Phase diagram of the G(2) Higgs model and G(2)-QCD
  We investigate gauge theories based on the smallest exceptional simple lie group G(2). Our first model considered here is G(2) Yang-Mills coupled to a fundamental Higgs field. In 4 spacetime dimensions we explore the phase diagram of the theory, showing that at larger Higgs masses the first order deconfinement phase transition turns into a crossover and therefore connects the low temperature confined phase with the high temperature deconfined phase. The second model investigated is G(2) Yang-Mills coupled to fundamental fermions. It shares many features with QCD, especially fermionic baryons, but due to the absence of the fermion sign problem we can investigate this theory with Monte Carlo techniques even at low temperature and high baryonic density. First results on small lattices are presented. 
Bj\"orn H. Wellegehausen
hep-lat hep-th