Kinematics (particle physics)
Kinematics in the context of particle physics refers to the study of the motion of particles without considering the forces that cause this motion. It encompasses the analysis of the trajectories, velocities, and momenta of particles as they move through space and time, particularly when they are involved in interactions or collisions. Key concepts in kinematics include: 1. **Position**: The location of a particle in space at a given time, often described using coordinates.
Scattering, absorption, and radiative transfer are fundamental concepts in optics that describe how light interacts with matter. Here's a brief overview of each concept: ### Scattering Scattering refers to the deflection of light rays from a straight path due to interaction with particles or irregularities in a medium. When light encounters small particles (like dust, air molecules, or water droplets), it can be redirected in various directions.
Scattering stubs
Scattering stubs refer to a technique used in various fields such as physics, telecommunications, and engineering, specifically in the study of wave propagation, scattering theory, and antenna design. The term can have slightly different interpretations depending on the context, so here are a couple of common applications: 1. **Physics and Wave Scattering**: In physics, scattering refers to the deflection of waves (like light, sound, or radio waves) when they encounter an obstacle or non-homogeneous medium.
Acoplanarity
Acoplanarity refers to a geometric condition where two or more objects, often in the context of physics or engineering, do not lie in the same plane. This concept is particularly relevant in fields like particle physics, where it may be used to analyze the interaction of particles and their decay products. In practical terms, when dealing with momentum vectors of particles in high-energy physics, acoplanarity tends to describe a situation where the vectors of the outgoing particles do not all fall within the same planar surface.
Born series
The Born series, named after Max Born, refers to a sequence of terms used in quantum mechanics to solve problems involving scattering processes. The Born series is particularly relevant in the context of the scattering theory where it provides an iterative method for calculating the scattering amplitude. The Born series is often expressed as a power series expansion in terms of the interaction potential \( V \) in the context of the time-independent Schrödinger equation.
Bremsstrahlung
Bremsstrahlung is a German term that translates to "braking radiation." It refers to the electromagnetic radiation emitted when charged particles, such as electrons, are accelerated or decelerated, particularly when they pass near atomic nuclei. This process occurs because the change in the velocity of the charged particle results in the emission of energy in the form of radiation, typically X-rays.
Brillouin scattering
Brillouin scattering is a phenomenon in which light (or another electromagnetic wave) interacts with acoustic phonons (sound waves) in a medium, leading to a change in the frequency of the light. This interaction results from the coupling between the electromagnetic wave and the mechanical vibrations of the material.
Chaotic scattering
Chaotic scattering refers to a phenomenon in dynamical systems, particularly in the context of scattering processes, where the trajectories of particles become highly sensitive to initial conditions due to the underlying chaotic dynamics of the system. In chaotic scattering, small changes in the initial conditions of incoming particles can lead to vastly different scattering outcomes.
Coherent backscattering
Coherent backscattering is an optical phenomenon that occurs when coherent light, such as that from a laser, interacts with a disordered medium, such as an opaque or rough surface. This effect is characterized by an increase in the intensity of light that is scattered back in the direction of the incoming beam due to multiple scattering events within the medium. Here are the key points regarding coherent backscattering: 1. **Interference**: The phenomenon arises from the interference of scattered waves.
Core-excited shape resonance
Core-excited shape resonance is a phenomenon observed in the field of quantum mechanics and atomic physics, particularly in the context of electron scattering and the interaction of charged particles with matter. Here’s a summary of the key concepts involved: 1. **Shape Resonance**: This term generally refers to a type of resonance that occurs when an incoming particle experiences a potential barrier and the shape of the potential allows for the temporary trapping of the particle, leading to an enhancement of scattering processes.
Coulomb collision
Coulomb collision refers to the process in which charged particles, such as electrons or ions, interact with each other through the Coulomb force, which is the electromagnetic force between charged particles. This interaction can lead to scattering events where the trajectory and energy of the charged particles can change due to their mutual repulsion (in the case of like charges) or attraction (in the case of opposite charges).
Dalitz plot
A Dalitz plot is a graphical representation used in particle physics to visualize the energy and momentum distribution of decay products from a three-body decay process. It is particularly useful for studying the kinematics of interactions involving three particles resulting from the decay of a parent particle. In a Dalitz plot, the axes typically correspond to the invariant masses of pairs of the decay products.
Debye–Waller factor
The Debye–Waller factor, also known as the thermal factor or the static form factor, quantifies the effect of atomic vibrations on the scattering of neutrons or X-rays by a crystalline material. Specifically, it describes how much the intensity of scattered X-rays or neutrons is reduced due to the thermal motion of atoms within a crystal lattice. In a crystalline solid, atoms are not stationary but vibrate about their equilibrium positions due to thermal energy.
Deep inelastic scattering
Deep inelastic scattering (DIS) is a high-energy particle physics process that provides insights into the internal structure of protons, neutrons, and other hadrons. It involves the scattering of high-energy electrons (or other leptons) off of protons or neutrons, where the energy of the lepton is high enough that it can probe the internal quark and gluon constituents of the target hadron.
Deflection (physics)
In physics, deflection refers to the displacement of a body or a beam from its original position under the influence of an external force. When an object is subjected to forces such as tension, compression, bending, or torsion, it can deform or bend, resulting in a change in its shape or position. Deflection is often measured as the distance that a point on the structure moves from its equilibrium position.
Delbrück scattering
Delbrück scattering is a quantum electrodynamic effect that involves the scattering of photons by the electromagnetic field of a nucleus. It is named after the physicist Max Delbrück, who contributed to the theoretical understanding of the phenomenon. In Delbrück scattering, a high-energy photon can interact with the electric field of a heavy nucleus, leading to an intermediate state where the photon temporarily produces virtual electron-positron pairs.
Differential static light scatter (DSLS) is a technique primarily used in the fields of material science, biophysics, and biochemistry for the analysis of small particles, such as colloids, proteins, or other biomolecules in solution. This method leverages the principles of light scattering to provide information about the size, shape, and distribution of these particles.
Elastic scattering
Elastic scattering is a process in which particles collide without experiencing any change in their internal states or energies. In such interactions, the total kinetic energy of the system is conserved. This means that the incoming particles and the scattered particles retain the same kinetic energy before and after the collision, although their directions may change due to the scattering process.
Electron scattering
Electron scattering is a process in which electrons are directed towards a target material, and their trajectories are altered as a result of interactions with the target’s atoms, nuclei, or electrons. This phenomenon is fundamental in various fields of physics and has important applications in understanding atomic structure, particle physics, and materials science. **Key Concepts:** 1. **Types of Scattering:** - **Elastic Scattering:** The kinetic energy of the electrons is conserved, although their direction may change.
Electron wake
Electron wake refers to the phenomenon that occurs when an electron moves through a medium, such as a plasma or another charged particle system, causing a disturbance in the surrounding environment. As the electron travels, it interacts with other particles, creating a "wake" of electric field disturbances behind it, similar to the way a boat creates waves in water as it moves. This wake can influence the motion of other nearby electrons or charged particles, leading to various collective behaviors.