Heavy electroweak boson production in Pb+Pb and $pp$ collisions with ATLAS

Electroweak bosons produced in Pb+Pb collisions are an excellent tool to constrain initial-state effects which affect hard-scattering process rates in nucleon-nucleon interactions. The production yields of massive electroweak bosons, observed via their leptonic decay channels, offer a high-precision test of the binary collision scaling expected in the Pb+Pb system and a way to quantify nuclear modifications of the parton distribution functions. The large sample of Pb+Pb data at $\sqrt{s_\text{NN}} = 5.02$ TeV obtained by the ATLAS experiment in 2015, and the corresponding high-statistics $pp$ data at the same collision energy used as a baseline, allow for a detailed experimental study of these phenomena and comparisons to predictions from a variety of theoretical calculations. This report presents the latest ATLAS results on electroweak boson production, including updated results on $Z$ boson production and high-precision $W$ boson results in Pb+Pb collisions.