论文标题
$ \ sqrt {s _ {\ rm nn}} $ = 5.02 tev tev
Elliptic flow of electrons from beauty-hadron decays in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV
论文作者
论文摘要
在中间斑点的美容强体衰变中的电子流量（$ | y | $ $ <$ <$ <$ <$ 0.8）在$ \ sqrt {s _ {\ rm nn}} $ = 5.02 tev的PB-PB碰撞中测量了与Alice detector。碰撞中产生的粒子的方位角分布可以通过傅立叶扩展来参数化，其中第二个谐波系数代表椭圆流，$ v _ {\ rm 2} $。 $ v _ {\ rm 2} $从美容 - hadron衰减中的电子系数在横向动量（$ p _ {\ rm {t}} $）中首次测量1.3-6 gev/$ c $在30-50％的中央级别中。与魅力HADRON和其他大多数其他背景来源相比，从美容 - 哈德隆衰减中的电子的测量利用了其较大的平均适当衰减长度$cτ\ $ 500 $μ$ m。发现中部剥离的$ v _ {\ rm 2} $从中间剥落中的电子强体衰变是正面的，其显着性为3.75 $σ$。结果提供了有关介质中美容夸克的热化程度的见解。在高$ p _ {\ rm {t}} $上的测量值，假设美容夸克的完全热化的模型强烈地避免了。运输模型在内，包括美容夸克与扩展的强烈相互交互媒介的实质性相互作用描述了测量。
The elliptic flow of electrons from beauty hadron decays at midrapidity ($|y|$ $<$ 0.8) is measured in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parameterized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, $v_{\rm 2}$. The $v_{\rm 2}$ coefficient of electrons from beauty-hadron decays is measured for the first time in the transverse momentum ($p_{\rm{T}}$) range 1.3-6 GeV/$c$ in the centrality class 30-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length $cτ\approx$ 500 $μ$m compared to that of charm hadrons and most of the other background sources. The $v_{\rm 2}$ of electrons from beauty hadron decays at midrapidity is found to be positive with a significance of 3.75$σ$. The results provide insights on the degree of thermalization of beauty quarks in the medium. A model assuming full thermalization of beauty quarks is strongly disfavoured by the measurement at high $p_{\rm{T}}$, but is in agreement with the results at low $p_{\rm{T}}$. Transport models including substantial interactions of beauty quarks with an expanding strongly-interacting medium describe the measurement.
