Discovery of Higgs particle preserves Standard Model

The hoopla surrounding the verification of the Higgs particle has died down, so it’s a good time to recap what the fuss was all about.

I’ll use an example from electromagnetism as a visualization model. Surrounding any electric charge such as a proton is a field that can interact with any other electric charge, either attracting or repulsing depending on whether the charges are alike or opposite.

Moving the charge will cause a change in the field. In classical physics we say a distortion in the form of an electromagnetic wave transmits information about the new position of the charge.

In quantum physics, instead of visualizing the distortion of the field as a wave, we say that energy of moving the charge transmits a photon. The wave-particle duality allows us to visualize light as either a wave or a particle.

For every field when excited there is a corresponding particle analogous to the photon, which we say is the manifestation of the electromagnetic field.

The Higgs particle, far from being the "God" particle, is the manifestation of the Higgs field that was postulated four decades ago.

In the 1970s theoretical physicists realized that there was a close connection between two of the four forces of nature: the electromagnetic and the weak forces (the other two are the strong force and gravity).

The two forces can be described by the same mathematical theory, which implies that electricity, magnetism, light and beta decay (a type of radiation) are manifestations of a single force called "electroweak." This unification of these forces formed the basis for the Standard Model, but there was a problem with the math.

All of the particles "popped out" of the math having no mass. The photon has zero mass, but the W and Z bosons that carry the weak force have masses more than 100 times that of the proton.

Robert Brout, Francois Englert and Peter Higgs saved the Standard Model when they proposed the existence of an invisible field that pervades the universe and gives mass to the W and Z bosons when they interact with it, now called the "Higgs field."

At first there seemed to be no way to experimentally verify the existence of this invisible Higgs field, although otherwise the Standard Model has proved to be exceptionally accurate.

The Nobel Prize awarded to Higgs last year was not so much for proposing the existence of the field, but rather for the intuitive leap that there should be a particle that manifests when the Higgs field is excited, as the photon does with the electromagnetic field.

The problem was that the mass of the proposed Higgs particle would have to be even greater than that of the W and Z, which were just at the top of the range that could be produced in the most powerful atom smasher. The discovery of the Higgs would have to wait until a bigger particle collider could be built.

The Large Hadron Collider filled the bill, and using it, CERN announced the discovery of the Higgs on July 4, 2012, thus completing the Standard Model — for now anyway.

Richard Brill is a professor of science at Honolulu Community College. His column runs on the first and third Fridays of the month. Email questions and comments to brill@hawaii.edu.