image: UT Arlington Assistant Professor Raquel Castillo Fernández
Credit: Photo courtesy UT Arlington
Scientists from The University of Texas at Arlington are part of the Short-Baseline Near Detector (SBND) project at Fermi National Accelerator Laboratory in Illinois that has identified the detector’s neutrino interactions for the first time. The discovery was made after nearly a decade of planning, prototyping, and constructing the detector by an international collaboration of scientists.
The Neutrino Group at UTA, under the leadership of physics Professors Andrew Brandt and Jaehoon Yu, Associate Professor Jonathan Assadi, and Assistant Professor Raquel Castillo Fernández, is playing a critical role in advancing research within the SBND experiment. Also contributing to UTA’s efforts on the project are postdoctoral researcher Leo Aliaga Soplín, graduate students Shweta Yadav and Manuel Dall’Olio, and former UTA postdoctoral student Gabriela Vitti Stenico.
“This is an exciting milestone. We have worked for years to get to this point and now we can focus on moving the project forward as we search for new physics,” Dr. Castillo Fernández said. “The existence of sterile neutrinos has captivated the scientific community for decades, and with this incredible detector, we are on the verge of breakthroughs that could redefine our understanding of the universe. The excitement and potential ahead are truly inspiring.”
SBND is the final element that completes Fermilab’s Short-Baseline Neutrino (SBN) Program and will play a critical role in solving a decades-old mystery in particle physics. Getting SBND to this point has been an international effort. The detector was built by an international collaboration of 250 physicists and engineers from Brazil, Spain, Switzerland, the United Kingdom, and the United States.
Neutrinos are the second most abundant particle in the universe. Despite being so abundant, they’re incredibly difficult to study because they only interact through gravity and the weak nuclear force, meaning they hardly ever show up in a detector.
Neutrinos come in three types—muon, electron, and tau. Perhaps the strangest thing about these particles is that they can change from type to type, switching from muon to electron to tau. Scientists have a good idea of how many of each type of neutrino should be present at different distances from a neutrino source. Yet observations from a few previous neutrino experiments disagreed with those predictions, leading some researchers to believe there may be more than three types.
The SBN Program at Fermilab will perform searches for neutrino oscillation and look for evidence that could point to a fourth neutrino. SBND is the near detector for the SBN Program, while ICARUS, which started collecting data in 2021, is the far detector. A third detector called MicroBooNE finished recording particle collisions with the same neutrino beamline that same year.
SBND expects to see as many as 7,000 interactions per day, more neutrinos than any other detector of its kind. The large data sample will allow researchers to study neutrino interactions with unprecedented precision.
The SBND international collaboration is hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory. The collaboration consists of 38 partner institutions, including national labs and universities from five countries. SBND is one of two particle detectors in the SBN Program that provides information on a beam of neutrinos created by Fermilab's particle accelerators.