No sooner has one mammoth accelerator delivered its first big result, than discussions begin on what should replace it.
At the annual get-together of Nobel prizewinners in Lindau, Germany, this week, all the talk was of whether the Large Hadron Collider is the right instrument to find out what exactly the LHC has found.
The problem is that the LHC collides two beams of protons. Protons are made of a melange of smaller particles, quarks and the gluons that hold them together, so when two of them hit, the result is a confusing array of shrapnel.
Finding something that looks like the Higgs boson has required painstaking reconstructions of what was fleetingly produced in the violence of the collisions. So much different stuff is produced that it might simply be too confusing an environment in which to pin down with any certainly what the putative Higgs's true properties are, and so reach a conclusive identification.
"The question is, will the LHC be able to do it at all? Or do we need something else?" says Carlo Rubbia, an experimentalist who as the head of CERN, Europe's particle physics lab near Geneva, Switzerland, played a major part in getting the LHC project off the ground in the 1990s.
Particle physicists' traditional answer to this problem has been to suggest building a machine to collide electrons and their antiparticles, positrons. Unlike protons, electrons are elementary particles, so don't disintegrate on impact, making it clearer what is produced when they collide.
To read more, click here.