Maximum Entropy Analysis of Lattice QCD Data Open Access
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An application of the maximum entropy method (MEM) to the analysis of lattice QCD correlation function is presented. We use state-of-the-art MEM by adopting Bryan's method to make the algorithm more efficient. This is achieved by performing singular value decomposition on the kernel of the correlation function which reduces the search space of Q(A)=αS-L from O(103) to O(10). We employ the MEM to study excited states of a number of baryons and mesons by extracting hadronic spectral functions (SPF) from the correlation functions. The LQCD data sets were generated by the χQCD collaboration on a 203×32 lattice with spatial volume of (3.5 fm)3 covering a wide range of 26 quark masses. Several tests are performed to extensively investigate the capability and limitation of the MEM. The first excited states and ground states of N(½±), Λ(½±<\super>), Σ(½±<\super>, Ξ(½+), and Δ(3/2+) baryons, as well as π and K*<\super> mesons are obtained. There are data of other hadron states, however, whose excited states fail to be reliably produced by the MEM. Although we are able to study the excited states in the chiral region with the quark mass as low as 175 MeV, we do not attempt chiral extrapolation because the quality of the data are not sufficiently refined to do reliable extrapolation. The overall results are shown to be consistent with experiment and other works in LQCD and MEM.