FIRST the good news: the Large Hadron Collider has found hints of the much-ballyhooed Higgs particle. Now the bad: the hints are tentative and may vanish with further data. Also, the collider has glimpsed no sign of supersymmetry, the leading theory to explain dark matter.
In the wreckage of colliding protons, the ATLAS detector at the LHC, located at CERN near Geneva, Switzerland, has found an unexpected abundance of pairs of particles called W bosons with energies between about 120 and 140 gigaelectronvolts (GeV).
That could be due to the decay of a Higgs particle with a mass in that range. If it is, it would be a coup 鈥� the Higgs is the last undiscovered particle in physics鈥檚 standard model and is thought to give all particles mass.
Advertisement
Kyle Cranmer of New York University reported the excess last week at the Europhysics Conference in Grenoble, France. The ATLAS team also saw smaller excesses in pairs of photons and Z bosons, which could be due to Higgs decays too. But each effect is seen in only a small number of collisions, and their statistical significance is a far cry from that required to declare a 鈥渄iscovery鈥�.
The LHC鈥檚 other main detector, CMS, has also found an excess in a similar range, the conference heard, but that result rests on similarly shaky statistical ground.
More data will settle the matter. 鈥淲e will have answered the Higgs鈥檚 Shakespeare question 鈥� to be or not to be 鈥� by the end of next year,鈥� predicts Rolf-Dieter Heuer, CERN鈥檚 director general.
鈥淲e will have answered the Higgs鈥檚 Shakespeare question 鈥� to be or not to be 鈥� by the end of next year鈥�
Meanwhile, the LHC has found no signs of supersymmetry, a theory intended to take physics beyond the standard model 鈥� which cannot explain dark matter, among other things. Heuer says the theory is still in the running, as the LHC has taken only 0.1 per cent of the data it will eventually collect. 鈥淲e just have to be patient,鈥� he says.
