Leading logarithms for the nucleon mass

Understand

Within the heavy baryon chiral perturbation theory approach, we have studied the leading logarithm behaviour of the nucleon mass up to four-loop order exactly and we present some results up to six-loop order as well as an all-order conjecture.

• The same methods allow to calculate the main logarithm multiplying the terms with fractional powers of the quark mass.
• We calculate thus the coefficients of $m^{2n+1}\log^{(n-1)}(\mu^2/m^2)$ and $m^{2n+2}\log^n(\mu^2/m^2)$, with $m$ the lowest-order pion mass.
• A side result is the leading divergence for a general heavy baryon loop integral.