Of course, Higgs is also the name of the person, Peter Higgs, who first developed the underlying theory (along with five others who will be in contention for the Nobel Prize if and when the Higgs particle is discovered.)

Q. How will we know it when we find it?

A. In the simplest implementation of the Higgs mechanism, we know precisely what the properties of the Higgs boson should be. That’s because of its connection to the Higgs mechanism, which tells us that its interactions with any particular particle are determined by that particular particle’s mass.

Knowing the interactions, we can calculate how often the Higgs boson should be produced and the ways in which it should decay. It can decay only into those particles that are light enough for energy to be conserved. Roughly speaking, the Higgs boson decays into the heaviest such particles the most often, since it interacts with them the most strongly.

What we don’t know, however, is the Higgs boson’s mass. The Higgs boson decays differently, depending on its mass, since a heavier Higgs boson can decay in ways that a light Higgs boson can’t. So when experimenters look for the Higgs boson, they look over a range of masses and employ a variety of search strategies.

Q. What do we know about it so far?

A. Experimenters have already ruled out a large range of masses. The Higgs boson, if it exists, has to be heavier than 114.4 giga-electron volts (GeV), which are the units of mass that particle physicists use. By comparison, protons, the bedrock of ordinary matter, are about 1 giga-electron volt, and an electron is only half a million electron volts.

Based on recent searches by the L.H.C., the Higgs boson is also excluded between about 140 GeV and 500 GeV. This makes the most likely region for the Higgs mass to be between about 115 and 140 GeV, which is the range Tuesday’s results should focus on, although in principle heavier Higgs boson masses are in contention too.

I don’t want to shatter hopes, but don’t count on Tuesday’s results being definitive. This is the toughest range of masses for the L.H.C., and detection is tricky for this range. I suspect they will have enough evidence not to exclude the Higgs, but too little to fully pin it down without next year’s data.