Related papers: Challenges with Internal Photons in Constructive Q…
We present the derivation of the Casimir-Polder interactions mediated by a massive photon between two neutral systems described in terms of their atomic polarizability tensors. We find a compact expression for the leading term at large…
In quantum electrodynamics, optical processes are theoretically described by double-sided Feynman diagrams. This formalism is powerful in the case of molecules but proves inappropriate to account for light-matter interactions within complex…
We have investigated phenomenological aspects of kaon photoproduction in three different extreme kinematics. The first kinematics of interest is the threshold region. At the threshold we have investigated the convergence of kaon…
Superradiant scattering, which can be thought of as the wave analogue of the Penrose process is revisited. As is well-known, boson fields display superradiance provided they have frequency in a certain range whereas fermion fields do not. A…
The axion photon system in an external magnetic field, when for example considered with the geometry of the experiments exploring axion photon mixing (which can be represented by a 1+1 effective model) displays a continuous axion-photon…
We discuss recursion relations for scattering amplitudes with massive particles of any spin. They are derived via a two-parameter shift of momenta, combining a BCFW-type spinor shift with the soft limit of a massless particle involved in…
In the first part of this series, we employed the second-order formalism and the ``symbol'' map to construct a particle path-integral representation of the electron propagator in a background electromagnetic field, suitable for open…
In this paper, we present analytical results for the two-loop QCD corrections to the production of two partons or a photon and a parton in hadronic collisions, mediated by loops of massive quarks. These amplitudes involve Feynman integrals…
Soft or collinear photon emission potentially poses numerical problems in the phase-space integration of radiative processes. In this paper, a general subtraction formalism is presented that removes such singularities from the integrand of…
This is the second one of a series of four papers devoted to a first calculation of the scalar and spinor QED four-photon amplitudes completely off-shell. We use the worldline formalism which provides a gauge-invariant decomposition for…
In contrast to wave functions in nonrelativistic quantum mechanics interpreted as probability amplitudes, wave functions in relativistic quantum mechanics have generalized meanings such as charge-density amplitudes, energy-density…
It is well known that instantons are classical topological solutions existing in the context of quantum field theories that lie behind the standard model of particles. To provide a better understanding for the dynamical nature of…
In principle, calculation of a full Green's function in any field theory requires knowledge of the infinite set of multi-point Green's functions, unless one can find some way of truncating the corresponding Schwinger-Dyson equations. For…
We have systematically constructed the general structure of the fermion self-energy and the effective quark propagator in presence of a nontrivial background like hot magnetised medium. This is applicable to both QED and QCD. The hard…
We develop a consistent technique for the calculation of real photon emission in hard exclusive processes, which is based on the background field formalism and allows a convenient separation of hard electromagnetic and soft hadronic…
We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for…
We discuss coherent and incoherent $\phi$ meson photoproduction off the deuteron at low energy and small momentum transfer with the aim to check whether the recent experimental data need for their interpretation the inclusion of exotic…
We consider the influence of photon-initiated processes on high-mass particle production. We discuss in detail the photon PDF at relatively high parton $x$, relevant to such processes, and evaluate its uncertainties. In particular we show…
A minimal truncated set of the integral Dyson-Schwinger equations, in Minkowski spacetime, that allows to explore QED beyond its perturbative solution is derived for general linear covariant gauges. The minimal set includes the equations…
Building on earlier work, the dipole subtraction formalism for photonic corrections is extended to various photon--fermion splittings where the resulting collinear singularities lead to corrections that are enhanced by logarithms of small…