Response of hadrons to the chemical potential at finite temperature

In this work, we have developed a framework for the second order response to the chemical potential and shown the first results of the screening mass of the pseudoscalar meson. As shown in the previous sections, the second order responses are sizable and reveal several characteristics features. The behavior of the responses seems to have close contact to the chiral restoration. It is notable that the single hadronic pole gives a good description of the response as well as the correlator at β = 5.34 (above T/T_c ≈ 1.1) in the pseudoscalar channel. Since the present study is the first trial, our simulations have been performed on a rather small lattice. Further investigations on larger lattices are required. A study of the chemical potential responses of the nucleon is also an interesting subject. Similarly, those of the quark condensate are even more important. An exploratory study is in progress.