Meson screening mass at finite chemical potential

Abstract

Knowledge of the screening masses at finite chemical potential can provide insight into the nature of the QCD phase diagram. However, lattice studies at finite chemical potential suffer from the well-known issue of the sign problem, which has made the calculation of observables such as screening correlators and screening masses at finite chemical potential quite challenging. One way to proceed is by expanding the observable in a Taylor series in the chemical potential and hence calculating the finite-density corrections to the observable. In this talk, we will use this approach to calculate the screening mass of the pseudoscalar meson at finite temperatures and chemical potential by expanding the screening correlator in a Taylor series in the chemical potential. We will present our results for the second derivative of the screening mass w.r.t. the chemical potential. Our calculation was done on 64 3 × 8 lattices generated using the (2+1) HISQ/tree action.

Pion screening mass at finite chemical potential

“…In deriving equation (4.6) and equation (4.7), we only considered contributions from a single state. Previously, we had derived equations similar to the above equations, but additionally including the contributions from the first excited state as well [48]. The excited states contribute only at shorter distances ẑ 2.25.…”

QCD thermodynamics: an overview of recent progress

“…Progress towards the determination, using Taylor expansion, of the dependence on a nonzero isoscalar chemical potential of screening masses in QCD (specifically that of the pseudoscalar meson) is reported in Ref. [85] where both the free and the interacting theory are discussed, and the screening mass is allowed to take complex values motivated by the free theory analytical expression for the screening correlator showing an oscillatory behavior that suggests a complex screening mass.…”

A New Way to Compute the Pseudoscalar Screening Mass at Finite Chemical Potential

“…We will also present a method to calculate the pion screening mass to O (𝜇 2 ℓ ) from the Taylor expansion of the screening correlator. We had earlier presented some preliminary results at the previous Lattice conference [10]. A complete discussion of our method and results can be found in our paper [11].…”