Don Lincoln

Don Lincoln is a Fermilab scientist.

Weinberg’s angle

The original physics idea behind today’s measurement came when a physicist was driving a car like this one. So much for the claim that physicists aren’t cool… One bright day in 1967, future Nobelist Steven Weinberg was driving to work in his brand new, bright red Camaro convertible when he had an epiphany. He understood the mechanism that broke the symmetry between the weak nuclear force, which is responsible for some forms of radioactivity, and the electromagnetic force, which holds…

Lepton fizz

While one can safely open a can of soda, if you add energy to it by shaking it, it will fizz all over. If the familiar electron and muon turn out to be made of smaller objects, we can add energy to them, which might be emitted as photons. Grab a can of soda, shake it thoroughly, and open it up. What do you get? It’s an explosion of fizz. Today’s column is about a similar thing in the subatomic…

Casting a wide net

To search for unanticipated physics, you need to make sure you do searches that make the minimum number of assumptions of what new physical phenomena might look like. I give a lot of public lectures. I speak about DZero’s attempts to find the Higgs boson or the search for supersymmetry. Most of the time, the talks go off without a hitch. But every so often, a hand will go up, and I’ll get hit by a thoughtful question. The words…

Bump hunters

Scientists look for evidence that two particles coalesce into a new kind of particle. Scientists expect that this particle would be observed by an unexpected bump in the expected signal (shown here in yellow). A proton consists of smaller particles called partons. Parton is a generic term for the quarks and gluons that make up the proton. In the LHC, two protons collide. What this really means is that a parton from one proton is made to collide with a…

This plot depicts measurements from three different experiments as well as the Standard Model prediction. All three measurements agree with one another pretty well and none differ very much with the prediction. Inside a neutral B meson, the bottom antiquark can emit a W boson and convert to a charm antiquark. The W boson decays into a charm quark and strange antiquark, resulting in the J/ψ and Φ final state. Since the mid 1950s, scientists have known that there are…

The DZero Result of the Week describes rather complex measurements. The accessible language can sometimes mask the true difficulties scientists face in searching for answers. Making a physics measurement is hard—even for an analysis that doesn’t confirm a theory. Scientists are searching for evidence that would support two popular theories—supersymmetry and Higgs bosons. Today’s article mixes the two. Like all measurements, this is a challenging endeavor. The first step is to figure out ways to select the right collisions to…

A recent article set a limit on the mass of the W’, a hypothetical cousin of the W boson. While that measurement is still valid, the CMS result described here sets a bigger limit still. (Clifford is a registered trademark of Norman Bridwell.) There are a lot of things we don’t understand about the subatomic realm, which is why we spend so much time studying it. Mysteries are fascinating, but maddening. My personal favorite conundrum stems from the knowledge that…

Today’s measurement shows top quarks have a discernible preference for the direction in which they are created. The top quark, discovered at Fermilab in 1995, is the heaviest elementary particle known to date. By colliding protons and antiprotons to annihilate quarks and antiquarks in the beams, physicists can produce a top-antitop quark pair. Collisions similar to these produce light particles that are carefully studied, and their characteristics agree with the Standard Model. Does the Standard Model also accurately describe in…

Physicists are on a mission to find the Higgs boson, the missing piece of the standard model. Variations on the headline, “Fermilab scientists search for the God particle” are common in today’s media. “God particle,” an inaccurate pseudonym for the Higgs boson taken from Leon Lederman’s eponymous book, is certainly attention-grabbing. However, readers should raise an eyebrow at the use of such a simple word as “search,” which totally understates the magnitude of the effort involved in looking for the…

The history of particle physics is replete with silly names and this subject is no different. One of the original names for a model which predicted doubly charged Higgs bosons was the Mini Moose Model. Perhaps the most pressing topic in modern particle physics is the exploration of the energy realm called the TeV, or teraelectronvolt. One TeV is equal to a trillion electron volts and is the energy scale of the Tevatron (and the source of the accelerator’s name)….