Calculation of the transition amplitude using differential forms for the simplest electron-electron interaction

2021 ◽  
pp. 413629
Author(s):  
Kondo Shin-ichiro
Keyword(s):  
Differential Forms ◽  
Transition Amplitude ◽  
Electron Interaction

Resonant detection and production of axions with atoms

2018 ◽  
Vol 33 (31) ◽  
pp. 1844030 ◽  
Author(s):  
V. V. Flambaum ◽  
H. B. Tran Tan ◽  
I. B. Samsonov ◽  
Y. V. Stadnik ◽  
D. Budker
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Radiation ◽  
Transition Amplitude ◽  
Forward Direction ◽  
Interaction Constant ◽  
Electron Interaction ◽  
First Order ◽  
Atomic Medium ◽  
Molecular Transition ◽  
Conventional Scheme

The axions and axion-like particles can be detected via a resonant atomic or molecular transition induced by axion absorption. The signal obtained in this process is second order in the axion-electron interaction constant and hence small. In this chapter, it is demonstrated that this signal may become first order in the axion-electron interaction constant if we allow the interference between the axion-induced transition amplitude and the transition amplitude induced by the electromagnetic radiation. Additionally, we show that the conventional scheme of producing axions from photons in a magnetic field may be improved if the field is replaced by an atomic medium in which photons scattering off the atoms in the forward direction are transformed into axions.

Quantum mechanics

2018 ◽  
Author(s):  
Michael Kachelriess
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Mechanics ◽  
Relativistic Quantum ◽  
Transition Amplitude ◽  
External Source ◽  
Quantum Field ◽  
Damping Term ◽  
Relativistic Quantum Theory ◽  
Generating Functional

After a brief review of the operator approach to quantum mechanics, Feynmans path integral, which expresses a transition amplitude as a sum over all paths, is derived. Adding a linear coupling to an external source J and a damping term to the Lagrangian, the ground-state persistence amplitude is obtained. This quantity serves as the generating functional Z[J] for n-point Green functions which are the main target when studying quantum field theory. Then the harmonic oscillator as an example for a one-dimensional quantum field theory is discussed and the reason why a relativistic quantum theory should be based on quantum fields is explained.

scholarly journals Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS

2019 ◽  
Vol 199 ◽  
pp. 01014
Author(s):  
K. Piscicchia ◽  
M. Bazzi ◽  
G. Belloti ◽  
A. M. Bragadireanu ◽  
D. Bosnar ◽  
...  
Keyword(s):  
Cross Sections ◽  
Transition Amplitude ◽  
Nuclear Interaction ◽  
Branching Ratios ◽  
Analysis Procedure ◽  
Low Energy ◽  
Carbon Target ◽  
Pure Carbon ◽  
Nuclear Targets ◽  
Mass Spectroscopic Study

The AMADEUS experiment at the DAΦNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K− interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K− absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K− captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K− nuclear interaction. The first measurement of the non-resonant transition amplitude $\left| {{A_{{K^ - }n \to \Lambda {\pi ^ - }}}} \right|$ at $\sqrt s = 33\,MeV$ below the K̄N threshold is presented, in relation with the Λ(1405) properties studies. The analysis procedure adopted in the serarch for K− multi-nucleon absorption cross sections and Branching Ratios will be also described.

scholarly journals Interplay of spin–orbit coupling and Coulomb interaction in ZnO-based electron system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. Maryenko ◽  
M. Kawamura ◽  
A. Ernst ◽  
V. K. Dugaev ◽  
E. Ya. Sherman ◽  
...  
Keyword(s):  
Coulomb Interaction ◽  
High Mobility ◽  
Electron System ◽  
Orbit Coupling ◽  
Electron Interaction ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Strong Electron ◽  
Strongly Coupled ◽  
Dimensional Electron System

AbstractSpin–orbit coupling (SOC) is pivotal for various fundamental spin-dependent phenomena in solids and their technological applications. In semiconductors, these phenomena have been so far studied in relatively weak electron–electron interaction regimes, where the single electron picture holds. However, SOC can profoundly compete against Coulomb interaction, which could lead to the emergence of unconventional electronic phases. Since SOC depends on the electric field in the crystal including contributions of itinerant electrons, electron–electron interactions can modify this coupling. Here we demonstrate the emergence of the SOC effect in a high-mobility two-dimensional electron system in a simple band structure MgZnO/ZnO semiconductor. This electron system also features strong electron–electron interaction effects. By changing the carrier density with Mg-content, we tune the SOC strength and achieve its interplay with electron–electron interaction. These systems pave a way to emergent spintronic phenomena in strong electron correlation regimes and to the formation of quasiparticles with the electron spin strongly coupled to the density.

