Academy of Scientific Research and Technology (ASRT), Cairo, Egypt.
Phys Rev Lett. 2013 Oct 18;111(16):162301. doi: 10.1103/PhysRevLett.111.162301. Epub 2013 Oct 17.
We report on the first measurement of inclusive J/ψ elliptic flow v2 in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at √(s(NN))=2.76 TeV in the rapidity range 2.5<y<4.0. The dependence of the J/ψ v2 on the collision centrality and on the J/ψ transverse momentum is studied in the range 0≤p(T)<10 GeV/c. For semicentral Pb-Pb collisions at √(s(NN))=2.76 TeV, an indication of nonzero v2 is observed with a largest measured value of v2=0.116±0.046(stat)±0.029(syst) for J/ψ in the transverse momentum range 2≤p(T)<4 GeV/c. The elliptic flow measurement complements the previously reported ALICE results on the inclusive J/ψ nuclear modification factor and favors the scenario of a significant fraction of J/ψ production from charm quarks in a deconfined partonic phase.
我们报告了在 LHC 上进行的首例重离子碰撞中包含 J/ψ椭圆流 v2 的测量。该测量是使用 ALICE 探测器在质心能量为 √(s(NN))=2.76 TeV 的 Pb-Pb 碰撞中在 2.5<y<4.0 的快度范围内进行的。研究了 J/ψ v2 对碰撞中心度和 J/ψ横动量的依赖性,范围为 0≤p(T)<10 GeV/c。对于质心能量为 √(s(NN))=2.76 TeV 的半中心 Pb-Pb 碰撞,对于 2≤p(T)<4 GeV/c 的 J/ψ横动量范围内,观察到了非零 v2 的迹象,最大测量值为 v2=0.116±0.046(stat)±0.029(syst)。椭圆流测量补充了之前报道的 ALICE 关于包含 J/ψ核修正因子的结果,并支持了在一个去禁闭的部分子相中存在大量 J/ψ 产生的来自魅夸克的场景。