Redefining our knowledge of the nature of the universe is job one at Fermilab.

Much of what we know about the physical laws that govern the universe we owe to the past four decades of discoveries at Fermilab, the U.S. Department of Energy’s (DOE) Fermi National Accelerator Laboratory, located near Chicago, Illinois. Established in 1967, the facility quickly assumed prominence in the field of high-energy particle physics. The discovery of both the bottom quark (1977) and its counterpart, the top quark (1995), were made here. Today, Fermilab is best known for science at the Tevatron, the world’s highest-energy particle collider.

Some 1,900 Fermilab employees, including about 900 physicists, engineers and computer professionals, and another 2,300 scientists and students from across the country and around the world conduct research at Fermilab’s Tevatron Collider. Much of their work centers on the DZero and Collider Detector at Fermilab (CDF) experiments.

To chronicle their progress, the lab’s daily e-mail newsletter, Fermilab Today, publishes each Thursday a new “Result of the Week” from the collider detectors. That weekly report, which has been published since September 18, 2003, links the record-breaking performance of the Tevatron particle accelerator to the extraordinary results of the DZero and CDF experiments. Among the topics covered are leptoquarks, pomerons, tau leptons, top quarks, single top quarks, mesons by the dozens, matter-matter asymmetry, W bosons, Z bosons, charm quarks, strange quarks, bottom quarks, electrons, the strong force, the weak force and multiple searches (including those for supersymmetry), dark matter, extra dimensions and the Higgs boson. Taken together, these precision results redefine our knowledge of nature.

“The Fermilab collider program is running at full speed,” said Dennis Kovar, associate director of the DOE’s Office of Science for High-Energy Physics. “In the past year alone, the two experiments have produced 77 Ph.D.s and 100 publications that advance the state of our knowledge across the span of particle physics at the energy frontier.”

The DZero experiment is an international collaboration of about 600 physicists from 90 institutions in 18 countries. DZero scientists conduct research on the fundamental nature of matter as revealed by the high-energy interactions of protons and antiprotons—an intense search for subatomic clues that reveal the character of the building blocks of the universe.

One discovery announced in September, 2008, is a new particle comprising three quarks, the Omega-sub-b (Ωb). The discovery of this doubly strange particle brings scientists a step closer to understanding exactly how quarks form matter and to completing the “periodic table of baryons.” Baryons are particles that contain three quarks, the basic building blocks of matter. “The observation of the doubly strange b baryon is yet another triumph of the quark model,” said Dmitri Denisov, DZero cospokesperson at Fermilab. “Our measurement of its mass, production and decay properties will help to better understand the strong force that binds quarks together.”

The CDF experimental collaboration, which involves 700 physicists from 61 institutions and 13 countries, is also committed to studying particle collisions at the world’s highest-energy particle accelerator. Their goal is to discover the identity and properties of the particles that make up the universe and to understand the forces and interactions among those particles.

In August, both collaborations reported that for the first time ever, they were able to exclude, with 95 percent probability, a mass for the long-sought Higgs boson of 170 GeV. Their results came from combining Tevatron data from the two experiments to advance the quest for the Higgs boson. This result not only restricts the possible masses where the Higgs boson might lie, but also demonstrates that the Tevatron experiments are sensitive to potential Higgs boson signals.

In April, 2007, the scientists presented results from rare particle processes never observed before and new constraints on the mass of the Higgs boson, which in principle make the observation of this elusive particle at the Fermilab Tevatron collider more likely. And earlier that year, CDF collaboration scientists announced results of the world’s most precise measurement made up until then by a single experiment of the mass of the W boson, the carrier of the weak nuclear force and a key parameter of the Standard Model of particles and forces. Prior to this, ALEPH, an experiment at CERN (the European Center for Nuclear Research), held the record for the most precise W mass measurement.

Having gained a much better understanding of their detector and the processes it records, CDF scientists are optimistic that they can soon further improve the precision of their W-mass result. “You have to sweat every detail of the analysis,” said Fermilab physicist and cospokesperson Robert Roser. “Our scientists cannot take anything for granted in an environment in which composite particles such as protons and antiprotons collide. We need to understand the many different subatomic processes and take into account the capabilities of our detector for identifying the various particles.”