Related papers: The $E1$ & $M1$ Spontaneous Decay Rates for an Emi…
Modifications of the mu+ lifetime in matter due to muonium (M = mu+ e-) formation and other medium effects are examined. Muonium and free mu+ decay spectra are found to differ at O(alpha m_e/m_mu) from Doppler broadening and O(alpha^2…
Quantum mechanical treatment of light inside dielectric media is important to understand the behavior of an optical system. In this paper, a two-level atom embedded in a rectangular waveguide surrounded by a perfect electric conductor is…
We present a non-perturbative calculation of the form factors which contribute to the amplitudes for the radiative decays $P\to \ell \bar \nu_\ell \gamma$, where $P$ is a pseudoscalar meson and $\ell$ is a charged lepton. Together with the…
In the first part of the present work, the correction to photon emission rate of an oscillating two-level atom in the presence of electromagnetic quantum vacuum field has been investigated for two different configurations: (i) Atom is…
The role of spontaneous emission in the interaction between a two-level atom and a pumped micro-cavity in the strong coupling regime is discussed in this paper. Especially, using a quantum Monte-Carlo simulation, we investigate atomic…
We study the baryon density dependence of the vector meson spectrum using the D4/D6 system together with the compact D4 baryon vertex. We find that the vector meson mass decreases almost linearly in density at low density for small quark…
We evaluate the width of the $\omega$ meson in nuclear matter. We consider the free decay mode of the $\omega$ into three pions, which is dominated by $\rho \pi$ decay, and replace the $\rho$ and $\pi$ propagators by their medium modified…
We have calculated the decay $\tau \rightarrow \nu \pi(K) \gamma$. We present the photon energy spectrum, the meson-photon invariant mass spectrum and the integrated rate as a function of a photon energy cut or an invariant mass cut. Both…
The rate of monopole decay into a dyon and an electron in an inhomogeneous external electric field is calculated by semiclassical methods. Comparison is made to an earlier result where this quantity was calculated for a constant field.…
The behavior of a two level atom in a half-cavity, i.e. a cavity with one mirror, is studied within the framework of a one dimensional model with respect to spontaneous decay and resonance fluorescence. The system under consideration…
The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in the framework of the Standard Model in external electromagnetic fields of various configurations: constant crossed field, constant uniform…
We present a comprehensive study of internal quality factors in superconducting stub-geometry 3-dimensional cavities made of aluminum. We use wet etching, annealing and electrochemichal polishing to improve the as machined quality factor.…
The calculation of the $\mu$ decay is performed in V-A theory taking into account that, in agreement with the observation of the oscillations, the neutrinos must be massive. Provided that the masses of the electron and muon neutrinos are…
We study quantum dissipative effects due to the non-relativistic, bounded, accelerated motion of a single neutral atom in the presence of a planar perfect mirror, i.e. a perfect conductor at all frequencies. We consider a simplified model…
The decay constants of pseudoscalar mesons are calculated in a relativistic quark model which assumes that mesons are made of a valence quark antiquark pair and of an effective vacuum like component. The results are given in terms of quark…
We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by…
The rate of spontaneous emission is known to depend on the environment of a light source, and the enhancement of one-photon emission in a resonant cavity is known as the Purcell effect. Here we develop a theory of spontaneous two-photon…
We address the time decay of the Loschmidt echo, measuring sensitivity of quantum dynamics to small Hamiltonian perturbations, in one-dimensional integrable systems. Using semiclassical analysis, we show that the Loschmidt echo may exhibit…
We study radiative corrections to the decay rate of false vacua, paying particular attention to the renormalization-scale dependence of the decay rate. The decay rate exponentially depends on the bounce action. The bounce action itself is…
Divergences that occur in density matrices of decay and scattering processes are shown to be regularized by tracing and unitarity or the optical theorem. These divergences are regularized by the lifetime of the decaying particle or the…