Sunday, July 8, 2012

An Extraordinary Triumph for Science

    On July 4, two teams of researchers from CERN, Europe's center for particle physics research, made an extraordinary announcement, reporting the discovery of a new particle that appeared to match the profile of the long-sought Higgs boson.  One team, using the CMS detector, announced the discovery of a particle with a mass of 125 GeV (giga-electron volts), and the other, using the ATLAS detector, reported a mass of 126 GeV.  In tandem, they had found impressive evidence for a major find.

    The Higgs boson is the relic of the field that filled all of space during the nascent moments of time.  In those fleeting instants, as the Higgs field transformed, it lent mass to most of the other elementary particles and caused them to differentiate in their properties.  This process, called the Higgs mechanism, is a key ingredient of the Standard Model of particle physics, explaining why there are significant differences among particles.  For example photons, the particles that carry the electromagnetic force, are massless and act over a long range, while W and Z particles, carriers of the weak interaction, are heavy and act over a short range.

    One might use the analogy of water freezing into ice to think of how the Higgs mechanism works.  Imagine that the Higgs field in the hot early universe was a sea of liquid water.  Other particles moved through the sea like speed boats, each travelling at the speed of light and interacting with each other in the same way.  However, as the universe cooled, the Higgs "sea" began to freeze into tracks of slush.  Moving through these slush tracks in various directions, most of the particles were forced to slow down, becoming heavier.  The amount of mass, or heaviness acquired, depended on the angle that the particle was moving.  This led to profound differences in the properties of those particles.

    Additional work needs to be done to establish that the newly found particle truly is the Higgs boson.  However, the announcement was met with much optimism that the long road to finding the Higgs has almost reached its end.

    For more about the Large Hadron Collider and the Higgs boson, see my book Collider: A Search for the World's Smallest Particles