The runup to Christmas looks exciting for the Large Hadron Collider at Cern near Geneva. Staff at the laboratory have arranged a special seminar on Tuesday 13 December at which the latest results in the search for the Higgs boson will be made public. The presentation is due to happen directly after the lab's scientific policy committee has convened one of its regular meetings behind closed doors.

So what can we expect to hear? The two main groups that hunt the Higgs boson, the Atlas and CMS detector collaborations, will describe their results separately, unlike the recent combined figures put out this month in Paris. There has been too little time to merge the most up-to-date results from both experiments.

If both teams have analysed all their data, up to the last proton-proton collision recorded in October this year, we are into interesting territory. John Ellis, a theoretical physicist at King's College London, who in 1976 wrote the first paper on how to find the Higgs boson, says that if the particle exists in the simple form invoked by the Standard Model (the set of equations that describe how known particles interact) it should start to show up in their data, but probably not strongly enough for them to claim a discovery. If the elusive boson is a mirage, the scientists should be able to rule it out completely. All of this is contingent on their having analysed every last bit of their data, though, and that is unlikely.

It might turn out that one experiment sees a hint of a signal and the other sees nothing. In that case, the existence of the Higgs boson looks doubtful. But if both see hints, the key issue will be whether the signals match up, that is do they point to a Higgs particle with the same mass. If they do, then the odds on the Higgs being real start to look a lot better.

Physicists are often quoted as saying that finding no Higgs boson would be more exciting than finding one. Steven Weinberg, who shared the Nobel prize for physics in 1979, once told me that finding the Standard Model Higgs boson would not rescue physics but send it into the doldrums. I quoted him in Massive, saying: "It would be just what we're expecting and it would give us no clue to anything new. Finding several kinds of Higgs, or even no Higgs at all, would be better."

There are popular theories that demand the existence of a bunch of Higgs bosons. Some versions of supersymmetry (Susy), an idea that says every kind of particle has an invisible twin, call for five Higgs bosons, all with different masses. A Susy Higgs boson might look very similar to a Standard Model Higgs at the LHC, because it decays into the same variety of lighter particles. But the Susy version might give a weaker signal, and so take more time to find.

If the LHC scientists say definitively that there is no Higgs boson, it would be bad news for supersymmetry. As Ellis puts it: "If they don't find a Standard Model Higgs I would begin to worry seriously about supersymmetry because in popular models a Susy Higgs should appear in a similar way to a Standard Model Higgs."

Beyond supersymmetry, there are alternative theories that replace the Higgs with other ways to give mass to fundamental particles. The Higgs boson is simply the quantum, or signature particle, of the postulated Higgs field, and it is the field that really matters.

According to Peter Higgs and the five other physicists who came up with the theory in 1964, the Higgs field is what separated the electromagnetic force from the weak force (which goes to work in certain nuclear reactions, including those that make the sun shine) when the universe was young. It did this by making the particles that carry the weak force (the W and Z bosons) heavy, while leaving particles of light (the quanta of the electromagnetic field) massless. It isn't a huge leap to envisage the field giving mass to other basic particles, like electrons and quarks.

The alternatives to the Higgs theory are exciting because whatever form they take, they break new ground in physics. Some call for a new force of nature, others for extra dimensions, but these are only two of the options. I hope to write about them in more detail next week.

But for now we have to wait. The seminar in December is going to be a milestone in the search for the Higgs boson, whatever the message from the scientists. You can be sure the news will leak out on a blog before the seminar arrives, and that plenty of speculative nonsense will be written too. As one Cern physicist put it: "This should be fun."