Magnetic polarizability of hadrons from lattice QCD in the background field method

We present a calculation of hadron magnetic polarizability using the techniques of lattice QCD. This is carried out by introducing a uniform external magnetic field on the lattice and measuring the quadratic part of a hadron’s mass shift. The calculation is performed on a 24⁴ lattice with standard Wilson actions at beta=6.0 (spacing a=0.1  fm) and pion mass down to about 500 MeV. Results are obtained for 30 particles covering the entire baryon octet (n, p, Σ⁰, Σ^-, Σ⁺, Ξ^-, Ξ⁰, Λ) and decuplet (Δ⁰, Δ^-, Δ⁺, Δ⁺⁺, Σ^*0, Σ^*-, Σ^*+, Ξ^*0, Ξ^*-, Ω^-), plus selected mesons (π⁰, π⁺, π^-, K⁰, K⁺, K^-, ρ⁰, ρ⁺, ρ^-, K^*0, K^*+, K^*-). The results are compared with available values from experiments and other theoretical calculations.