Everyone in the physics community is eagerly waiting for this
week's main event on 4 July, when officials at the Large Hadron
Collider are expected to present new results on, and possibly the discovery of, the Higgs boson.
As a sort of warm-up act, scientists working on data from the
Tevatron at Fermilab in Illinois announced their latest data on 2 July,
which gives more strong evidence for the existence of the
The Higgs is the final piece of the Standard Model of physics,
which explains the interactions between all known subatomic
particles and forces, and is required to give all other particles
their mass. The mass of the Higgs boson itself is still unknown,
though the new Tevatron data corroborate
earlier results from both the Tevatron and the LHC that
place the Higgs between 115 and 135 gigaelectron volts (GeV), or
roughly 115 to 135 times heavier than a proton.
This is the final data to come from the Tevatron's search for
the Higgs. For more than a decade, the Tevatron has been watching
elementary particles collide to search for the Higgs. Though
shut down last year, the massive deluge of information could
not be analysed all at once.
Researchers have been sifting through the data to look for any
interesting results. The accelerator smashed together protons and
antiprotons at incredibly high speeds and watched as a variety of
particles were created in their wake. Because they were so heavy,
many of these particles could only exist for fractions of a second
before decaying into lighter particles.
Scientists use the laws of physics to calculate the number of
expected elementary particles from all these decays. What they hope
to see in their data is a tiny excess of subatomic particles coming
from an unknown source -- a potential signal for the Higgs.
Because everything in quantum mechanics runs on probability,
physicists need to be sure that the excess they see is really
exceptionally out of the ordinary and not just some statistical
fluke of nature. That's why they use terms like 3-sigma results,
which indicates that an event has only a 0.13 percent chance of
happening randomly. The ideal situation is a 5-sigma result, which
has only a 0.000028 percent probability of happening by chance.
The new Tevatron data are 2.9-sigma -- a relatively low
significance but, because they support the LHC results, they place
even greater confidence in the signal being a true indication of
the Higgs. Furthermore, the Tevatron sees the Higgs decay in
particular ways that the LHC isn't sensitive to, meaning it could
clarify certain properties of the Higgs that the LHC may struggle