Don Lincoln

Don Lincoln is a Fermilab scientist.

The production of two Z bosons in a single collision is among the rarest phenomena expected to occur at the Tevatron. It is about 20,000 times rarer than finding a single W boson. Exploiting the entire Run II DZero data set netted just 10 events of this kind. The weak nuclear force is the weakest interaction that physicists at the Tevatron have successfully studied. Like all subatomic forces, we can understand it as being caused by the exchange of force…

In the telephone game a message is garbled by changes in how it is repeated. Today’s article describes how we defeat a similar subatomic process using the world’s largest collection of top quarks. When I was young, a bunch of us would play the telephone game. In this game, a person would whisper a message to someone. That person would whisper it to someone else and, after a series of whispers, we’d compare what was the last person heard to…

Particle collisions that look like this are used to search for leptoquarks. This figure is specifically for (electron + up/down quark) type collisions. Leptoquarks are theoretical particles. While there are theories that suggest these particles are real, we live in a world full of leptons (the electron is the most familiar example) and quarks (which are generally found in the nucleus of an atom.) We don’t understand why there are two types of particles (quarks and leptons) and we have…

Sand fairies redux

The top figure shows the normal production and decay processes of top quarks. In the bottom figure, the magenta section shows a FCNC process. This type of event is forbidden in the Standard Model and, if it were observed, would require rewriting of the books. In an earlier article, I compared the search for something that the Standard Model deems impossible to searching for tiny fairies in the sand on a beach. I also promised that this wouldn’t be the…

The search for the Higgs boson is like a jigsaw puzzle. Just as no single piece reveals the whole picture, no single analysis will find the Higgs boson. Without all pieces, the picture is incomplete. In the 1960s, a bevy of physicists pieced together our current understanding of the electromagnetic and weak forces. The first task was to show how those forces were two facets of an underlying single force, called the electroweak force. The second task they accomplished showed…

One theoretical speculation about why gravity is so much weaker than the other known forces postulates the existence of additional dimensions beyond the familiar three. If this idea is true, then the LHC might be able to create microscopic black holes. If observed, they would have a major impact on our understanding of the laws of physics. According to the laws of physics as we currently understand them, it is impossible to make microscopic black holes at the LHC. There…

The W’ boson is a hypothetical, much more massive, cousin of the W boson. This article describes a new search for it. In the late 1960s, theorists were able to mathematically show that the electromagnetic and weak nuclear forces were actually two facets of a single common force, now called the electroweak force. This new theory postulated two new particles called the W and Z bosons. The theory was vindicated in 1983 with the discovery of both of them by…