Scientists are widely expected to present evidence on Tuesday that the most coveted prize in particle physics - the Higgs boson - has been glimpsed.
While the Higgs is crucial to our understanding of the Universe, it has never been observed by experiments.
At a seminar here in Geneva, teams will present a progress report in their hunt for the tiny particle at the Large Hadron Collider (LHC).
But the LHC has not recorded enough data to claim a formal discovery.
Finding the Higgs was a key goal for the $10bn (£6bn) particle smasher. The collider hosts two experiments - Atlas and CMS - that are searching for the particle independently.
There is intense excitement among physicists working at Cern, the Geneva-based organisation which operates the collider, over hints that the hunters have cornered their quarry.
"It is a fantastic time at the moment, you can feel people are enthusiastic," Dr Christoph Rembser, a senior scientist on the Atlas experiment, told BBC News. "It is really very lively."
If the Universe really is like that, I find it really quite breathtaking and humbling that we can understand it"
Prof Stefan Soldner-Rembold, from the University of Manchester, called the quality of the LHC's results "exceptional", adding: "Within one year we will probably know whether the Higgs particle exists, but it is likely not going to be a Christmas present."
He told me: "The Higgs particle would, of course, be a great discovery, but it would be an even greater discovery if it didn't exist where theory predicts it to be."
The Higgs boson is a "fundamental" particle; one of the basic building blocks of the Universe. It is also the last missing piece in the leading theory of particle physics - known as the Standard Model - which describes how particles and forces interact.
The Higgs explains why other particles have mass. As the Universe cooled after the Big Bang, an invisible force known as the Higgs field formed together with its associated boson particle.
It is this field (and not the boson) that imparts mass to the fundamental particles that make up atoms. Without it, these particles would zip through the cosmos at the speed of light.
The way the Higgs field works has been likened to the way photographers and reporters congregate around a celebrity. The cluster of people are strongly attracted to the celebrity and create resistance to his or her movement across a room. In other words, they give the celebrity "mass".
Asked where a Higgs discovery would rank among scientific milestones of the last 100 years, Dr Shears said: "I don't think that I could compare it to any other scientific advance... it is quite different.
"This is a prediction that stems from a very mathematical approach to understanding the Universe, which is guided by the idea that it is simple at heart.
"If the Universe really is like that, I find it really quite breathtaking and humbling that we can understand it."
