The secret to measuring an antineutrino’s energy

Miranda Elkins (left) worked on this with Rik Gran (right) while she was a master’s student at the University of Minnesota-Duluth. She is now a Ph.D. student at Iowa State University.

It is no secret that neutrinos change flavor or oscillate as they travel from one place to another, and that the amount they change depends on how much time they have to change. This time is directly related to the distance the neutrino traveled and the energy of the neutrino itself. Measuring the distance is easy. The hard part is measuring the neutrino energy.

Read the entire article at the Fermilab web site:

Which way did it go? A view from the top

This table summarizes the forward-backward asymmetry measurements in top quark-antiquark events at the Tevatron.

Over the last decade, measurements by the CDF and DZero collaborations of how top quarks flee the scene of the crime, the so-called “forward-backward asymmetry,” caused quite a stir as they clashed with then state-of-the-art theoretical predictions for the Tevatron. The disagreement tantalized physicists with visions of new, unexpected particles influencing the behavior of the top quark. Now, with the final, combined word from the experiments, Fermilab has placed a capstone on its study of the forward-backward asymmetry, and the measurements and theory now agree.

By Ziqing Hong and Jon Wilson

The article can be found here:

Photons continue to enlighten physicists

The cross section is presented as a function of the transverse energy of the photon.

You may be familiar with particles of light, called photons. Physicists give the name “prompt photons” to those that are produced by two particles smashing together — hard collisions — as contrasted with those resulting from the decay of other particles. The Tevatron produced prompt photons by the hard collisions between protons and antiprotons.

By: Andy Beretvas and Alessandra Lucà

The article is here:

What’s the deal with antimatter?

Antimatter can be found in science fiction and in fact. It both powers fictional starships and is associated with one of the most perplexing mysteries in modern physics. Since our theories suggest that matter and antimatter should have been made in equal quantities, yet we observe only matter, this mystery is really quite fundamental: Why are we here at all?, by Don Lincoln