Thermal dileptons as fireball thermometer and chronometer
Thermal dileptons as fireball thermometer and chronometer
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DOI：
10.1016/j.physletb.2015.12.065
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发表时间：
2014-11
影响因子：
4.4
通讯作者：
R. Rapp;H. Hees
中科院分区：
文献类型：
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作者：
R. Rapp;H. Hees
来自高能重离子碰撞中产生的热火球的热双轻子辐射提供了对所产生介质性质的独特见解。我们首先展示了强子多体理论对熔化ρ介子的预测，再加上夸克胶子等离子体发射，利用现代晶格QCD状态方程，在SPS和RHIC束能量扫描计划中产生重离子碰撞中双轻子谱的定量描述。我们利用这些结果系统地提取超额产额及其不变的质谱斜率，分别预测火球寿命和（早期）温度的激发函数。因此，我们表明，未来的测量这些量可以产生前所未有的信息基本火球属性。具体来说，我们的预测量化的测量和最大火球温度之间的关系，以及超额产量和总寿命的比例。这些信息可以作为一个“热量”曲线来搜索一阶QCD相变，并检测可能与临界现象有关的非单调寿命变化。
Thermal dilepton radiation from the hot fireballs created in high-energy heavy-ion collisions provides unique insights into the properties of the produced medium. We first show how the predictions of hadronic many-body theory for a meltingρmeson, coupled with quark–gluon plasma emission utilizing a modern lattice-QCD based equation of state, yield a quantitative description of dilepton spectra in heavy-ion collisions at the SPS and the RHIC beam energy scan program. We utilize these results to systematically extract the excess yields and their invariant-mass spectral slopes to predict the excitation function of fireball lifetimes and (early) temperatures, respectively. We thereby demonstrate that future measurements of these quantities can yield unprecedented information on basic fireball properties. Specifically, our predictions quantify the relation between the measured and maximal fireball temperature, and the proportionality of excess yield and total lifetime. This information can serve as a “caloric” curve to search for a first-order QCD phase transition, and to detect non-monotonous lifetime variations possibly related to critical phenomena.