⚛ CHIRAL SYMMETRY BREAKING — NJL MODEL
NJL PARAMETERS
Coupling G·Λ²:
2.1
Current quark mass m₀:
0.05
Temperature T/Λ:
0.00
Chemical potential μ/Λ:
0.00
Chiral condensate ⟨ψ̄ψ⟩:
—
Dynamical mass M*:
—
Phase:
—
Symmetry broken:
—
Nambu–Jona-Lasinio (1961):
four-fermion contact interaction models spontaneous chiral symmetry breaking. Below critical coupling Gc, ⟨ψ̄ψ⟩ = 0 (chiral symmetric). Above Gc, ⟨ψ̄ψ⟩ ≠ 0 — quarks acquire dynamical mass ~300 MeV. The "Mexican hat" effective potential shows this is a second-order phase transition. High T or μ restores the symmetry — the QCD chiral phase transition.