Mike Cooke

The number of jets that appear in an event at DZero can reveal important information about the strong force. Take a look at any given proton-antiproton collision recorded at DZero and you’re likely to spot a jet, but not the kind you’d find at an air show. When a quark or a gluon is produced in a high-energy collision, it will turn into a spray of particles, called a jet, due to interactions with the strong force. This is the…

Observing something may begin a story, but the subsequent study fills in the rest of the book. The observation of a new particle or a new decay mode is not the end of a story, but the beginning of one. New chapters must follow as the properties of the phenomenon are studied and their measurements refined. Earlier this year, the LHCb collaboration opened the book on a new decay mode for the neutral Bs meson, a pairing of a bottom…

CDF and DZero team up to tackle the measurement of the mass of the top quark. When two big players team up to tackle a challenge, they can make a big impact in the hard-hitting world of particle physics. Collisions at the Tevatron created massive opponents for teams of physicists, including the heaviest observed particle in the Standard Model, the top quark. Pinning down the mass of the top quark plays a pivotal part in probing the Standard Model, which…

Do photons and W and Z bosons interact with each other by the specific rules dictated by the Standard Model, or does their behavior indicate something unexpected? The Standard Model dictates very specific rules that govern the way the photon (γ) and W and Z bosons interact with each other. In the Standard Model, the neutral photon and Z boson do not directly interact, but the charged W bosons can interact with each other or with the photon or the…

Measurements of W-plus-jets production will provide an important reference for hadron collider experiments for many years to come. Certain measurements are bound to leave their marks on the field of high-energy physics for many years and become permanent reference points for future efforts. A recent set of results from DZero has focused on measurements that will be a cornerstone of the Tevatron’s legacy, the precise study of W boson production in association with jets. Studying any form of jet production…

The combined CDF and DZero search for the Higgs boson decaying to a pair of bottom quarks revealed evidence for a particle consistent with the Standard Model prediction. The month of July 2012 is bound to be remembered as the crescendo of the summer of the Higgs boson. It began with the announcement of results from the Tevatron’s search for the Standard Model Higgs boson, followed immediately by reports of the observation of a new particle by the LHC experiments….

New measurements from DZero add pieces to the puzzle of matter-antimatter asymmetry. One of the most puzzling properties of matter in our universe is that there’s so much of it in the first place. When new matter is created during a particle collision, an equal amount of antimatter accompanies it nearly every time. The Standard Model allows only a very slight deviation from this symmetry, and not nearly enough difference between matter and antimatter to explain the abundance of matter…

The Forward Proton Detector measured protons and antiprotons that scattered at extremely small angles with respect to the beam. Not every interaction between a proton and antiproton at the Tevatron was a head-on collision. Some collisions would break apart one or both of the particles, perhaps creating rare forms of matter like top quarks or possibly Higgs bosons. However, elastic collisions did often occur. In these, both the proton and antiproton are left intact and no additional particles are created….

The running of the strong coupling constant describes the way that the strong force loses strength at short distances. The strong force changes its strength at different distance scales, a phenomenon known as the running of the strong force coupling constant. More like pulling on a rubber band than pulling apart two magnets, its strength diminishes at short distances between quarks but increases rapidly when trying to pull two quarks apart. At some point it takes less energy to produce…

Every search channel counts when looking for the Higgs boson in the remaining allowed mass region. The Higgs boson, the elusive final fundamental particle predicted by the Standard Model, is running out of hiding places. Until the search is over and the Higgs boson is either observed or excluded, efforts remain focused on improving the sensitivity of our search in the remaining allowed mass range. Currently, two or more experiments exclude Higgs boson masses below 115 GeV and above 129…