QCD at non-zero temperature with Wilson fermions on fine lattices

• Applicant: Professor Harvey Byron Meyer, Ph.D.
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2011 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 206495355

In this research project, we investigate bulk properties of strongly interacting matter at non-zero temperature using lattice QCD methods. The subject is motivated by early-universe cosmology and by heavy-ion collision experiments.While many static properties of QCD at non-zero temperature have been determined with controlled errors, much uncertainty remains about the real-time properties of the system, due to the difficulty of calculating them. These include various quasiparticles, particularly in the low-temperature phase, of the photon and dilepton production rate and of transport coefficients. Based on our extensive experience in the field, we want to improve the constraints on real-time properties using newly developed methods within DFG project ME 3622/2-1. Thus we want to carry out a precision calculation of the static and non-static screening masses and amplitudes in the vector channel in the high-temperature phase. This will allow us to estimate the isospin diffusion constant and will stringently test the weak-coupling calculations of the dilepton rate.So far our calculations have been performed in two-flavor O(a) improved Wilson QCD. In the low-temperature phase, the impact of the strange quark could be quite important close to the phase transition. Therefore we will extend our calculations of several quantities to the theory with up, down and strange quarks. These include the dispersion relation of the pion quasiparticle, vector and axial-vector correlators and certain static quantities that constrain the corresponding spectral functions. In addition, in view of the RHIC energy scan and the upcoming CBM experiment, we will carry out similar calculations at imaginary chemical potential in order to probe the effects of a small but non-vanishing net baryon density.

• DFG Programme: Research Grants