The
Higgs boson or
Higgs particle is a proposed
elementary particle in the
Standard
Model of
particle physics. The Higgs boson is named after
Peter Higgs who, along with others, proposed
the mechanism that
predicted such a particle in 1964. The existence of the Higgs
boson and the associated
Higgs field explain why the other massive elementary particles
in the standard model have their
mass. In this theory, the Higgs field has a non-zero
field everywhere, even in its
lowest energy state. Other massive elementary particles
obtain mass through the continuous interaction with this field (however, not all
elementary particles have mass). The Higgs field interaction is the simplest mechanism
which explains why some elementary particles have mass. The Higgs boson—the
smallest
possible excitation of the Higgs field—has been the target of a long search in particle
physics. One of the primary design goals of the
Large Hadron Collider at
CERN
in
Geneva,
Switzerland—one of the most complicated scientific instruments
ever built— was to test the existence of the Higgs boson and measure its
properties.
Because of its role in a fundamental property of elementary particles, the Higgs boson has
been referred to as the "God particle" in popular culture, although virtually all scientists regard
this as a hyperbole. According to the Standard Model, the Higgs particle is a
boson, a type of
particle that allows multiple identical particles to exist in the same place in the same quantum
state. Furthermore, the model posits that the particle has no
intrinsic spin, no
electric charge,
and no
colour charge. It is also very unstable, decaying almost immediately after its creation.
On 4 July 2012, the
CMS and the
ATLAS experimental collaborations at the
Large Hadron Collider
announced that they observed a new boson that is consistent with the Higgs boson,
noting that further data and analysis were needed before the particle could be positively identified.
The existence of the Higgs boson was predicted in 1964 to explain the Higgs
Because the Higgs boson is a very massive particle and decays almost immediately when
created, only a very high-energy
particle accelerator can observe and record it. Experiments
to confirm and determine the nature of the Higgs boson using the
Large Hadron Collider (LHC)
at
CERN began in early 2010, and were performed at
Fermilab's
Tevatron until its close in late
2011. Mathematical consistency of the Standard Model requires that any mechanism capable
of generating the masses of elementary particles become visible at energies above
1.4 TeV;
[6]
therefore, the LHC (designed to collide two 7 TeV proton beams, but currently running at
4 TeV each) was built to answer the question of whether or not the Higgs boson exists.
[7]
On 4 July 2012, the two main experiments at the LHC (
ATLAS and
CMS) both reported
independently the confirmed existence of a previously unknown particle with a mass of about
125 GeV/c2 (about 133 proton masses, on the order of 10
−25 kg), which is "consistent with the
Higgs boson" and widely believed to be the Higgs boson. They cautioned that further work would
be needed to confirm that it is indeed the Higgs boson (meaning that it has the theoretically
predicted properties of the Higgs boson and is not some other previously unknown particle) and,
if so, to determine which version of the Standard Model it best supports