Higgs Boson & Field
The year 2012 will go down in history as a landmark year, when physicists discovered a fundamental particle that may answer one of the greatest riddles of all.
Investigators believe their discovery to be the long-coveted Higgs Boson, an invisible particle that explains the mystery of mass.
Without the Higgs, say theorists, we and all the other joined-up atoms in the Universe would not exist.
Theorised back in 1964, the boson carries the name of a Briton, Peter Higgs. He was the first to suggest that a field of these particles could explain a nagging anomaly: Why do some particles have mass and why do others, such as light, have none?
That question was a gaping hole in the Standard Model, the conceptual framework for understanding the nuts-and-bolts particles and forces that constitute the cosmos.
CERN's announcement on July 4 stressed the need to confirm that the newcomer is the Higgs, a margin of uncertainty that probably prevented the discovery from gaining a Nobel this year.
And further work is needed to see exactly how the Higgs—or Higgses, if the boson exists in different flavours—interacts with other particles.
Investigators believe their discovery to be the long-coveted Higgs Boson, an invisible particle that explains the mystery of mass.
Without the Higgs, say theorists, we and all the other joined-up atoms in the Universe would not exist.
Theorised back in 1964, the boson carries the name of a Briton, Peter Higgs. He was the first to suggest that a field of these particles could explain a nagging anomaly: Why do some particles have mass and why do others, such as light, have none?
That question was a gaping hole in the Standard Model, the conceptual framework for understanding the nuts-and-bolts particles and forces that constitute the cosmos.
CERN's announcement on July 4 stressed the need to confirm that the newcomer is the Higgs, a margin of uncertainty that probably prevented the discovery from gaining a Nobel this year.
And further work is needed to see exactly how the Higgs—or Higgses, if the boson exists in different flavours—interacts with other particles.
The Higgs Boson Explained from PHD Comics on Vimeo.
Further Reading
The Standard Model
Just like periodic table of elements in Chemistry exists so does physics have its own table to organize particle zoo out there. This table, or better said arrangement, is called standard model. This particles are divided into two major sections; fermions and bosons. As always, there are these specific properties one has to obey to be part of one group. Indeed, fermion is any particle any particle which obeys the Fermi–Dirac statistics (and follows the Pauli exclusion principle). Fermions contrast with bosons which obey Bose-Einstein statistics. In shorter and more basic wording, we can say fermions are particles with half-integer spin where no two identical fermion particles may occupy the same quantum state simultaneously (for example no two electrons in a single atom can have the same four quantum numbers). Bosons, on the other hand, are integer spin particles and not subject to the Pauli exclusion principle (any number of identical bosons can occupy the same quantum state - like photons for example). We see there are two characteristics here to determine whether particle is boson or fermion.
A fermion can be an elementary particle (for example electron) or it can be a composite particle (for example proton). Fermions have properties, such as charge and mass, which can be seen in everyday life. They also have other properties, such as spin (always positive), weak charge, hypercharge, and colour charge, whose effects do not usually appear in everyday life. These properties are given numbers called quantum numbers. There are 12 different types of fermions. Each type is called a "flavor." Their names are:
A fermion can be an elementary particle (for example electron) or it can be a composite particle (for example proton). Fermions have properties, such as charge and mass, which can be seen in everyday life. They also have other properties, such as spin (always positive), weak charge, hypercharge, and colour charge, whose effects do not usually appear in everyday life. These properties are given numbers called quantum numbers. There are 12 different types of fermions. Each type is called a "flavor." Their names are:
- Quarks — up, down, strange, charm, bottom, top (2 up quarks and 1 down quark make a proton, and 2 down quarks and 1 up quark make a neutron)
- Leptons — electron, muon, tau, electron neutrino, muon neutrino, tau neutrino
Gauge bosons
Gauge bosons are what make the fundamental forces of nature possible (we are not yet sure if gravity works through a gauge boson). Every force that acts on fermions happens because gauge bosons are moving between the fermions, carrying the force. Bosons follow a theory called Bose-Einstein statistics. The Standard Model says that there are 12 gauge bosons:
- 8 kinds of gluons
- photon
- W+, W-, and Z
There are four basic known forces of nature. These forces affect fermions, and are carried by bosons traveling between those fermions. The Standard Model explains three of these four forces.
All these particles have all been seen either in nature or in the laboratory. The Standard Model also predicts that there is a Higgs boson. The Standard Model says that fermions have mass (they are not just pure energy) because Higgs bosons travel back and forth between them. The Higgs boson is the only elementary particle in the Standard Model that physicists have not yet found.
- Strong force; this force holds quarks together to make hadrons such as protons and neutrons. The strong force is carried by gluons. The theory of quarks, the strong force, and gluons is called quantum chromodynamics (QCD). The residual strong force holds protons and neutrons together to make the nucleus of every atom. This force is carried by mesons, which are made up of two quarks.
- Weak force; this force can change the flavor of a fermion and causes beta decay. The weak force is carried by three gauge bosons: W+, W-, and the Z boson.
- Electromagnetic force; this force explains electricity, magnetism, and other electromagnetic waves including light. This force is carried by the photon. The combined theory of the electron, photon, and electromagnetism is called quantum electrodynamics.
- Gravity; this is the only fundamental force that is not explained by the Standard Model. It may be carried by a particle called the graviton. Physicists are looking for the graviton, but they have not found it yet.
All these particles have all been seen either in nature or in the laboratory. The Standard Model also predicts that there is a Higgs boson. The Standard Model says that fermions have mass (they are not just pure energy) because Higgs bosons travel back and forth between them. The Higgs boson is the only elementary particle in the Standard Model that physicists have not yet found.