Heavy Flavor Azimuthal Correlations in Cold Nuclear Matter

Abstract

Background: It has been proposed that the azimuthal distributions of heavy flavor quark-antiquark pairs may be modified in the medium of a heavy-ion collision. Purpose: This work tests this proposition through next-to-leading order (NLO) calculations of the azimuthal distribution, $d\sigma /d\varphi$, including transverse momentum broadening, employing $<k_T^2>$ and fragmentation in exclusive $Q\bar{Q}$ pair production. While these studies were done for $p+p$, $p+\bar{p}$ and $p+$Pb collisions, understanding azimuthal angle correlations between heavy quarks in these smaller, colder systems is important for their interpretation in heavy-ion collisions. Methods: First, single inclusive $p_T$ distributions calculated with the exclusive HVQMNR code are compared to those calculated in the fixed-order next-to-leading logarithm approach. Next the azimuthal distributions are calculated and sensitivities to $<k_T^2>$, $p_T$ cut, and rapidity are studied at $\sqrt{s}=7$ TeV. Finally, calculations are compared to $Q\bar{Q}$ data in elementary $p+p$ and $p+\bar{p}$ collisions at $\sqrt{s}=7$ TeV and 1.96 TeV as well as to the nuclear modification factor $R_{p\mathrm{Pb}}(p_T)$ in $p+$Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV measured by ALICE. Results: The low $p_T$ ($p_T<10$ GeV) azimuthal distributions are very sensitive to the $k_T$ broadening and rather insensitive to the fragmentation function. The NLO contributions can result in an enhancement at $\varphi \sim 0$ absent any other effects. Agreement with the data was found to be good. Conclusions: The NLO calculations, assuming collinear factorization and introducing $k_T$ broadening, result in significant modifications of the azimuthal distribution at low $p_T$ which must be taken into account in calculations of these distributions in heavy-ion collisions.

29 pages, 21 figures

References in corpus (8)

• New parton distributions for collider physics
• EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions
• Non-Abelian energy loss in cold nuclear matter
• Quarkonium Production in an Improved Color Evaporation Model
• Measurement of prompt D-meson production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Revisiting the D-meson hadroproduction in general-mass variable flavour number scheme
• Measurement of the b-hadron production cross section using decays to D*muX final states in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
• A new correlation method to identify and separate charm and bottom production processes at RHIC

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