Complex 2D Matrix Model and Its Application to Nc-dependence of Hadron   Structures
  We study the internal structure of resonance states in a complex 2D matrix model. We show that the geometry with "exceptional points" in the complex-parameter space can be useful to discuss parameter dependence of the structures within real-parameter subspace. By applying the model to hadron physics, we consider the Nc-dependence of hadron structures from the geometry on the complex-Nc plane. 
Kanabu Nawa, Sho Ozaki, Hideko Nagahiro, Daisuke Jido, Atsushi Hosaka
hep-ph hep-th quant-ph