W Bosons light up the Standard Model
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
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.
A copy of the paper can be found at this link
Citation is: Phys. Rev. D 71, 091108(R) (2005)