  We present a method to calculate the pion screening mass in 2+1-flavor
lattice QCD to $\mathcal{O}(\mu^2_\ell)$, where $\mu_\ell$ is the isoscalar
chemical potential. Our approach is based on the expression for the free theory
pion screening correlator for massless quarks. We use the Taylor expansion
method to calculate the screening correlator to $\mathcal{O}(\mu^4_\ell)$. We
then extract the $\mathcal{O}(\mu^2_\ell)$ Taylor coefficient of the screening
mass from the Taylor coefficients of the correlator, for two temperatures in
the range 2 - 3 GeV. Our calculations were done using the Highly Improved
Staggered Quark action, and the strange and light quark masses were set
respectively to their physical and nearly physical values, corresponding to
meson masses $M_{\bar{s}s}=686$ MeV and $M_\pi=160$ MeV.

High Energy Physics - Lattice;High Energy Physics - Phenomenology