Heavy Quark Diffusion Coefficient In Quenched Lattice QCD

In this thesis,we study heavy quark diffusion coefficients in the quenched QCD.All the properties of hardons are encoded in the hadron spectral functions.The heavy quark diffusion coefficient is related to the behavior of vector spectral function at zero frequency according to the linear response theory and Kubo formulae.However,the vector spectral function cannot be computed directly in lattice QCD,and it can be extracted from two-point hadron correlation functions which are computable from lattice QCD.The current-current two-point correlation function in the vector channel,which is commonly used to extract the heavy quark diffusion coefficient,is found to be in-sensitive to the transport peak in the spectral function.Here in this thesis we instead adopt the density-density correlation function in the vector channel,which is more sensitive to the heavy quark diffusion coefficient.We utilize an ansatz based on the linear response theory,and extract the diffusion coefficient from the density-density correlation function computed in quenched lattice QCD using Wilson fermions.In our lattice simulation,we fixed the lattice spacing to 0.009fm,and we vary the N?from 32 to 64.The corresponding temperature range(T=1/(aNT))is from 2.25 Tc to 1.10 Tc.We discuss the temperature dependence of the obtained diffusion coefficient.