Azimuthal anisotropy of D meson production in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV
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B. Abelev
- Function : Author
G. Conesa Balbastre
- Function : Author
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J.S. Real
- Function : Author
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- IdHAL : jean-sebastien-real
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C. Roy
- Function : Author
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- IdHAL : christelle-roy
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Laurent Aphecetche
- Function : Author
- PersonId : 2010
- IdHAL : laurent-aphecetche
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- IdRef : 113847653
Guillaume Batigne
- Function : Author
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- IdHAL : guillaume-batigne
- ORCID : 0000-0001-8638-6300
- IdRef : 077207874
Magali Estienne
- Function : Author
- PersonId : 179790
- IdHAL : magali-estienne
- ORCID : 0000-0003-0687-5580
Marie Germain
- Function : Author
- PersonId : 170960
- IdHAL : marie-germain
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- IdRef : 176579958
Gines Martinez Garcia
- Function : Author
- PersonId : 169952
- IdHAL : gines-martinez
- ORCID : 0000-0002-8657-6742
- IdRef : 068952961
Philippe Pillot
- Function : Author
- PersonId : 175815
- IdHAL : ppillot
- ORCID : 0000-0002-9067-0803
Alexandre Shabetai
- Function : Author
- PersonId : 181202
- IdHAL : alexandre-shabetai
- ORCID : 0000-0003-3069-726X
Diego Stocco
- Function : Author
- PersonId : 170966
- IdHAL : diego-stocco
- ORCID : 0000-0002-5377-5163
- IdRef : 204479150
B. Cheynis
- Function : Author
- PersonId : 750577
- IdHAL : brigitte-cheynis
- IdRef : 032215606
Maxime Guilbaud
- Function : Author
- PersonId : 177174
- IdHAL : maxime-guilbaud
- ORCID : 0000-0001-5990-482X
- IdRef : 236157566
Abstract
The production of the prompt charmed mesons D0, D+ and D*+ relative to the reaction plane was measured in Pb-Pb collisions at a centre-of-mass energy per nucleon--nucleon collision of sqrt(sNN) = 2.76 TeV with the ALICE detector at the LHC. D mesons were reconstructed via their hadronic decays at central rapidity in the transverse momentum (pt) interval 2-16 Gev/c. The azimuthal anisotropy is quantified in terms of the second coefficient v_2 in a Fourier expansion of the D meson azimuthal distribution, and in terms of the nuclear modification factor R_AA, measured in the direction of the reaction plane and orthogonal to it. The v_2 coefficient was measured with three different methods and in three centrality classes in the interval 0-50%. A positive v_2 is observed in mid-central collisions (30-50% centrality class), with an mean value of 0.204_{-0.036}^{+0.099},(tot.unc.) in the interval 2 < pt < 6 Gev/c, which decreases towards more central collisions (10-30% and 0-10% classes). The positive v_2 is also reflected in the nuclear modification factor, which shows a stronger suppression in the direction orthogonal to the reaction plane for mid-central collisions. The measurements are compared to theoretical calculations of charm quark transport and energy loss in high-density strongly-interacting matter at high temperature. The models that include substantial elastic interactions with an expanding medium provide a good description of the observed anisotropy. However, they are challenged to simultaneously describe the strong suppression of high-pt yield of D mesons in central collisions and their azimuthal anisotropy in non-central collisions.