Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in 
pp
 Collisions at 
s=13  TeV
 with the ATLAS Detector
The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at ﬃﬃﬃ s p ¼ 13 TeV using a data sample with an integrated luminosity of 150 pb − 1 recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4 – 7 GeV and pseudorapidity range j η j < 2 . 4 . A significant nonzero elliptic anisotropy coefficient v 2 is observed for muons from charm decays, while the v 2 value for muons from bottom decays is consistent with zero within uncertainties.