An image released by Cern today of a collision detected by the CMS experiment, showing characteristics expected from the decay of a Higgs boson. Photograph: Thomas McCauley and Lucas Taylor/Cern 12.50pm: Cern, the European particle physics lab near Geneva, has called a special seminar at 1pm GMT at which scientists working on the two main detectors on the Large Hadron Collider (LHC) will share their results. They will hold a press conference at 3.30pm when they are expected to announce they have good evidence for the existence of the Higgs boson. Follow events here as they unfold during the afternoon, including the announcement, the key data and reaction from around the world. 12.56pm: In case you've been distracted by other news over the past few months, here's a quick catch-up. The Higgs boson is a subatomic particle that was predicted to exist nearly 50 years ago. Scientists have been searching for the particle for decades, but so far have no solid proof that it is real. Although the Higgs boson grabs headlines -- unsurprising, given its nickname, the God particle -- it is important only because its discovery would prove there is an invisible energy field that fills the vacuum throughout the observable universe. Without the field, or something like it, we would not be here. Scientists have no hope of seeing the field itself, so they search instead for its signature particle, the Higgs boson, which is essentially a ripple in the Higgs field. According to theory, the Higgs