Measurement of azimuthal anisotropy of muons from charm and bottom hadrons in Pb+Pb collisions at $$\sqrt{s_{NN}}$$ = 5.02 TeV with the ATLAS detector
Azimuthal anisotropies of muons from charm and bottom hadron decays are measured in Pb+Pb collisions at . The data were collected with the ATLAS detector at the Large Hadron Collider in 2015 and 2018 with integrated luminosities of and , respectively. The kinematic selection for heavy-flavor muons requires transverse momentum and pseudorapidity . The dominant sources of muons in this range are semi-leptonic decays of charm and bottom hadrons. These heavy-flavor muons are separated from light-hadron decay muons and punch-through hadrons using the momentum imbalance between the measurements in the tracking detector and in the muon spectrometers. Azimuthal anisotropies, quantified by flow coefficients, are measured via the event-plane method for inclusive heavy-flavor muons as a function of the muon and in intervals of Pb+Pb collision centrality. Heavy-flavor muons are separated into contributions from charm and bottom hadron decays using the muon transverse impact parameter with respect to the event primary vertex. Non-zero elliptic ( ) and triangular ( ) flow coefficients are extracted for charm and bottom muons, with the charm muon coefficients larger than those for bottom muons for all Pb+Pb collision centralities. The results indicate substantial modification to the charm and bottom quark angular distributions through interactions in the quark-gluon plasma produced in these Pb+Pb collisions, with smaller modifications for the bottom quarks as expected theoretically due to their larger mass.
- Research Organization:
- Harvard Univ., Cambridge, MA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Univ. of Colorado, Boulder, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA)
- Contributing Organization:
- ATLAS Collaboration
- Grant/Contract Number:
- SC0007881; AC02-05CH11231; AC52-07NA27344; SC0018117
- OSTI ID:
- 1635734
- Alternate ID(s):
- OSTI ID: 1650125; OSTI ID: 1688454; OSTI ID: 1814098; OSTI ID: 1972621
- Report Number(s):
- LLNL-JRNL-814868; TRN: US2204126
- Journal Information:
- Physics Letters. B, Vol. 807; ISSN 0370-2693
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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