From Scientific American, March 16, 2023: Big news about a smaller size: MINERvA researchers used a new and entirely independent method to measure a proton’s radius. The team’s measurement of the proton’s radius was 0.73 femtometer, even smaller than the 0.84-femtometer electric charge radius. In either case, it is almost 10,000 times smaller than a hydrogen atom.
MINERvA
From Physics World, March 6, 2023: The MINERvA experiment at Fermilab has been used to study the structure of the proton using neutrinos. Teijin Cai and colleagues working on Fermilab’s MINERvA experiment have showed how information about the proton can be extracted from neutrinos that have been scattered by the detector’s plastic target.
From Science Daily, Feb. 1, 2023: Yesterday, Nature posted new research which used a beam of neutrinos for the first time to investigate the structure of protons. With Fermilab’s MINERvA detector, scientists were able to precisely measure the proton’s size and structure using neutrinos with data gathered from thousands of neutrino-hydrogen scattering events.
For the first time, particle physicists have been able to precisely measure the proton’s size and structure using neutrinos with data gathered from thousands of neutrino-hydrogen scattering events collected by MINERvA, a particle physics experiment at the U.S. Department of Energy’s Fermi National Accelerator Laboratory.
MINERvA is announcing the results of a precision nucleon measurement on Wednesday, Feb. 1. The colloquium will be delivered by Tejin Cai. While a student at the University of Rochester, Cai’s thesis work with advisor Kevin McFarland laid the foundations for the publication in Nature from the MINERvA collaboration. Deborah Harris, MINERvA co-spokesperson, describes the result: “This measurement involves antineutrinos scattering off free protons to produce neutrons. This is a new technique that hasn’t been done before: in the past…
In this lecture, part III of the virtual lecture series, “How to do big science,” Deborah Harris talks about the construction of the MINERvA neutrino experiment at Fermilab. The MINERvA collaboration used a high-intensity neutrino beam to collect data on neutrino interactions with a wide variety of materials. Harris served as the project manager of detector construction, and in 2010, she was elected to be the scientific co-spokesperson of MINERvA.
Hard to believe you can play pool with neutrinos, but certain neutrino events are closer to the game than you think. These special interactions involve a neutrino — famously elusive — striking a particle inside a nucleus like a billiard ball. MINERvA scientists study the dynamics of this subatomic ricochet to learn about the neutrino that triggered the collision. Now they have measured the probability of these quasielastic interactions using Fermilab’s medium-energy neutrino beam. Such measurements are important for current and future neutrino experiments.