Flavor and Collider constraints for asymmetric dark matter

Abstract

The recent data about the composition of the Universe have shown that approximately 73 % is dark energy contribution, approximately 4% is baryonic matter and near 23 % is dark matter. From these data, it's known that dark matter accounts for about 85% of matter in the universe and that dark matter and baryon abundances are very close to each other: \rho_{DM}/\rho_{B}\approx5. Dark matter is considered as an empirical proof of physics beyond Standard Model (SM) and this fact demonstrates the importance of studying this subject. A natural link between dark matter and baryon densities arises when we consider that dark matter has an asymmetry in the number of density of matter/antimatter like baryons have. So, the proposal for asymmetric Dark Matter is based in the hypothesis that dark matter particle is distinct from the anti-particle and the current abundance is due to entirely one of these species. In general, the scenarios for asymmetric dark matter have two common aspects: the annihilation cross section which is suppressed and the characteristic that DM candidate is light, with a mass similar to the nucleon. And in order to share the primordial dark or baryon asymmetry, the sphalerons and higher dimension operators are important mechanisms. Between them, the higher dimension operators provides a robust fit to connect baryon and dark matter densities with the different possibilities of realization and evading experimental constraints. For asymmetric dark matter models mediated through higher dimension operators, there are important constraints coming from flavor physics, limiting the scale of these operators. The flavor structure of them can lead, for example, to meson mixing, \mu -e conversion or, int the absence of flavor structure, these constraints can put a limit on the mass of the mediator. In this project we will study some of the theoretical framework of the asymmetric dark matter models with emphasis in flavor and collider constraints. (AU)