SSP2012 - 5th International Symposium on Symmetries in Subatomic Physics

We study the implications of the global $U(1)_R$ symmetry present in minimal lepton flavor violating extensions of the seesaw. In the context of minimal seesaw setups with a slightly broken $U(1)_R$, it is shown that depending on the $R$-charge assignments two classes of generic models can be identified. Models where the right-handed neutrino masses and the lepton number breaking scale are...

We analyze leptogenesis in the context of seesaw models with almost conserved lepton number, focusing on the L-conserving contribution to the CP asymmetry. We find that, contrary to previous claims, leptogenesis is feasible with heavy neutrino masses ~ 10^6 GeV, well below the gravitino bound for supersymmetric scenarios.

Narrow optical transitions in highly charged ions (HCIs) are of particular interest for metrology and fundamental physics. Atomic clocks could exploit the low susceptibility of HCIs to external electric fields. The highest sensitivity for a changing fine structure constant ever predicted for a stable atomic system is found in Ir$^{17+}$. However, spectroscopy of HCIs is hindered by the large...

The physics goals of the WASA-at-COSY collaboration are based on meson production and decays. One has to analyse different rare decay channels of the mesons to fulfill the physics motivation of finding the symmetry breaking patterns. The combination of high intensity COSY (COoler SYnchrotron) beams and the WASA 4pi detector setup allows us to measure the rare decay channels of light mesons....

Main assumptions of simulation of antiproton and light antinucleus interactions with nuclei are presented. Cross sections of scatterings of the antiparticles by protons and nuclei in the energy range from 100 MeV/c to 1000 GeV/c per anti-nucleon are calculated in the Glauber approximation which provides an excellent description of all known antiproton-nucleus cross sections. The...