PUB - Publikationen an der Universität Bielefeld

The relation between the baryon number in QCD at nonzero chemical potentialand the spectral density of the baryon number Dirac operator, $\gamma_0(D+m)$,is examined. We show that extreme oscillations of the spectral density, causedby the QCD sign problem, are essential for the formation of the average baryonnumber when $\mu>m_\pi/2$. We compute the oscillating region of the spectraldensity using chiral perturbation theory. The extreme oscillations have amicroscopic period and are resolved using random matrix theory.