Search results
Results From The WOW.Com Content Network
The S-matrix is closely related to the transition probability amplitude in quantum mechanics and to cross sections of various interactions; the elements (individual numerical entries) in the S-matrix are known as scattering amplitudes. Poles of the S-matrix in the complex-energy plane are identified with bound states, virtual states or resonances.
The Scattering transfer parameters or T-parameters of a 2-port network are expressed by the T-parameter matrix and are closely related to the corresponding S-parameter matrix. However, unlike S parameters, there is no simple physical means to measure the T parameters in a system, sometimes referred to as Youla waves.
In S-matrix theory, the S-matrix relates the infinite past to the infinite future in one step, without being decomposable into intermediate steps corresponding to time-slices. This program was very influential in the 1960s, because it was a plausible substitute for quantum field theory , which was plagued with the zero interaction phenomenon at ...
In quantum physics, the scattering amplitude is the probability amplitude of the outgoing spherical wave relative to the incoming plane wave in a stationary-state scattering process. [1] At large distances from the centrally symmetric scattering center, the plane wave is described by the wavefunction [ 2 ]
where (,) is the so-called scattering amplitude, which is in this case only dependent on the elevation angle and the energy. In conclusion, this gives the following asymptotic expression for the entire wave function:
In quantum field theory, the Lehmann–Symanzik–Zimmermann (LSZ) reduction formula is a method to calculate S-matrix elements (the scattering amplitudes) from the time-ordered correlation functions of a quantum field theory.
Using the first Born approximation, it has been shown that the scattering amplitude for a scattering potential () is the same as the Fourier transform of the scattering potential [3]. Using this concept, the electronic analogue of Fourier optics has been theoretically studied in monolayer graphene. [ 4 ]
The most successful S-matrix approach centered on the narrow-resonance approximation, the idea that there is a consistent expansion starting from stable particles on straight-line Regge trajectories. After many false starts, Richard Dolen, David Horn , and Christoph Schmid understood a crucial property that led Gabriele Veneziano to formulate a ...