Theories that go beyond the Standard Model and attempt to explain the nature of dark matter, neutrino masses, and other phenomena that cannot be accounted for in the current theory.
Standard Model of Particle Physics: The basic framework of particle physics, which includes the elementary particles, their properties, and their interactions.
Quantum Field Theory: The theoretical framework that describes the behavior of subatomic particles and their interactions using quantum mechanics and special relativity.
Symmetries in Physics: A mathematical concept that represents a physical property that remains invariant under transformations. Symmetries play a central role in the Standard Model and Beyond the Standard Model physics.
Gauge Theory: A type of quantum field theory that describes the interactions between subatomic particles mediated by force-carrying particles, such as photons and gluons.
Supersymmetry: A proposed symmetry between particles with different spin values, which predicts the existence of a partner particle for each known particle.
Grand Unification: The idea that all the fundamental forces of nature, including electromagnetism, the weak force, and the strong force, can be described by a single unified force at very high energies.
Dark Matter: A hypothetical form of matter that does not interact with light or normal matter, but its existence can be inferred from gravitational effects.
Neutrino Physics: The study of the properties and behavior of neutrinos, which are neutral particles that interact only weakly with other matter.
Cosmological Constant Problem: The discrepancy between the observed value of the cosmological constant, an energy density associated with empty space, and the theoretical predictions based on the Standard Model.
Baryogenesis: The theoretical study of how the universe evolved from an initial state with an excess of matter over antimatter.
Extra Dimensions: The idea that there may be additional dimensions beyond the familiar four dimensions of space and time, which would have important implications for Beyond the Standard Model physics.
Collider Physics: The experimental study of subatomic particles by colliding them together at high energies, to investigate their properties and interactions.
Dark Energy: A hypothetical form of energy that is thought to be responsible for the accelerating expansion of the universe.
Axions: Hypothetical particles that may solve some problems in the Standard Model, including the strong CP problem and dark matter.
Technicolor: A theoretical extension of the electroweak theory, which proposes a new, strongly interacting force that would generate masses for the elementary particles.
Supersymmetry: This theory proposes that for every Standard Model particle there is a supersymmetric partner particle that is much heavier. It predicts the existence of new particles such as supersymmetric electrons, quarks (squarks) and gauge bosons (gauginos).
String theory: It suggests that the fundamental particles of nature are not point-like but are tiny vibrational strings that reside in higher-dimensional space-time. This theory proposes extra dimensions beyond the three of space and one of time commonly known.
Grand Unified Theory (GUT): This unified theory of all three of the gauge interactions (weak, strong, and electromagnetic). The main prediction of GUT models is that the proton decays, and it determines the lifetime and branching ratios of this rare process.
Extra-dimensions and Kaluza-Klein theory: It proposes that there are more spatial dimensions than just the usual three we experience. Kaluza-Klein theory suggests that these extra dimensions are hidden in plain sight, and the fundamental particles of the Standard Model are actually higher-dimensional objects.
Technicolor: It proposes that there are new strong interactions that trigger the creation of new particles, such as a techni-higgs instead of a Higgs boson.
Majorana neutrinos and neutrino oscillations: It proposes that neutrinos are their anti-particles, and it tries to explain the phenomenon of neutrino oscillations, where neutrinos change "flavor" as they travel.
Dark matter: It is a hypothetical type of matter that does not interact with light, electromagnetism, or the strong or weak gauge interactions, but that interacts with the gravitational force. Dark matter plays an important role in cosmology, and its existence may be required to explain observed gravitational lensing, and possibly the existence of galaxies.
Axions: This type of particle would be very light, very weakly interacting, and would solve a long-standing puzzle in the Standard Model involving the strong interaction.
Leptoquarks: These particles would carry both baryon (strong) and lepton (weak) charges, and would allow for the violation of baryon number conservation, which would explain why there is more matter than anti-matter in the universe.