Related papers: Revising the full one-loop gauge prefactor in elec…
High-density fermion matter is meta-stable due to the anomalous non-conservation of baryon and lepton numbers in the electroweak theory. The meta-stable state decays by penetrating the sphaleron barrier separating topologically different…
We study the decay constants and form factors of the ground-state s-wave and low-lying p-wave mesons within a covariant light-front approach. Numerical results of the B to D** transition form factors, where D** denotes generically a p-wave…
Dynamical systems whose symplectic structure degenerates, becoming noninvertible at some points along the orbits are analyzed. It is shown that for systems with a finite number of degrees of freedom, like in classical mechanics, the…
In classical external gauge fields that fall off less fast than the inverse of the evolution parameter (time) of the system the implementability of a unitary perturbative scattering operator ($S$-matrix) is not guaranteed, although the…
A quantitative discussion of nonperturbative effects for the high temperature electroweak phase transition is presented. We propose a method for the computation of the temperature dependent effective scalar potential that takes into account…
A certain vector-tensor (VT) theory is revisited. It was proposed and analyzed as a theory of electromagnetism without the standard gauge invariance. Our attention is first focused on a detailed variational formulation of the theory, which…
The one-loop effective potential calculated for a generic model that originates from 5-dimensional theory reduced down to 4 dimensions is considered. The cut-off and dimensional regularization schemes are discussed and compared. It is…
The application of the background-field method to the electroweak Standard Model and its virtues are reviewed. Special emphasis is directed to the Ward identities that follow from the gauge invariance of the background-field effective…
We compute the complete two-loop O(alpha) Wilson coefficients relevant for radiative decays of the B meson in the SM. This is a necessary step in the calculation of the O(alpha alpha_s^n ln^n m_b/M_W) corrections and improves on our…
We present a fully analytical calculation of the false vacuum decay rate for a self-interacting scalar field in the thin-wall approximation. We obtain the bounce solution, together with the Euclidean action, counter-terms and…
To match the precision of present and future measurements of W-boson production at hadron colliders electroweak radiative corrections must be included in the theory predictions. In this paper we consider their effect on the transverse…
We give a more precise characterisation of the end of the electroweak phase transition in the framework of the effective 3d SU(2)--Higgs lattice model than has been given before. The model has now been simulated at gauge couplings beta_G=12…
In an extension of the Standard Model with a scalar color octet, the possibility of the strongly first-order electroweak phase transition is studied, by examining the finite-temperature effective Higgs potential at the one-loop level. It is…
An independent result for the two loop fermionic contributions to the muon lifetime in the Standard Model is obtained. Deviations are found with respect to \cite{Freitas:2000gg}, which result in a shift of the W boson mass by approximately…
We refine our recent analysis of the electroweak precision data at the \PZO\ pole by including the hadronic decay modes of the \PZO. Within the framework of an effective Lagrangian we parametrize $SU(2)$ violation by the additional…
The full O(alpha_S) transverse momentum distribution for the b -> s+gamma decay is computed. Results are presented in analytic form. An improved expression for the coefficient function taking into account subleading operators is given and…
We complete the two-loop calculation of beta-functions for vacuum expectation values (VEVs) in gauge theories by the missing O(g^4)-terms. The full two-loop results are presented for generic and supersymmetric theories up to two-loop level…
We suggest using Einstein's static universe metric for the metastable state after reheating, instead of the Friedman-Robertson-Walker spacetime. In this case strong static gravitational potential leads to the effective reduction of the…
The kaon electromagnetic (e.m.) form factor is reviewed considering a light-front constituent quark model. In this approach, it is discussed the relevance of the quark-antiquark pair terms for the full covariance of the e.m. current. It is…
The one-loop vacuum energy is explicitly computed for a class of perturbative string vacua where supersymmetry is spontaneously broken by a T-duality invariant asymmetric Scherk-Schwarz deformation. The low-lying spectrum is tachyon-free…