Search for a new pseudoscalar decaying into a pair of muons in events with a top-quark pair at Formula Presented with the ATLAS detector

A search for a new pseudoscalar a-boson produced in events with a top-quark pair, where the a-boson decays into a pair of muons, is performed using root s=13 TeV pp collision data collected with the ATLAS detector at the LHC, corresponding to an integrate