A full set of optimized observables is measured in an angular analysis of the decay B 0 → K ∗ (892) 0μ+μ− using a sample of proton-proton collisions at √𝑠 = 13 TeV, collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 140 fb−1. The analysis is performed in six bins of the squared invariant mass of the dimuon system, 𝑞2, over the range 1.1 < 𝑞2 < 16 GeV2. The results are among the most precise experimental measurements of the angular observables for this decay and are compared to a variety of predictions based on the standard model. Some of these predictions exhibit tension with the measurements
