permanently. Outside the lab, she plays video games and crochets, a hobby she took up during her time in France. She often crochets while watching television, appreciating the chance to work with her hands while her mind wanders.

As Reyes moves toward the next phase of her career—she is considering a postdoctoral position—she carries with her the lessons of her graduate experience. Her research may help reveal what physics looks like beyond the Standard Model. But perhaps equally important, her time at MIT and with the Ricochet collaboration has shown her that scientific breakthroughs depend not just on individual brilliance but on mentorship, collaboration, adaptability, and the willingness to lead. "I've learned a lot of lessons," she says. "Especially about wrangling people."