Abstract for the talk on 04.12.2018 (17:00 h)

Colloquium of the Faculty of Physics and Geosciences

Gerrit Schierholz (Deutsches Elektronen - Synchrotron (DESY))
Towards a Quantitative Understanding of the Stability of Matter

The universe as we know is highly sensitive to the size of the neutron (n) - proton (p) mass difference. If it would be larger than the binding energy of the deuteron, no fusion would take place. If it would be only a little smaller, all hydrogen would have been burned. Though it is one of the most consequential parameters of physics, the n - p mass difference is not a primary quantity. The relevant theories for the calculation are QCD and QED. With strong and electromagnetic effects being of the same order of magnitude and strongly correlated, this makes a nonperturbative evaluation necessary. For the first time both QCD and QED are now included in the same nonperturbative calculation, which allows us to predict isospin breaking effects in the meson, baryon and quark sectors from first principles, and in particular the n - p mass difference.

 

06.12.2018, 02:31