热展宽对重离子碰撞中轻强子产生的影响
Effect of Thermal Broadening on Light Hadron Production in Heavy-Ion Collisions
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中文总结 AI 辅助
本研究将FastReso框架推广到有限宽度谱函数共振，结合blast-wave拟合分析LHC重离子碰撞数据，发现热展宽矢量介子可减小软π介子模型与数据的偏差但未完全解决软π介子难题。
中文摘要 AI 辅助
重离子碰撞中测得的强子产额可通过接近QCD赝临界转变温度下的热粒子产生得到很好描述。然而，若粒子在热平衡中产生，则必须考虑介质效应，例如其谱函数的展宽。本工作首次研究轻矢量介子谱函数的热展宽对重离子碰撞中轻强子产生的影响。我们将高效共振衰变框架FastReso推广到具有有限宽度谱函数的共振，随后从强子共振衰变计算π介子、K介子和质子的谱，分别采用介质谱函数和真空谱函数。我们对LHC中心Pb-Pb和Xe-Xe碰撞中测得的粒子谱进行包含衰变馈入的同时 blast-wave 拟合，发现引入热展宽的ρ和ω介子后，低动量下π介子谱增加。有限共振宽度带来的额外π介子产额减小了模型与数据间常见的偏差，但并未完全解决重离子碰撞中的软π介子难题。
英文摘要
The measured hadron yields in heavy-ion collisions are well described by thermal particle production at temperatures close to the QCD pseudo-critical transition. However, if particles are produced in thermal equilibrium, then the in-medium effects, e.g., broadening of their spectral functions, must be taken into account. In this work, we study for the first time the effect of the thermal broadening of the light vector-meson spectral functions on light hadron production in heavy-ion collisions. We generalize the efficient resonance decay framework FastReso to resonances with finite-width spectral functions. We then compute the pion, kaon and proton spectra from the decays of hadron resonances for in-medium and vacuum spectral functions. We perform a simultaneous blast-wave fit with decay feed-down to measured particle spectra in central Pb-Pb and Xe-Xe collisions at the LHC. We find an increase in pion spectra at low momenta, from including thermally broadened $ρ$ and $ω$ mesons. Additional pion yield from finite-resonance widths reduces the commonly observed discrepancy between models and data, but does not completely resolve the soft pion puzzle in heavy-ion collisions.
