February 8th -Thursday- 12:10

"Gerda and MADMAX, searching for the tiniest whispering answer to the biggest questions of nature"

Bela Majorovits

(Max Planck Institut für Physik, Munich)

Why is there a matter dominance in the universe? What is dark matter? Both these questions could be coupled to CP violating processes: 1) Neutrinos could be so called Majorana particles, i.e. identical to their own antiparticles. This would facilitate a Lepton number violating decay of heavy neutrinos in the early universe and could explain why there are more Baryons than anti-Baryons. 2) Axions could result as very weakly interacting particles from a broken "Peccei Quinn" symmetry that drives CP violation in the strong interaction to a value very close to zero. It turns out that axions would have properties that exactly match the requirements for a good dark matter candidate. I will discuss two experiments trying to find the answer about the nature of neutrinos and dark matter: a) The GERDA experiment for the search of neutrinoless double beta decay. Finding this decay would directly imply that neutrinos must have Majorana nature, giving a possible explanation for the matter dominance. b) The MADMAX experiment for the search of dark matter axions. The status of both experimental efforts will be discussed.

Facultad de Ciencias

Seminario de Física Atómica, Molecular y Nuclear

Universidad de Zaragoza