Vibration-rotation and pure rotational data in the X2Σ+ ground state and electronic data from the A2Π – X2Σ+ and B2Σ+ − X2Σ+ transitions of CaH and CaD were used in the quantum-mechanical direct-potential-fit (DPF) analysis to determine an analytic potential energy function for the X2Σ+ ground state of CaH, and a radial correction function for the CaD isotopologue. The potential energy function...

The Ultraviolet-visible (UV) spectra of toluene, ortho-bromo and para-bromo toluene in different solvents have been studied. The electric dipole moments and polarizabilities in the molecular excited electronic states were determined. It was found that the electric dipole moments for the excited states (µ*) and the ground states (µ) of these compounds are equal, and the change in dipole moment i...

We consider the ground state of simple quantum systems coupled to an environment. In general the system is entangled with its environment. As a consequence, even at zero temperature, the energy of the system is not sharp: a projective measurement can find the system in an excited state. We show that energy fluctuation measurements at zero temperature provide entanglement information. For two-st...

Electroluminescence, the emission of light in the presence of an electric current, provides information on the allowed electronic transitions of a given system. It is commonly used to investigate the physics of strongly coupled light-matter systems, whose eigenfrequencies are split by the strong coupling with the photonic field of a cavity. Here we show that, together with the usual electrolumi...

In supersymmetric models with the runaway vacua or with the stable but non-supersymmetric ground state there exist stable field configurations (vacua) which restore one half of supersymmetry and are characterized by constant positive energy density. The formal foundation for such vacua is provided by the central extension of the N = 1 superalgebra with the infinite central charge.

The Isgur-Wise functions for the ground state to ground state semileptonic decays involving b → c transitions are calculated from the (modified) MIT bag model. It is checked that the results for the decays B → Dlν and B → D * lν agree well with experiment. Predictions for the decays Λ b → Λ c lν, B s → D s lν and B s → D * s lν are given and discussed.

We review the calculation of the the effective potential with particular emphasis on cases when the tree potential or the renormalisation-group-improved, radiatively corrected potential exhibits non-convex behaviour. We illustrate this in a simple Yukawa model which exhibits a novel kind of dimensional transmutation. We also review briefly earlier work on the Standard Model. We conclude that, d...