High-density fermion matter is meta-stable due to the anomalous non-co
nservation of baryor and lepton numbers in the electroweak theory. The
meta-stable state decays by penetrating the sphaleron barrier separat
ing topologically different vacua. The decay happens locally, and resu
lts in an annihilation of twelve fermions, accompanied by the producti
on of gauge and Higgs bosons. We find numerically local bounce solutio
ns determining the decay rate, which are classical paths in imaginary
time, connecting two adjacent topological sectors. We also follow the
real-time evolution of the bosonic fields after the tunnelling and ana
lyze the spectrum of the created bosons.