… there must be a Higgs field that pervades all space; the Higgs particle would be the carrier of the field and would interact with other particles. The Higgs is a crucial part of the standard model of particle physics—but no one’s ever found it …
… In the ’60s Peter W. Higgs, Robert Brout and François Englert proposed a solution.
Elaborating on his proposal, today’s version suggests that in the very early Universe all particles were massless. Shortly after the birth of the Universe in the Big Bang, as the universe expanded the temperature fell below a critical value where a new type of field developed everywhere in the Universe. We call this particular field the Higgs field. Some particles coupled to this field and the property they acquired is what we measure as mass. That is, particles are not solid in themselves but can be seen as a wave on a water surface. Although a wave moves no water from one side of a lake to another, it carries a lot of information: energy, momentum, amplitude, wavelength.
For particles, mass is just another property acquired by interacting with the ever pervading Higgs field and that property we perceive as mass. Thus as the field developed below the critical temperature some particles acquired mass and some others not. The fact that the mass is “given” to the particles through an external mechanism solved the problems in the theory.
You may find it strange that this field suddenly appeared in the Universe but there are several similar physics phenomena around us. A ferromagnet heated to a temperature higher than the “Curie temperature” will lose its magnetization. However, as it is cooled, it will again develop a magnetic field with a specific direction. We call this type of phenomena “spontaneous symmetry breaking".
As you might know, we have never seen a Higgs boson! You can imagine that confirming the Higgs mechanism is one of the hottest topics in physics. The technical problem is that we can’t exactly predict the mass of the Higgs boson itself. This means that we are obliged to scan off bit by bit the possible range for the Higgs boson. Today we have excluded that the Higgs boson is lighter than the total mass of 120 protons! With the new accelerator that we are building at CERN, the Large Hadron Collider, we should be able to cover the entire possible range and that’s really exciting! If on the other hand we really exclude the Higgs mechanism completely, then there must be something entirely unexpected out there! …
2008-03-16 | achtphasen | 23:06:13 | 
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2008-04-09 | 23:25 
