"Table 19" of "Multi-strange baryon production in p-Pb collisions at $\sqrt{s_\mathbf{NN}}=5.02$"

CERN-LHC. The multi-strange baryon yields in Pb--Pb collisions have been shown to exhibit an enhancement relative to pp reactions. In this work, $\Xi$ and $\Omega$ production rates have been measured with the ALICE experiment as a function of transverse momentum, ${p_{\rm T}}$, in p-Pb collisions at a centre-of-mass energy of ${\sqrt{s_{\rm NN}}}$ = 5.02 TeV. The results cover the kinematic ranges 0.6 GeV/$c<{p_{\rm T}} <$7.2 GeV/$c$ and 0.8 GeV/$c<{p_{\rm T}}<$ 5 GeV/$c$, for $\Xi$ and $\Omega$ respectively, in the common rapidity interval -0.5 $<{y_{\rm CMS}}<$ 0. Multi-strange baryons have been identified by reconstructing their weak decays into charged particles. The ${p_{\rm T}}$ spectra are analysed as a function of event charged-particle multiplicity, which in p-Pb collisions ranges over one order of magnitude and lies between those observed in pp and Pb-Pb collisions. The measured ${p_{\rm T}}$ distributions are compared to the expectations from a Blast-Wave model. The parameters which describe the production of lighter hadron species also describe the hyperon spectra in high multiplicity p-Pb. The yield of hyperons relative to charged pions is studied and compared with results from pp and Pb-Pb collisions. A statistical model is employed, which describes the change in the ratios with volume using a canonical suppression mechanism, in which the small volume causes a species-dependent relative reduction of hadron production. The calculations, in which the magnitude of the effect depends on the strangeness content, show good qualitative agreement with the data.

欧洲核子研究中心大型强子对撞机（CERN-LHC）相关研究表明，铅-铅（Pb-Pb）碰撞中的多奇异重子产额相较于质子-质子（pp）反应呈现出显著增强效应。本工作利用ALICE实验装置，对质心系能量√s_NN = 5.02 TeV的质子-铅（p-Pb）碰撞，测量了Ξ和Ω超子的产生率随横动量（transverse momentum，p_T）的分布。其中，Ξ超子的测量覆盖运动学区间0.6 GeV/c < p_T <7.2 GeV/c，Ω超子则为0.8 GeV/c < p_T <5 GeV/c，所有测量均处于共同的CMS坐标系快度区间-0.5 < y_CMS <0范围内。多奇异重子通过重构其弱衰变至带电粒子的末态过程得以鉴别。本研究针对p_T谱开展了关于事件带电粒子多重数的依赖关系分析：p-Pb碰撞中的事件带电粒子多重数跨度达一个数量级，且介于pp与Pb-Pb碰撞的观测多重数区间之内。将实测得到的p_T分布与爆炸波（Blast-Wave）模型的理论预期进行对比后发现，描述较轻强子种类产生的模型参数，同样可对高多重数p-Pb碰撞中的超子谱实现良好描述。此外，本研究还探究了超子相对于带电π介子的产额比，并将其与pp和Pb-Pb碰撞的已有测量结果进行对比。我们采用了统计模型，该模型借助正则抑制（canonical suppression）机制解释产额比随碰撞系统体积的变化规律：即较小的碰撞体积会导致强子产生出现种类依赖的相对压低效应。计算结果显示，该抑制效应的强弱与粒子的奇异数含量直接相关，且与实验数据具备良好的定性一致性。