For Majorana-Wilson lattice fermions in two dimensions we derive a dimer representation. This is equivalent to Gattringer’s loop representation, but is made exact here on the torus. A subsequent dual mapping leads to yet another representation in which a highly efficient Swendsen-Wang type cluster algorithm is constructed. It includes the possibility of fluctuating boundary conditions. It also ...

0031-9007= The low-energy reaction 14C n; 15C provides a rare opportunity to test indirect methods for the determination of neutron capture cross sections by radioactive isotopes versus direct measurements. It is also important for various astrophysical scenarios. Currently, puzzling disagreements exist between the 14C n; 15C cross sections measured directly, determined indirectly, and calculat...

Efforts to unify group-theoretically the standard-model gauge interactions with the generation structure of fermions and their mirror partners should be accompanied with the unification of the corresponding gauge couplings. In this paper the possibility of such a unification is studied and conclusions on possible symmetry-breaking channels and scales, as well as on the fermion content of the th...