RAA and v2 of muons from heavy quark decays in 2.76 TeV data with ATLAS

Transcription

1 RAA and v2 of muons from heavy quark decays in 2.76 TeV data with ATLAS Alexander Milov For the ATLAS CollaboraEon

2 Data sample summary Year Species s NN [TeV] L int [nb - 1 ] Triggers 2010 Pb+Pb Minimum Bias 2011 p+p γ, μ, jets, MB 2011 Pb+Pb γ, μ, jets, MB, UPC 2012 p+pb Minimum Bias 2013 p+pb γ, μ, jets, MB, HM, UPC 2013 p+p γ, μ, jets, HM, MB 7, 8 & 13 TeV pp runs, small sample at 2.36 TeV Previous analysis: ATLAS- CONF This analysis: Sasha Milov QM Kobe Island Sept. 29,

3 The ATLAS detector η <2.7 η <4.9 Forward Calorimeter 3.1< η <4.9 η <2.5 Sasha Milov QM Kobe Island Sept. 29,

4 The ATLAS detector p ID Δp calo (p,η,φ) p MS Consistency criterion: Δp = p ID p MS Δp calo (p,η,φ) p ID p ID Sasha Milov QM Kobe Island Sept. 29,

5 Muon ideneficaeon Δp p ID = p ID p MS Δp calo (p,η,φ) p ID Sasha Milov QM Kobe Island Sept. 29,

6 Background removal Δp = p ID p MS Δp calo (p,η,φ) p ID p ID Sasha Milov QM Kobe Island Sept. 29,

7 Background removal Δp = p ID p MS Δp calo (p,η,φ) p ID p ID Sasha Milov QM Kobe Island Sept. 29,

8 Background removal Templates approximates data in pp and in PbPb at all centralities. Sasha Milov QM Kobe Island Sept. 29,

9 Signal fraceon Fraction of muons coming from HF quark decays Sasha Milov QM Kobe Island Sept. 29,

10 Fully corrected spectra Covered range 4<p T <14 GeV Results are in η <1 x20 statistics of 2010 Sasha Milov QM Kobe Island Sept. 29,

11 Nuclear modificaeon factor ATLAS- CONF Significant suppression in central Weak (if any) dependence on p T Good consistency with 2010 data Sasha Milov QM Kobe Island Sept. 29,

12 μ- R AA vs. inclusive h- R AA JHEP09 (2015) 050 Very different behavior compared to the inclusive hadrons: Significantly smaller suppression for muons Strong momentum dependence for hadrons Sasha Milov QM Kobe Island Sept. 29,

13 μ- R AA vs. inclusive jet- R AA PRL 114 (2015) Similar behavior compared to the inclusive jets. (not the same centrality bins!) Comparable degree of suppression Different momenta ranges hard to interpret Sasha Milov QM Kobe Island Sept. 29,

14 μ- R AA vs. b- jet- R AA PRL 113 (2014) Compatible suppression between HF-muon and b-jets Centralities (averaged over measured ranges) are similar Weak (or none) p T dependence in both measurements Sasha Milov QM Kobe Island Sept. 29,

15 μ- R AA mid- rapidity vs. forward PRL 109, (2012) Similar results for mid-rapidity and forward regions. Close (well within errors) results for R AA magnitudes Weak or none p T dependence in both measurements Sasha Milov QM Kobe Island Sept. 29, Overplayed and combined plots are not the official figures.

16 Signal fraceon Fraction of muons coming from HF quark decays Sasha Milov QM Kobe Island Sept. 29,

17 Signal fraceon for different φ- Ψ Fraction of muons coming from HF quark decays Differentially in angle w.r.t. Event Plane Sasha Milov QM Kobe Island Sept. 29,

18 Anisotropy Strong azimuthal anisotropy visible by eye. Sasha Milov QM Kobe Island Sept. 29,

19 v 2 vs. p T Largest v 2 at the lowest measured p T Significant flow even at very high p T Highest amplitudes in 10-40% central Sasha Milov QM Kobe Island Sept. 29,

20 μ- v 2 vs. inclusive h- v 2 : momentum PRC86 (2012) Sasha Milov QM Kobe Island Sept. 29,

21 μ- v 2 vs. inclusive h- v 2 : momentum Muon amplitudes are smaller Is the shape similar? Sasha Milov QM Kobe Island Sept. 29, Overplayed and combined plots are not the official ATLAS figures.

22 μ- v 2 vs. inclusive h- v 2 : centrality PRC86 (2012) Sasha Milov QM Kobe Island Sept. 29,

23 μ- v 2 vs. inclusive h- v 2 : centrality PRC86 (2012) Muon amplitudes are smaller Is the shape similar? Larger difference at lower p T At higher p T the v 2 are not the same, but closer to each over in amplitude and in shape Sasha Milov QM Kobe Island Sept. 29, Overplayed and combined plots are not the official ATLAS figures.

24 Sasha Milov QM Kobe Island Sept. 29, Overplayed and combined plots are not the official ATLAS figures. μ- v 2 mid- rapidity vs. forward arxiv: Muon v 2 is very similar between mid-rapidity and forward region

25 Conclusion ATLAS measured muons coming from HF quark decays in PbPb & 2.76TeV in η <1 in the range 4<p T <14 GeV Residual background is removed on a statistical basis. Measured results are for the Nuclear Modification Factor R AA : centrality-dependent suppression reaching 0.4 in 0-10% weak or no p T -dependence not consistent with suppression of inclusive hadrons consistent with jets (ATLAS) and b-jets (CMS) consistent with forward rapidity (compared ALICE) and second order azimuthal anisotropy v 2 : values up to about 0.08 at p T of 4 GeV in mid-central the v 2 decreases with p T still significant at p T of 10 GeV shape differs from inclusive hadrons (ATLAS) amplitudes better agree at higher p T (ATLAS) consistent with forward rapidity (ALICE) No comparisons to RHIC data are shown wait for Ralf s talk Sasha Milov QM Kobe Island Sept. 29,

26 Thank you for your Kobe, Japan Sasha Milov QM Kobe Island Sept. 29,

27 BKPs Sasha Milov QM Kobe Island Sept. 29,

28 R AA s This slide needs thinking: what else to show? Possibly other experiments too: LHC and RHIC Sasha Milov QM Kobe Island Sept. 29,

29 Nuclear modificaeon factor Sasha Milov QM Kobe Island Sept. 29,

30 Centrality log Z <N part > <N coll > 0-5% 382±0.7% 1683±8% 5-10% 330±1% 1318±8% 10-20% 261±1.5% 923±7% 20-40% 158±2.5% 441±7% 40-80% 46±6% 78±9% MB fracpon 98 ± 2% Sasha Milov QM Kobe Island Sept. 29,