2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44022We investigate the magnetic susceptibility of the QCD vacuum, based on the instanton vacuum. Starting from the instanton liquid model for the instanton vacuum, we derive the light-quark partition function $Z[V,T,\hat{m}]$ in the presence of the current quark mass $\hat{m}$ as well as the external Abelian vector and tensor fields. We calculate a two-point correlation function relevant for the magnetic susceptibility and derive it beyond the chiral limit. We obtain for the different flavors the following magnetic susceptibility: $χ_{u,d}< iψ_{u,d}^\dagger ψ_{u,d}>_0 \sim 40\sim45 {\rm MeV}$, while $χ_{s}< iψ_s^\dagger ψ_s >_0 \simeq 6\sim 10 {\rm MeV}$ with the quark condensate $<iψ^\dagger ψ>_0$.13 pages, 2 figuresHigh Energy Physics - Phenomenologytext