The
Higgs boson or
Higgs particle is a proposed
elementary particle in the
Standard Model of particle physics. The Higgs boson's
existence would have profound importance in
particle physics because it would prove the existence of
the hypothetical
Higgs field—the simplest
[4]
of several proposed explanations for the origin of
the symmetry-breaking mechanism by which elementary
particles acquire
mass.
[Note
2] The leading explanation is that a
field exists that has non-zero strength everywhere—even
in otherwise empty space—and that particles acquire mass by interacting
with this so-called Higgs field. If this theory is true, a matching
particle—the
smallest possible excitation of the Higgs
field—should also exist and be detectable, providing a crucial test of
the theory. Consequently, it has been the target of a long search in
particle physics. One of the primary goals of the
Large Hadron Collider (LHC) at
CERN in
Geneva, Switzerland—the most powerful
particle accelerator and one of the
most complicated scientific instruments
ever built—is to test the existence of the Higgs boson and measure its
properties which would allow physicists to confirm this cornerstone of
modern theory.
The Higgs boson is named for
Peter
Higgs who, along with two other teams, proposed the mechanism that
suggested such a particle in
1964[6][7][8]
and was the only one to explicitly predict the massive particle and
identify some of its theoretical properties.
[9]
In mainstream media it is often referred to as "the God particle",
after the title of
Leon Lederman's
book on the topic (1993). Although the proposed particle
is both important and elusive, the epithet is strongly disliked by
physicists, who regard it as inappropriate
sensationalism since the particle has nothing
to do with God nor any mystical associations,
[10][11]
and because the term is misleading: the crucial focus of study is to
learn how the symmetry breaking mechanism takes place in nature - the
search for the boson is part of, and a key step towards, this goal.
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. It has no
spin,
electric charge, or
colour charge. It is also very unstable,
decaying into other particles almost immediately. Some
extensions of the Standard Model predict the existence of more than one
kind of Higgs boson.
Proof of the Higgs field (by confirming its boson), and evidence of
its properties, are seen as likely to greatly affect human understanding
of the universe, validate the final unconfirmed part of the Standard
Model as essentially correct, indicate which of several current particle
physics theories are more likely correct, and open up
"new" physics beyond
current theories.
[12]
If the Higgs boson were shown not to exist, other
alternative sources for the Higgs mechanism would need to be
considered. On 4 July 2012, the
CMS and the
ATLAS experimental teams at the LHC independently
announced that they each confirmed the formal discovery of a previously
unknown boson of mass between 125–
127 GeV/c2, whose
behaviour so far has been "consistent with" a Higgs boson, while adding a
cautious note that further data and analysis were needed before
positively identifying the new particle as being a Higgs boson of some
type.
