FILE - In this Thursday, March 22, 2007 file photo two engineers works to assemble one of the layers of the world's largest superconducting solenoid magnet (CMS, Compact Muon Solenoid) at the European Organization for Nuclear Research (CERN)'s Large Hadron Collider (LHC) particule accelerator, in Geneva, Switzerland. (AP Photo/KEYSTONE/Martial Trezzini, File)

GENEVA (AP) — Scientists say the world's biggest atom smasher plans to announce Wednesday enough evidence has been gathered to show that the long-sought "God particle" answering fundamental questions about the universe does indeed exist.

But after decades of work and billions of dollars spent, researchers at the European Organization for Nuclear Research, or CERN, say they aren't quite ready to set off celebratory fireworks with an official discovery announcement.

Instead, experts familiar with the research at CERN's vast complex on the Swiss-French border say Monday its massive data will essentially show the footprint and shadow of the key particle known as the Higgs boson, rather than provide proof it has been glimpsed or discovered.

CERN theorist John Ellis says "we've discovered something which is consistent with being a Higgs."