相关论文: Quantum theory of transition radiation and transit…
If the neutrino has a finite mass and a magnetic moment it would produce transition radiation when crossing the interface between two media. We found that the probability of transition radiation is larger by an order of magnitude using the…
Electron-positron pair creation by multiphoton absorption in the collision of a relativistic electron with a strong laser beam is calculated within laser-dressed quantum electrodynamics. Total production rates, positron spectra, and…
QED theory of multiphoton cascade transitions in atoms and ions is developed. This theory allows for the accurate description of the process important for astrophysical studies of the cosmological hydrogen recombination. In particular the $…
QED theory of multiphoton cascade transitions in atoms and ions is developed. In particular the $ 3s\rightarrow1s+2\gamma $, $ 4s\rightarrow1s+2\gamma $ and $ 3p\rightarrow1s+3\gamma $ processes are considered. Two different approaches…
We demonstrate that the transition photon radiation and pair creation can be interpreted as a diffractive phenomenon in terms of the light-cone wave functions in a way similar to the Good-Walker approach [6] to the diffraction dissociation.…
The status of theoretical predictions for top-quark pair production at hadron colliders is reviewed, focusing on the total cross section, differential distributions, and the description of top-quark production and decay including off-shell…
A rigorous QED theory of the spectral line profiles is applied to transition probabilities in few-electron highly charged ions. Interelectron interaction corrections are included as well as radiative corrections. Parity nonconserving (PNC)…
We apply quantum rate theory to calculate the transition rates as hydrogen or deuterium atoms escape from a vacancy trap in iron into a neighbouring metastable site. We determine transition rates and corresponding activation energies over a…
A canonical formalism is presented which allows for investigations of quantum radiation induced by localized, smooth disturbances of classical background fields by means of a perturbation theory approach. For massless, non-selfinteracting…
We give an exact, analytic, and manifestly gauge invariant account of pair production in combined longitudinal and transverse electromagnetic fields, both depending arbitrarily on lightfront time. The instantaneous, nonperturbative…
Self-energy and vacuum polarization effects in quantum electrodynamics (QED) are calculated for the supercritical Coulomb field, where Dirac energy levels become embedded in the negative-energy continuum. In this regime, the quantum vacuum…
Transition radiation is a fundamental process of light emission and occurs whenever a charged particle moves across an inhomogeneous region. One feature of transition radiation is that it can create light emission at arbitrary frequency…
In this talk we present the current status of the theoretical description of the production of top-quark pairs at the LHC, detailing recent progress for predictions at the stable-top level as well as for predictions that include the decay…
Modern observations and models of various astrophysical objects suggest that many of their physical parameters fluctuate substantially at different spatial scales. The rich variety of the emission processes, including Transition Radiation…
The explicit expression for the inclusive probability to record a photon created in transition radiation from a one Dirac particle wave packet traversing an ideally conducting plate is derived in the leading order of perturbation theory.…
Two quantum systems, each described as a random-matrix ensemble. are coupled to each other via a number of transition states. Each system is strongly coupled to a large number of channels. The average transmission probability is the product…
In this talk I will give an overview on theoretical aspects of top quark physics. The focus lies on top pair production and single top production.
A model is developed which allows the investigation and classification of the pairing phase transition in atomic nuclei. The regions of the parameter space are discussed for which a pairing phase transition can be observed. The model…
Transition State Theory forms the basis of computing reaction rates in chemical and other systems. Recently it has been shown how transition state theory can rigorously be realized in phase space using an explicit algorithm. The…
The theory of coherent transition radiation produced by a relativistic electron beam during its extraction from a microtron is established. Expressions for the beam form factor, spectral-angular and angular distribution of coherent…