Measurement of D-meson azimuthal anisotropy in Au + Au 200 GeV collisions at RHIC

详细信息    查看全文

• 作者：Michael Lomnitz^a ; ^b ; for the STAR collaboration
• 关键词：Quark-gluon plasma ; elliptic flow ; Heavy Flavor Tracker
• 刊名：Nuclear Physics A
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：956
• 期：Complete
• 页码：256-259
• 全文大小：174 K

文摘

Heavy quarks are produced through initial hard scatterings and they are affected by the hot and dense medium created in heavy-ion collisions throughout its whole evolution. Due to their heavy mass, charm quarks are expected to thermalize much more slowly than light flavor quarks. The charm quark flow is a unique tool to study the extent of thermalization of the bulk medium dominated by light quarks and gluons. At high p_T, D-meson azimuthal anisotropy is sensitive to the path length dependence of charm quark energy loss in the medium, which offers new insights into heavy quark energy loss mechanisms - gluon radiation vs. collisional processes. We present the STAR measurement of elliptic flow (v₂) of D⁰ and 03ffa402fc89c8aa6964ec742" title="Click to view the MathML source">D^±$D^{\pm }$ mesons in Au+Au collisions at $\sqrt{s_{NN}}=200\text{GeV}$, for a wide transverse momentum range. These results are obtained from the data taken in the first year of physics running of the new STAR Heavy Flavor Tracker detector, which greatly improves open heavy flavor hadron measurements by the topological reconstruction of secondary decay vertices. The D-meson v₂ is finite for p_T>2 GeV/c$p_T>2\text{GeV/c}$ and systematically below the measurement of light particle species at the same energy. Comparison to a series of model calculations favors scenarios where charm flows with the medium and is used to infer a range for the charm diffusion coefficient f99b66" title="Click to view the MathML source">2πTD_s$2\pi T{D}_s$.