Search results
Results From The WOW.Com Content Network
In quantum mechanics, an energy level is degenerate if it corresponds to two or more different measurable states of a quantum system. Conversely, two or more different states of a quantum mechanical system are said to be degenerate if they give the same value of energy upon measurement. The number of different states corresponding to a ...
Quantum numbers are closely related to eigenvalues of observables. When the corresponding observable commutes with the Hamiltonian, the quantum number is said to be "good", and acts as a constant of motion in the quantum dynamics. To fully specify the state of the electron in a hydrogen atom, four quantum numbers are needed.
For the leptons, the gauge group can be written SU(2) l × U(1) L × U(1) R. The two U(1) factors can be combined into U(1) Y × U(1) l where l is the lepton number. Gauging of the lepton number is ruled out by experiment, leaving only the possible gauge group SU(2) L × U(1) Y. A similar argument in the quark sector also gives the same result ...
Negative refraction. Negative refraction is the electromagnetic phenomenon where light rays become refracted at an interface that is opposite to their more commonly observed positive refractive properties. Negative refraction can be obtained by using a metamaterial which has been designed to achieve a negative value for (electric) permittivity ...
The mass-to-charge ratio ( m / Q) is a physical quantity relating the mass (quantity of matter) and the electric charge of a given particle, expressed in units of kilograms per coulomb (kg/C). It is most widely used in the electrodynamics of charged particles, e.g. in electron optics and ion optics .
Lepton number is an additive quantum number, so its sum is preserved in interactions (as opposed to multiplicative quantum numbers such as parity, where the product is preserved instead). The lepton number is defined by where. n ℓ {\displaystyle n_ {\ell }\quad } is the number of leptons and. n ℓ ¯ {\displaystyle n_ {\overline {\ell }}\quad }
The elementary charge e, i.e. the negative charge on a single electron or the positive charge on a single proton: 10 −18: atto-(aC) ~ 1.8755 × 10 −18 C: Planck charge: 10 −17: 1.473 × 10 −17 C (92 e) – Positive charge on a uranium nucleus (derived: 92 x 1.602 × 10 −19 C) 10 −16: 1.344 × 10 −16 C: Charge on a dust particle in ...
A surface charge is an electric charge present on a two-dimensional surface. These electric charges are constrained on this 2-D surface, and surface charge density, measured in coulombs per square meter (C•m −2 ), is used to describe the charge distribution on the surface. The electric potential is continuous across a surface charge and the ...