Spectral function for pions in a magnetic field

This study examines the spectral functions of neutral ( π 0 ) and charged ( π ± ) pions under a uniform magnetic field using the SU(2) Nambu–Jona-Lasinio model with the Ritus method. The analysis highlights the complex interplay of magnetic field effects, thermal influences, and chiral symmetry on meson properties in extreme QCD environments. For π 0 , whose properties are governed by the behavior of its constituent quarks, magnetic field-induced Landau levels lead to a multipeak structure in its spectral function, reflecting stable and resonance solutions that evolve with temperature, showing shifts and critical enhancements near chiral restoration. For π ± , cross terms that come from the asymmetry between the constituent quarks introduce Landau cuts alongside unitary cuts, indicating damping effects, with decay widths narrowing at higher temperatures, suggesting increased stability.