Screening masses in thermal and dense medium

Screening masses of different hadronic states are studied in thermal and dense medium on lattice. It has been found that screening masses increase with the temperature. In deconfinement phase, chemical potential enhances the screening masses. We use the normalization with respect to lowest Matsubara frequency to characterize dissolving of hadronic bound states at high temperatures. It has been found that different hadronic states have different dissolving temperatures and their survivals are considerably improved at finite chemical potentials. Spatial correlation functions are often analyzed on lattice, from which screening masses can be constructed [1]. At low temperatures, screening masses are identical with pole masses. The latter can be constructed from temporal correlation functions. Studying temporal correlation functions on lattice is limited due to limitation of lattice temporal dimension. At high temperatures, screening and pole masses have different dependences. In deconfined phase, screening masses are expected to approach lπT , the lowest Matsubara frequency. Therefore, we suggest to use screening masses normalized to lowest Matsubara frequency to determine the temperatures, at which hadronic bound states dissolve into free quarks. In this limit, screening mass does not depend on parent bound states. At very high temperatures, one would expect a universal line of screening masses from different hadronic states. Screening masses can be used to characterize different physical quantities. Their values depend on the properties of the medium. Therefore, screening masses may provide a useful tool to investigate the properties of quark-gluon plasma phase. Values of screening masses can also quantize the response of the medium to weak perturbations, like hadrons. The response likely appears in form of dynamical Debye screening of long-range Coulomb potential. There are different definitions for screening masses. They are related to inverse of Debye screening length. They are the static limits of longitudinal vacuum polarization tensor ∏ 00 (p → 0). In lattice QCD simulations, screening masses can be constructed from exponential falloff of correlators of two Polyakov loops. In this letter, we briefly introduce the results from two flavor lattice simulations at amq = 0.05. The lattice size is 12 2 × 24× 6. Details on numerical simulations can be taken from [2]. To including chemical potentials, we apply method of Taylor expansion at fixed temperature, coupling and bare quark mass. mD(T, μq) T = mD(T ) T ∣