We consider the scattering of quasi-particles off the boundary created during a first order electroweak phase transition. Spatial coherence is lost due to the quasi-quark damping rate, and we show that reflection on the boundary is suppressed, even at treelevel. Simply on CP considerations, we argue against electroweak baryogenesis in the Standard Model via the charge transport mechanism. A CP asymmetry is produced in the reflection properties of quarks and antiquarks hitting the phase boundary. An effect is present at order α 2 W in rate and a regular GIM behaviour is found, which can be expressed in terms of two unitarity triangles. A crucial role is played by the damping rate of quasi-particles in a hot plasma, which is a relevant scale together with M W and the temperature. The effect is many orders of magnitude below what observation requires.

Within an effective field theory derived from string theory, the universal axion has to be coupled to the the gravitational Chern-Simons (gCS) term. During any era when the axion field is varying, the vacuum fluctuation of the gravitational wave amplitude will then be circularly polarised, generating an expectation value for the gCS term. The polarisation may be observable through the Cosmic Microwave Background, and the vacuum expectation value of the gCS term may generate the baryon asymmetry of the Universe. We argue here that such effects cannot be computed without further input from string theory, since the 'vacuum' in question is unlikely to be the field-theoretic one.

We compute the one-loop dispersion relations at finite temperature for quarks, charged leptons and neutrinos in the Minimal Standard Model. The dispersion relations are calculated in two different plasma situations: for a vacuum expectation value υ of the Higgs field υ = 0 (broken electroweak symmetry) and for υ = 0 (unbroken electroweak symmetry). The flavour and chiral non-degeneracy of the quasi-particle spectrum is studied. Numerical results show that the thermal effective masses for fermions in the broken phase have a smaller value than those in the unbroken phase. The temperature dependence of the top quark and electron neutrino thermal effective masses is also presented. Gauge invariance of one-loop dispersion relations is studied.

We study the behaviour of the flavour changing neutral currents in the Left-Right Symmetric Model related to the presence of spontaneous CP phases. To do this, we explore four cases corresponding to combinations of maximal and no CP violation in both the lepton and quark sector. We find that we can constrain the flavour changing neutral currents to the experimental limit, by adjusting the CP -violating phase of the quark sector, opening the possibility to obtain a large CP violation in the lepton sector as well as new Higgs bosons at the electroweak scale.

We study long-range correlations and trends in time series extracted from the data of seismic events occurred from 1973 to 2011 in a rectangular region that contains mainly all the continental part of Colombia. The long-range correlations are detected by the calculation of the Hurst exponents for the time series of interevent intervals, separation distances, depth differences and magnitude differences. By using a modification of the classical R/S method that has been developed to detect short-range correlations in time series, we find the existence of persistence for all the time series considered except for magnitude differences. We find also, by using the DF A until the third order, that the studied time series are not influenced by trends. Additionally, an analysis of the Hurst exponent as a function of the number of events in the time and the maximum window size is presented.