Physics grad from top 5 US university, will answer any college level physics/engineering/math/chemistry question that I can.
There's gotta be a few of you who are not done with exams yet!
If you can tell me if the Higgs Boson exists I'll pay you
And no, I'm can't tell you whether or not it exists.
The Higgs boson is the only particle that is part of the "standard model" of particle physics that has never been observed experimentally. This is because its interactions with particles we can observe easily are extremely rare and difficult to measure. One of the goals of the LHC is to confirm its existence experimentally, but many physicists believe it will not achieve its goal (as is alluded to in deepceleron's chart)
The chart shows sigma/sigmaSM, which (I think) is essentially a ratio of the likelihood of that particle existing with the mass (in eV, a unit of mass or energy) on the x-axis. The LHC and Tevatron experiments have excluded the possibility of the Higgs existing with certain ranges of mass, but there is still a window where it could exist. At higher masses, (which are out of the range the LHC can observe), the Higgs could still exist, even if the window area turns out to be excluded as well. Deepceleron, please correct me if I'm wrong about this.