Breaking the symmetry between fundamental forces

The CDF and DZero experiments at the Tevatron have published their latest measurement of the electroweak mixing angle. Photo: Reidar Hahn

At present scientists think that at the highest energies and earliest moments in time, all the fundamental forces may have existed as a single unified force. As the universe cooled just one microsecond after the Big Bang, it underwent a “phase transition” that transformed or “broke” the unified electromagnetic and weak forces into the distinct forces observed today.

By Breese Quinn and Willis Sakumoto

news.fnal.gov/2018/07/breaking-the-symmetry-between-fundamental-forces

The secret to measuring the energy of an antineutrino

Scientists at Fermilab use the MINERvA to make measurements of neutrino interactions that can support the work of other neutrino experiments. Photo: Reidar Hahn

Scientists study tiny particles called neutrinos to learn about how our universe evolved. These particles, well-known for being tough to detect, could tell the story of how matter won out over antimatter a fraction of a second after the Big Bang and, consequently, why we’re here at all.

news.fnal.gov/2018/06/the-secret-to-measuring-the-energy-of-an-antineutrino/

MicroBooNE measures charged-particle multiplicity in first neutrino-beam-based result

This plot shows the azimuthal angle difference distribution for events with an observed multiplicity of two for data (points with error bars) and model (histogram). The peaks near positive and negative pi indicate presence of the quasielastic scattering process, while the distribution between the peaks is consistent with predicted contributions from resonance production. The shaded blue area is the estimated cosmic ray background.

MicroBooNE’s first neutrino-beam-based physics result, submitted to the journal Physics Review D this spring, launches the experiment’s journey along this path.

https://news.fnal.gov/2018/05/microboone-measures-charged-particle-multiplicity-in-first-neutrino-beam-based-result/

May 31, 2018 – By Tim Bolton and Aleena Rafique

Neutrino experiment at Fermilab delivers an unprecedented measurement

MiniBooNE scientists demonstrate a new way to probe the nucleus with muon neutrinos.

This interior view of the MiniBooNE detector tank shows the array of photodetectors used to pick up the light particles that are created when a neutrino interacts with a nucleus inside the tank. Photo: Reidar Hahn

Tiny particles known as neutrinos are an excellent tool to study the inner workings of atomic nuclei. Unlike electrons or protons, neutrinos have no electric charge, and they interact with an atom’s core only via the weak nuclear force. This makes them a unique tool for probing the building blocks of matter. But the challenge is that neutrinos are hard to produce and detect, and it is very difficult to determine the energy that a neutrino has when it hits an atom.

By Kurt Reisselmann.

Read this article at the Fermilab web site: http://news.fnal.gov/2018/04/neutrino-experiment-at-fermilab-delivers-an-unprecedented-measurement/