  The nucleon and its negative-parity excited states are examined in a maximum
entropy method analysis of QCD sum rules. First, we rederive the parity
projected sum rules for baryons using forward correlation functions. Doing
this, the method is generalized so that higher order operator product expansion
(OPE) terms can be calculated unambiguously. We then apply this approach to the
nucleon channel taking into account all known first order alpha_s corrections
to the Wilson coefficients of the OPE. As these corrections have turned out to
be large, we suppress them by using a phase-rotated Gaussian kernel.
Simultaneously, this phase rotation strongly suppresses the continuum
contribution and improves the convergence of the OPE. The resulting sum rule
has the interesting feature that it is dominated by the term containing the
chiral condensate of dimension 3. Analyzing this sum rule by the maximum
entropy method, we are able to extract information of both the positive and
negative parity states.
