Over the next two to three years the physicists who have spent much of their careers designing and building the Large Hadron Collider (LHC) at CERN expect to start seeing the fruits of their labour. They believe that the machine's enormously energetic –14 TeV – proton-proton collisions may generate the Higgs boson, a previously unobserved particle that is thought to endow all particles with mass. Discovering the Higgs would be the crowning achievement of the Standard Model, the theoretical framework that describes the fundamental particles of matter and their interactions.
Such is the iconic status of the Higgs that it is often portrayed, particularly by the media, as the overriding objective of the LHC. But for many physicists this is not the case. While finding the Higgs would further confirm the immense predictive power of the Standard Model and would certainly justify the SwFr10bn (€6.3bn) being spent on the LHC, it would not represent a new frontier in particle physics. What would really get researchers' pulses racing is the discovery of more exotic, and possibly completely unexpected, new particles. It is these particles that would point to new physics beyond the standard model – physics that might require the existence of the Higgs or might not.
"Not seeing a Higgs particle at the LHC would not be a disaster," says Andrew Cohen, a particle physicist at Boston University in the US. "In fact it might even be more interesting if we didn't see it. Most physicists would guess that the LHC will discover the Higgs, but there are plenty who would be excited if it didn't turn up.
The repercussions of not finding a Higgs, or indeed any new particles in the LHC, are discussed by Edwin Cartlidge in the October issue of Physics World.