Rice University logo


W Bosons light up the Standard Model

Above, left to right: Adam Lyon (Fermilab), Greg Pawloski (Rice University) and Rice University graduate student Andrew Askew (now a Postdoc at Florida State), who worked on this analysis as part of his Ph.D., are looking at this interaction.

Particle physics is the science that attempts to understand the basic building blocks of matter and the interactions that govern their behavior. Numerous experiments, and years of research, have led to a very successful theory called the Standard Model. In the Standard Model matter is made of quarks that interact by exchanging particles called bosons.

The interaction of one of these bosons, the W, with another, the photon, is being studied with the DZero experiment. By doing so, particle physicists are testing the structure of the theory that describes their interactions. The Standard Model describes exactly how the W boson and photon interact. If something unexpected is observed, then the Standard Model is incorrect, and a new theory must be found.

The Tevatron collider at Fermilab smashes beams of protons and antiprotons together. In these collisions, the quarks (from the protons) annihilate antiquarks (from the antiprotons) to produce new particles, which can then be studied. Sometimes the quark and antiquark annihilate to produce a W boson which then radiates a photon, providing a means by which physicists can study the actual W-photon interaction. In this study the scientists examined the spectrum of energies of the photons produced in this way, and compared this to the predictions of the Standard Model.

The data are in excellent agreement with the Standard Model. The Tevatron continues to produce record amounts of data and the DZero team plans to continue studying this process in ever greater precision. It is only by testing our theories to ever higher degrees of precision that we can hope to further our understanding of nature.


An event display of a W boson - photon event taken with the DZero detector.

A copy of the paper can be found at this link

Citation is: Phys. Rev. D 71, 091108(R) (2005)