Speaker
Description
The nucleon self-energy is calculated in SU(2) covariant chiral perturbation theory to study the pion mass dependence of the nucleon mass up to chiral order $O(q^6)$, i.e., including two-loop diagrams.
The contributions of the diagrams are expressed by a small set of (scalar) master integrals, which are evaluated by means of the chiral expansion in $d$ dimensions, using the strategy of regions to differentiate between the infrared singular and regular part.
The extended on-mass-shell renormalization scheme is applied, making the renormalized expressions consistent with the power counting.
In addition, the renormalization is discussed in the off-shell case, taking the nucleon mass in the chiral limit as renormalized nucleon mass.
For the final result not to rely on the chiral ($1/m$) expansion, the master integrals are computed numerically.
