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.
Scientists of the Fermilab experiment MicroBooNE have published the results of a search for a type of hidden neutrino — much heavier than Standard Model neutrinos — that could be produced by Fermilab’s accelerators. These heavy neutrinos are expected to have longer travel times to the MicroBooNE detector than the ordinary neutrinos. This search is the first of its kind performed in a liquid-argon time projection chamber, a type of particle detector. MicroBooNE scientists have used their data to publish constraints on the existence of such heavy neutrinos.
Scientists on Fermilab’s MicroBooNE experiment have measured neutrino interactions on argon with unprecedented statistics and precision using data on the resultant muons — in particular, the muon’s momentum and angle. The experiment features the first liquid-argon time projection chamber with the resolution and statistics to carry out such a measurement. Researchers will use the result to improve simulations of neutrino interactions. These improvements are important for neutrino experiments in general, including the Short-Baseline Neutrino program experiments and the international Deep Underground Neutrino Experiment, both hosted by Fermilab.
Fermilab scientist Alexey Burov has discovered that accelerator scientists misinterpreted a certain collection of phenomena found in intense proton beams for decades. Researchers had misidentified these beam instabilities, assigning them to particular class when, in fact, they belong to a new type of class: convective instabilities. In a paper published this year, Burov explains the problem and proposes a more effective suppression of the unwanted beam disorder.
Fermilab’s NOvA neutrino experiment records in its giant particle detector the passage of slippery particles called neutrinos and their antimatter counterparts, antineutrinos. Famously elusive, these particles’ interactions are challenging to capture, requiring the steady accumulation of interaction data to be able to pin down their characteristics. With five years’ worth of data, NOvA is adding to scientists’ understanding of neutrinos’ mass and oscillation behavior.
For the first time, a team at Fermilab has cooled and operated a superconducting radio-frequency cavity — a crucial component of superconducting particle accelerators — using cryogenic refrigerators, breaking the tradition of cooling cavities by immersing them in a bath of liquid helium. The demonstration is a major breakthrough in the effort to develop lean, compact accelerators for medicine, the environment and industry.