AI 中文总结
ALICE合作组首次在5.02 TeV Pb-Pb碰撞中测量$\Xi_{c}^0$的产生，发现核修改因子达到3，揭示了强子化和strangeness产生的关键信息。
AI 中文摘要
ALICE合作组报告了在$\mathrm{Pb}-\mathrm{Pb}$碰撞中，$\Xi_{\mathrm c}^{0}$双子粒子的首次测量结果，该碰撞发生在$\sqrt{s_{\mathrm{NN}}}~=5.02~\mathrm{TeV}$。$\Xi_{\mathrm c}^{0}$的产生和横动量（$p_{\mathrm T}$）分布对强子化过程和在高能重离子碰撞中形成的夸克-胶子等离子体中的 strangeness 产生特别敏感。$\Xi_{\mathrm c}^{0}$双子粒子在中间横动量区间（3 < $p_{\mathrm T}$ < 12 GeV/c 和 4 < $p_{\mathrm T}$ < 12 GeV/c）内，在0-10%和30-50%的碰撞中心性区间内被重建，位于中横动量区域（|y| < 0.5）。核修改因子（$R_{\mathrm{AA}}$）在3 < $p_{\mathrm T}$ < 4 GeV/c区间内达到最大值3，这是迄今为止测量到的charm hadrons的最大值。模型预测与测量的$R_{\mathrm{AA}}$相容，但在测量的$p_{\mathrm T}$区间内，它们低估了生产产量以及测量的$\Xi_{\mathrm c}^{0}/\mathrm{D}^{0}$、$\Xi_{\mathrm c}^{0}/\Lambda_{\mathrm c}^{+}$和$\Xi_{\mathrm c}^{0}/\mathrm{D}^{+}_{\mathrm{s}}$产量比值。
英文摘要
The ALICE Collaboration reports the first measurement of the production of prompt $Ξ_{\mathrm c}^{0}$ baryons in nucleus$-$nucleus collisions by analyzing data from $\mathrm{Pb}-\mathrm{Pb}$ collisions at $\sqrt{s_{\mathrm{NN}}}~=5.02~\mathrm{TeV}$. The production and transverse-momentum ($p_{\mathrm T}$) differential spectra of $Ξ_{\mathrm c}^{0}$ are particularly sensitive to the hadronization process and to strangeness production in the quark--gluon plasma formed in high-energy heavy-ion collisions. The $Ξ_{\mathrm c}^{0}$ baryons are reconstructed at midrapidity ($|y|<0.5$) in the transverse-momentum intervals $3<p_{\mathrm T}~<12~\mathrm{GeV}/c$ and $4<p_{\mathrm T}~<12~\mathrm{GeV}/c$ in the 0$-$10\% and 30$-$50\% centrality intervals, respectively. The nuclear modification factor ($R_{\mathrm{AA}}$) reaches values up to 3 in the interval $3<p_{\mathrm T}~<4~\mathrm{GeV}/c$, which is the largest value measured so far for charm hadrons. Model predictions are compatible with the measured $R_{\mathrm{AA}}$, while, in the measured $p_{\mathrm T}$ intervals, they underestimate the production yield as well as the measured $Ξ_{\mathrm c}^{0}/\mathrm{D}^{0}$, $Ξ_{\mathrm c}^{0}/Λ_{\mathrm c}^{+}$, and $Ξ_{\mathrm c}^{0}/\mathrm{D}^{+}_{\mathrm s}$ yield ratios.
Comments19 pages, 3 captioned figures, no table, authors from page 14, submitted to PRL, figures at http://alice-publications.web.cern.ch/node/13443
