Meet the Particle Family
Author: 一毫秒的永恒
Physics is full of particles such as neutrons and photons, but it also contains particles stranger than most people imagine. They have different properties and sizes, and many bear evocative names, from supersymmetric particles to the “God particle.” Today, let us meet some of the coolest members of this almost indescribable family.
Higgs Boson
The Higgs boson is enormously important to physics. Often nicknamed the “God particle,” it is associated with the origin of mass for many elementary particles. In 1964, physicists were trying to understand why some particles were more massive than others and where that mass came from. Peter Higgs proposed what became known as the Higgs mechanism. The Higgs boson is associated with the Higgs field, which the mechanism assumes permeates the universe. Together, the field and its boson are thought to account for the masses of many fundamental particles. Scientists hoped the mechanism would solve this puzzle and complete the Standard Model, our existing description of known particles. In 2012, experiments at CERN’s Large Hadron Collider (LHC) confirmed the discovery of a particle whose properties were consistent with those of the Higgs boson, providing crucial support for the Standard Model. The LHC continues to collect data so that researchers can investigate the Higgs field and Higgs boson in greater detail.
Neutrino
Neutrinos are subatomic particles with extremely little mass that interact only rarely with ordinary matter. They usually travel at close to the speed of light. Trillions pass through your body at any given moment, yet so few interact with normal matter that they produce almost no detectable effect. Neutrinos are created by the Sun, cosmic rays, and radioactive decay inside Earth. They also have antiparticles called antineutrinos; under certain conditions, neutrinos and antineutrinos can annihilate one another.
Sparticle
“Sparticle” is short for “supersymmetric particle,” a term from supersymmetry. The theory proposes that every known particle has an undiscovered partner: every fermion should have a bosonic partner, and every boson a fermionic one. The electron’s supersymmetric partner, for example, is the selectron; the quark’s partner is the squark.
As of 2026, no sparticle has been found experimentally. Why do we not observe these particles in the universe? Scientists think they may be far more massive than ordinary particles, and massive unstable particles generally decay very quickly. In essence, a sparticle would disappear almost as soon as it was created. Producing one requires extraordinarily high energies of the kind present shortly after the Big Bang, although a large particle accelerator such as the LHC might be able to recreate them. As for why sparticles should be so heavy, physicists have suggested that some hidden sector of the universe, beyond our ability to detect directly, may cause supersymmetry to break. We could neither see nor touch such a sector, sensing it only through its interactions.
Graviton
The graviton is a hypothetical particle in theories of quantum gravity and a possible carrier of the gravitational interaction. In quantum field theory, fundamental interactions can often be described through the exchange of particles. Electromagnetism, for example, is mediated by photons, massless particles that carry the electromagnetic force. By analogy, scientists have proposed that gravity may be mediated by particles called gravitons.
As of 2026, no graviton has been detected experimentally, and its existence remains theoretical. Because gravitons would interact so weakly with matter, detecting a single one directly is thought to be almost impossible under real physical conditions. One study, for example, calculated that even a detector as massive as Jupiter, operating at 100% efficiency in a close orbit around a neutron star, would detect only about one graviton every ten years under the most favorable conditions.
Antimatter
Antimatter is matter composed of antiparticles, the counterparts of particles in ordinary matter. When matter and antimatter meet, they annihilate one another, releasing enormous energy in accordance with E=mc². The process has an exceptionally high energy density. Scientists believe that every ordinary particle has a corresponding antiparticle with the same mass but opposite charge. The positron, for example, is the electron’s antiparticle: it carries the same magnitude of electric charge but the opposite sign.
Quark
Quarks are elementary particles proposed by Murray Gell-Mann and George Zweig. They participate in the strong interaction and are the basic constituents of hadrons such as protons and neutrons. Gell-Mann took the word “quark” from a line in James Joyce’s Finnegans Wake: “Three quarks for Muster Mark.” Quarks always occur in combinations because the force binding them grows as the distance between them increases. Pulling them apart would require so much energy that free quarks do not occur in nature. Six types, or “flavors,” of quark are known: up (u), down (d), strange (s), charm ©, bottom (b), and top (t). A proton, for example, contains two up quarks and one down quark, while a neutron contains two down quarks and one up quark. Up and down quarks are the least massive. Heavier quarks rapidly turn into up or down quarks through particle decay. Because those heavier quarks are generally unstable, strange, charm, top, and bottom quarks can be produced only in high-energy particle collisions, such as those involving cosmic rays or particle accelerators, and decay soon afterward.
That concludes our tour of these remarkable particles. Which one is your favorite? Does the sheer variety of the universe feel a little more astonishing now? If you want answers to every question, keep searching for them yourself.
References
- https://www.livescience.com/13593-exotic-particles-sparticles-antimatter-god-particle.html
- Wikipedia: “Higgs boson,” “Quark,” “Superpartner,” “Neutrino,” “Antimatter,” and “Graviton”
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