  We show that the coherent oscillations of the e.m. field induced by the
collective quantum fluctuations of the nuclear matter field associated with the
giant resonances, with frequencies $\omega_{A}\simeq 78A^{-{1/3}}$ MeV, give
rise to a significant $(e^+e^-)$ pair production in high energy Heavy Ion
collisions. The approximate parameterless calculation of such yield is in good
agreement with recent experimental observations.
