Measurement of azimuthal anisotropy of muons from charm and bottom hadrons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The elliptic flow of charm and bottom decay muons is measured in high-multiplicity \pp collisions at $\sqrt{s}=13$ TeV with an integrated luminosity of 150 pb$^{-1}$ using 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 muons are further separated into those from charm and bottom decay by incorporating the distance-of-closest-approach to the collision vertex. The measurement is performed for muons over the transverse momentum range 4--7 GeV and pseudorapidity range $|\eta|<2.4$. A significant non-zero elliptic anisotropy coefficient $v_{2}$ is observed for muons from charm decays, while the $v_{2}$ for muons from bottom decays is consistent with zero within uncertainties.