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arXiv 1405.7252hep-phnucl-exnucl-th
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化学非平衡模型下Pb+Pb碰撞$\sqrt{s_{\rm NN}}=2.76$ TeV中奇异粒子的横动量谱

Transverse-momentum spectra of strange particles produced in Pb+Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV in the chemical non-equilibrium model

Viktor Begun, Wojciech Florkowski, Maciej Rybczynski

摘要:

本文分析了在碰撞能为$\sqrt{s_{\rm NN}}=2.76$ TeV的Pb+Pb碰撞中产生的奇异强子的横动量谱。我们的方法结合了化学非平衡的概念与单一冻结的情况。这两个概念是在Cracow模型的框架下实现的,Cracow模型的热力学参数已经在强子多重数比的早期研究中建立。模型的几何参数仅由π介子和K介子的谱拟合得到。利用这些参数,我们得到了质子和$K_S^0$,$K^*(892)^0$,和$ϕ(1020)$介子的光谱的一个很好的描述。对$Λ$、$Ξ$和$Ω$超子也得到了满意的描述.如果我们假设超子是从系统的一个较小的内部部分发射出来的,但在相同的热力学条件下,超子谱的进一步改进是可以实现的。我们的工作不仅包括所有的粒子物种测量到现在为止,在重离子碰撞在LHC的能量,但此外,讨论了粒子生产的中心依赖性。

英文摘要:

We analyze the transverse-momentum spectra of strange hadrons produced in Pb+Pb collisions at the collision energy $\sqrt{s_{\rm NN}}=2.76$ TeV. Our approach combines the concept of chemical non-equilibrium with the single-freeze-out scenario. The two ideas are realized in the framework of the Cracow model, whose thermodynamic parameters have been established in earlier studies of the ratios of hadron multiplicities. The geometric parameters of the model are obtained from the fit to the spectra of pions and kaons, only. Using these parameters, we obtain an excellent description of the spectra of protons and the $K_S^0$, $K^*(892)^0$, and $ϕ(1020)$ mesons. A satisfactory description is also obtained for the $Λ$, $Ξ$ and $Ω$ hyperons. Further improvement of the hyperon spectra may be achieved if we assume that they are emitted from a smaller, internal part of the system but at the same thermodynamic conditions. Our work not only includes all particle species measured up to now in heavy-ion collisions at the LHC energies but, in addition, discusses the centrality dependence of the particle production.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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