Higgs signal sinks from view

Nature : Last month’s “excess events” at the Large Hadron Collider (LHC) were probably just statistical fluctuation, rather than hints of the Higgs boson, according to new data. The events appeared as an excess of W bosons at around 144 gigaelectronvolts (GeV) in the ATLAS and Compact Muon Solenoid detectors; higher-than-expected numbers of W bosons were predicted to be an early indicator of the Higgs. Presented today at the Lepton Photon 2011 conference in Mumbai, India, the new results, which use about twice the data, show the significance of the find dropping from 2.8 sigma to 2 sigma, which means that the odds of it being the real Higgs have fallen, from more than 99% to 95%—the opposite of what one would hope with additional data. While teams at the LHC can’t yet say where the Higgs is, the CMS experiment ruled out its presence at energies between 145 and 400 GeV, while the ATLAS has eliminated large patches between 146 and 466 GeV. If the Higgs exists, it may be at the lower mass end of the energy spectrum, between about 120 and 140 GeV.