Analysis of unstable particle with the maximum entropy method in O ( 4 ) φ 4 theory on the lattice
چکیده
Analysis of unstable particle with the maximum entropy method in O(4) φ 4 theory on the lattice Abstract We explore applications of the maximum entropy method (MEM) to determine properties of unstable particles using the four-dimensional O(4) φ 4 theory as a laboratory. The spectral function of the correlation function of the unstable σ particle is calculated with MEM, and shown to yield reliable results for both the mass of σ and the energy of the two-pion state. Calculations are also made for the case in which σ is stable. Distinctive differences in the volume dependence of the σ mass and two-pion energy for the stable and unstable cases are analyzed in terms of perturbation theory.