Neutral pion decay into νν¯ in dense Skyrmion matter

We study the weak decay of the neutral pion to a neutrino-antineutrino pair, π⁰→νν¯, in the Skyrme model. In baryon-free-space the process is forbidden by helicity while in a dense baryonic medium, the process becomes possible already to leading order in G_F due to the break-down of Lorentz symmetry in the background medium.