Enhanced baryon number violation due to cosmological defects with localized fermions along extra dimension

We propose a new scenario of baryon number violation in models with extra dimensions. In the true vacuum, baryon number is almost conserved due to the localization mechanism of matter fields, which suppresses the interactions between quarks and leptons. We consider several types of cosmological defects in four-dimensional spacetime that shift the center of the localized matter fields, and show that the magnitudes of the baryon number violating interactions are well enhanced. Application to baryogenesis is also discussed.Comment: 12pages, latex2e, added references, to appear in PR

Affleck-Dine baryogenesis in the local domain

For Affleck-Dine baryogenesis to proceed, there must have been two types of phase transitions. One is the destabilized-stabilized phase transition of the flat direction, which is in general induced by the Hubble parameter. The other is the phase transition related to the A-term, which induces the misalignment of the relative phase of the flat direction. In the conventional Affleck-Dine baryogenesis they are supposed to start almost simultaneously. Of course these phase transitions can take place separately, but the latter must not be later than the former because the phase transition of the A-term can not produce any baryon number when there is no condensate of the relative charge. In this paper we try to construct models where the original idea of Affleck-Dine baryogenesis is realized in a different way. We show examples in which the local domain of the false vacuum with the required condensate is formed after inflation and collapses in a safe way so that the domain wall problem is avoided. We also show examples where the phase transition of the A-term starts before the decay of the condensate. As in the conventional Affleck-Dine mechanism, the phase transition of the A-term produces baryon number in the local domain of the condensate. We construct scenarios where our mechanism produces sufficient baryon asymmetry of the Universe.Comment: 18pages, latex2e, to appear in PR

Baryon number violation, baryogenesis and defects with extra dimensions

In generic models for grand unified theories(GUT), various types of baryon number violating processes are expected when quarks and leptons propagate in the background of GUT strings. On the other hand, in models with large extra dimensions, the baryon number violation in the background of a string is not trivial because it must depend on the mechanism of the proton stabilization. In this paper we argue that cosmic strings in models with extra dimensions can enhance the baryon number violation to a phenomenologically interesting level, if the proton decay is suppressed by the mechanism of localized wavefunctions. We also make some comments on baryogenesis mediated by cosmological defects. We show at least two scenarios will be successful in this direction. One is the scenario of leptogenesis where the required lepton number conversion is mediated by cosmic strings, and the other is the baryogenesis from the decaying cosmological domain wall. Both scenarios are new and have not been discussed in the past.Comment: 20pages, latex2e, comments and references added, to appear in PR

Earnings Assimilation of Immigrants in Germany: The Importance of Heterogeneity and Attrition Bias

Heterogeneity in the ethnic composition of Germany's immigrant population renders general conclusions on the degree of economic integration difficult. Using a rich longitudinal data-set, this paper tests for differences in economic assimilation profiles of four entry cohorts of foreign-born immigrants and ethnic Germans. The importance of time-invariant individual unobserved heterogeneity and panel attrition in determining the speed of assimilation is analysed. We find evidence for heterogeneity in the assimilation profiles and for robust assimilation profiles for two entry cohorts only. Omitted variables, systematic sample attrition and the presence of second generation immigrants in the sample influence the speed of assimilation, but do not change the overall picture