Speaker
Alessio Notari
Description
The axion is a hypothetical new particle that could explain the absence of CP violation in QCD and has a very rich cosmological phenomenology. In particular a population of thermally produced axions is expected to exist, in addition to a cold dark matter population. I discuss a new conservative bound on the axion mass, from production in the early universe through scattering with pions below the QCD phase transition. In addition I will show that to further improve the bound and exploit the reach of upcoming cosmological surveys, reliable non-perturbative calculations above the QCD crossover are needed.
