We are not theoretical physicists but an experimentalists. Theorists are contemplating uncharted regions of reality. We are trying to find ways to physically search for these regions, to prove or disprove these theories.
Our work involves studying a fundamental particle of nature, the neutrino. We in the field have been studying this particle since it was first discovered in the 1950’s and we still know very little about it. We use a variety of experiments located at a government research facilities to study them. We’re studying how often neutrinos interact with different types of matter and we’re investigating an anomaly that may indicate the presence of a new type of particle, a sterile neutrino. This is fundamental and something that we don’t know very well. In addition to providing a window to the behavior of neutrinos these measurements will also be used as inputs to future experiments studying other properties of the neutrino.
There are a lot of mysterious measurements in neutrino physics and astrophysics, and these mysteries can be best explained through the introduction of a new particle, the sterile neutrino. The sterile neutrino only interacts with other neutrinos, making it very difficult to detect (or to prove it doesn’t exist).
The University of Florida group joined SBND in August, 2017. SBND is located in the Booster beamline at Fermilab and is one of three Liquid Argon (LAr) detectors comprising the Short Baseline Neutrino (SBN) Program. SBND is the closest of the three detectors.
There is a need to address and resolve the growing evidence for short-baseline neutrino oscillations and the possible existence of sterile neutrinos. Such non-standard particles were first invoked to explain the LSND anti-νμ to anti-νe appearance signal. A follow up experiment, MiniBooNE, observed a significant excess of events that is consistent with the LSND signal. In addition, recent reactor neutrino experiments have observed a deficit of events in the anti- νe interaction rate that can be explained by an ~eV scale sterile neutrino. Reactor experiments have also observed an unexplained excess of events around 5 MeV. Satisfactorily resolving these mysteries involves a dedicated set of experiments placed on the MiniBooNE beam line as well as experiment(s) using a decay-at-rest neutrino source (CCM!).
The CCM light dark matter/neutrino experiment at Los Alamos National Laboratory studies beams of neutrinos (and possible light dark matter!) produced as a by-product by the LANSCE neutron source. UF has been a member of CCM since its early days, in 2019.
There the interaction of high energy protons with a tungsten target produces, in addition to the spallation neutrons, copious pions that decay to provide a beautiful neutrino beam comprising νμ, νe and anti-νμ components. CCM will perform a high-precision measurement of coherent neutrino scattering in LAr and use this interaction channel to search for evidence of light sterile neutrinos. In addition CCM can make unique measurements to exclude regions of light dark matter not able to be probed by any other experiment. CCM is located 15 meters in the backward direction from the proton (neutron) beam, and can be moved to several locations to map out the neutrino oscillation pattern.
Looking beyond SBN, the DUNE/Long-Baseline Neutrino Facility (LBNF) was designed to provide precision measurements of neutrino oscillation parameters. In particular, it will definitively determine the relative mass ordering and measure the amount of CP-violation present in the neutrino sector, solving two of the largest outstanding mysteries in physics associated with neutrino mass.
DUNE consists of two LAr detectors: a detector located near the neutrino source at Fermilab and a far detector located ~1300 km away deep underground in the Sanford Underground Research Laboratory in South Dakota. Fermilab is constructing a new linear accelerator (PIP-II) to produce the high-intensity beam of neutrinos for DUNE. Groundbreaking for PIP-II occurred in March 2019.
The University of Florida group joined MINERνA in November, 2008 and will graduate our last MINERvA student in Fall 2022. MINERνA is an accelerator-based neutrino experiment, located at Fermilab. MINERνA is located in the NuMI beamline, upstream of the MINOS detector.
The global neutrino community is entering an era of precision neutrino measurements. This requires that we have a precise knowledge of cross section interaction rates, final state interactions, and nuclear effects. Prior to MINERvA, neutrino cross sections were poorly known with 20 to 100 percent total error. There are also several unresolved discrepancies in various measurements, for example, the high axial mass extracted from K2K and MiniBooNE CCQE sample, and an unusual coherent pion production from K2K and SciBooNE. MINERνA is a neutrino scattering experiment with a broad physics program. MINERνA produced measurements in the 1-10 GeV range. No other experiment existed during MINERvA’s running to perform precision measurements in MINERνA’s energy range! MINERνA produced several cross section measurements, studied strange particle production, nuclear effects, and parton distribution functions.
The University of Florida group joined MiniBooNE in March, 2014. MiniBoONE was an accelerator-based neutrino experiment, located at Fermilab. MiniBooNE was located in the Booster beamline, the same beamline currently being used by SBND.
MiniBooNE was designed to resolve the unusual measurements seen by LSND that indicated the presence of a new particle, the sterile neutrino. MiniBooNEs results, which are continuing to this day (Spring 22) have further added to the mystery of what is going on in the neutrino sector.