Related papers: A global approach to top-quark flavor-changing int…
We demonstrate the feasibility of a nonperturbative analysis of quantum field theory in the worldline formalism with the help of an efficient numerical algorithm. In particular, we compute the effective action for a super-renormalizable…
This is the first in a series of papers, in which we compute the third-order QCD corrections to top-antitop production near threshold in e+ e- collisions. The present paper provides a detailed outline of the strategy of computation in the…
Quantum Chromodynamics (QCD), the gauge field theory of the Strong Interaction, has specific features, asymptotic freedom and confinement, which determine the behaviour of quarks and gluons in particle reactions at high and at low energy…
We investigate the response of a hot gas of quarks to external electric fields via leading-order perturbation theory. In particular, we discuss how equilibrium is maintained in the presence of the electric field and calculate the electric…
Top flavour-changing neutral interactions with a light quark q=u,c and a gauge or Higgs boson are very suppressed within the Standard Model (SM), but can reach observable levels in many of its extensions. We review the possible size of the…
We derive a (Wilsonian) effective field theory of QCD at finite density by integrating out the states in the Dirac sea when the chemical potential $\mu\gg\Lambda_{\rm QCD}$. The quark-gluon coupling is effectively (1+1)-dimensional and the…
Neutral flavor-changing transitions are hugely suppressed in the Standard Model and therefore they are very sensitive to new physics. We consider the decay rate of t->u_i h where u_i=u,c using an effective field theory approach. We perform…
The impact of right-handed currents in both charged- and neutral-current flavour-violating processes is analysed by means of an effective theory approach. More explicitly, we analyse the structure of dimension-six operators assuming a…
We present constraints on Wilson coefficients from a combined fit to data from top-quark and beauty-physics measurements within the Standard Model effective field theory. We consider present data on top-quark pair production and decay,…
We review our perturbative techniques for improved heavy quark actions. A new procedure for computing improvement coefficients is suggested, where the continuum limit of a lattice-regularized theory provides the matching conditions.We also…
The critical value of the atom-field coupling strength for a finite number of atoms is deter- mined by means of both, semiclassical and exact solutions. In the semiclassical approach we use a variational procedure with coherent and…
This article presents a full operator analytical method for studying the quadratic nonlinear interactions in quantum optomechanics. The method is based on the application of higher-order operators, using a six-dimensional basis of second…
Unification-type idea of a basic connection between particle mass and charge quantities is in the spirit of string theory. On the level of phenomenology, this idea means raison d'etre for particle flavor since it requires more than one mass…
Axion models with generation-dependent Peccei-Quinn charges can lead to flavor-changing neutral currents, thus motivating QCD axion searches at precision flavor experiments. We rigorously derive limits on the most general effective…
We study the effective theory of decoupling of a charm quark at low energies. We do this by simulating a model, QCD with two mass-degenerate charm quarks. At leading order the effective theory is a pure gauge theory. By computing ratios of…
Quark-antiquark bound states are examined in the long-range strong-coupling limit with the minimal area law of lattice gauge theory assumed as input. Matrix element relations are established which in the effective theory obtain dynamical…
We examine experimental constraints on scharm-stop flavor mixing in the minimal supersymmetric standard model, which arise from the experimental bounds on squark and Higgs boson masses, the precision measurements of W-boson mass and the…
I discuss the mass parameters appearing in the gauge theory of the strong interactions, concentrating on the two flavor case. I show how the effect of the CP violating parameter $\theta$ is simply interpreted in terms of the state of the…
There is growing interest in the development of a muon collider that would make it possible to produce lepton collisions at energies of several TeV. Among others, there can be significant contributions to electroweak gauge boson, Higgs…
The stationary state solutions of the Ising-type thin films with different layers in the presence of an external oscillatory field have been examined within the effective field theory. The exhibition focuses on understanding of the external…