scholarly journals Elastic Electron Scattering from Methane Molecule in the Energy Range from 50–300 eV

2021 ◽  
Vol 22 (2) ◽  
pp. 647
Author(s):  
Jelena Vukalović ◽  
Jelena B. Maljković ◽  
Karoly Tökési ◽  
Branko Predojević ◽  
Bratislav P. Marinković
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Electron Gun ◽  
Methane Molecule ◽  
Edge Plasma ◽  
Electron Interaction ◽  
Outer Planet ◽  
Elastic Electron

Electron interaction with methane molecule and accurate determination of its elastic cross-section is a demanding task for both experimental and theoretical standpoints and relevant for our better understanding of the processes in Earth’s and Solar outer planet atmospheres, the greenhouse effect or in plasma physics applications like vapor deposition, complex plasma-wall interactions and edge plasma regions of Tokamak. Methane can serve as a test molecule for advancing novel electron-molecule collision theories. We present a combined experimental and theoretical study of the elastic electron differential cross-section from methane molecule, as well as integral and momentum transfer cross-sections in the intermediate energy range (50–300 eV). The experimental setup, based on a crossed beam technique, comprising of an electron gun, a single capillary gas needle and detection system with a channeltron is used in the measurements. The absolute values for cross-sections are obtained by relative-flow method, using argon as a reference. Theoretical results are acquired using two approximations: simple sum of individual atomic cross-sections and the other with molecular effect taken into the account.

scholarly journals A Complete CDW Theory for the Single Ionization of Multielectronic Atoms by Bare Ion Impact

Atoms ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Juan M. Monti ◽  
Michele A. Quinto ◽  
Roberto D. Rivarola
Keyword(s):  
Transition Amplitude ◽  
Emission Spectra ◽  
Heavy Ion ◽  
Distorted Wave ◽  
Single Ionization ◽  
Complete Form ◽  
Active Electron ◽  
Ion Impact ◽  
Range Part ◽  
The Continuum

A complete form of the post version of the continuum distorted wave (CDW) theory is used to investigate the single ionization of multielectronic atoms by fast bare heavy ion beams. The influence of the non-ionized electrons on the dynamic evolution is included through a residual target potential considered as a non-Coulomb central potential through a GSZ parametric one. Divergences found in the transition amplitude containing the short-range part of the target potential are avoided by considering, in that term exclusively, an eikonal phase instead of the continuum factor as the initial channel distortion function. In this way, we achieve the inclusion of the interaction between the target active electron and the residual target, giving place to a more complete theory. The present analysis is supported by comparisons with existing experimental electron emission spectra and other distorted wave theories.

scholarly journals On polytopes and generalizations of the KLT relations

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Nikhil Kalyanapuram
Keyword(s):  
Scattering Amplitudes ◽  
Large Class ◽  
Moduli Space ◽  
Differential Forms ◽  
Natural Generalization ◽  
Intersection Theory ◽  
Hyperplane Arrangements ◽  
Number Of Solutions ◽  
Scalar Theories ◽  
Double Copy

Abstract We combine the technology of the theory of polytopes and twisted intersection theory to derive a large class of double copy relations that generalize the classical relations due to Kawai, Lewellen and Tye (KLT). To do this, we first study a generalization of the scattering equations of Cachazo, He and Yuan. While the scattering equations were defined on ℳ0, n — the moduli space of marked Riemann spheres — the new scattering equations are defined on polytopes known as accordiohedra, realized as hyperplane arrangements. These polytopes encode as patterns of intersection the scattering amplitudes of generic scalar theories. The twisted period relations of such intersection numbers provide a vast generalization of the KLT relations. Differential forms dual to the bounded chambers of the hyperplane arrangements furnish a natural generalization of the Bern-Carrasco-Johansson (BCJ) basis, the number of which can be determined by counting the number of solutions of the generalized scattering equations. In this work the focus is on a generalization of the BCJ expansion to generic scalar theories, although we use the labels KLT and BCJ interchangeably.

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