arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2002.01201nucl-th
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具有$ϕ$介子产生的AMPT模型的输入参数约束

Constraining input parameters of AMPT model with $ϕ$ meson production

Katyayni Tiwari, Md. Nasim

摘要:

多相输运模型(AMPT)已被广泛用于理解实验观察背后的物理。与其他模型一样,AMPT模型的结果取决于初始参数。因此,在使用模型之前,需要选择合适的初始参数。在AMPT模型中,Lund弦碎裂函数被用来产生夸克-反夸克对。Lund弦碎裂参数决定了核-核碰撞中产生的粒子的产额和横动量($p_{T}$)谱。通过对实验测量的带电粒子产额和$p_{T}$谱的拟合,确定了Lund弦碎裂参数的值。在本文中,我们已经表明,奇怪的夸克携带强子,如$ϕ$介子的产额,是更敏感的隆德弦碎裂参数相比,非奇怪的介子。利用RHIC上测量的$ϕ$介子谱,我们得到了$\sqrt{s_{\mathrm {NN}}}$ = 11.5,39和200 GeV的Au+Au碰撞的新的Lund参数。我们发现,使用同一组参数,我们可以解释$\sqrt{s_{\mathrm {NN}}}$ = 39和200 GeV时的$ϕ$ -介子产额,然而,对于$\sqrt{s_{\mathrm {NN}}}$ = 11.5 GeV,我们需要一组不同的参数。这表明,在低能量,$\sqrt{s_{\mathrm {NN}}}$ = 11.5 GeV,粒子产生的基本机制是不同的顶部RHIC能量相比。我们还预测了在$\sqrt{s_{\mathrm {NN}}}$ = 196 GeV的U+U碰撞中,由STAR实验测量的$π$和$ϕ$介子的不变产额随$p_{T}$的变化.

英文摘要:

A Multi-Phase Transport Model (AMPT) has been extensively used to understand the physics behind the experimental observation. Like other models, the outcome of the AMPT model depends on the initial parameters. Therefore, one needs to choose suitable initial parameters before using the model. Lund string fragmentation function has been used to create quark-antiquarks pairs in the AMPT model. The Lund string fragmentation parameters determine the yields and transverse momentum ($p_{T}$) spectra of particles produced in nucleus-nucleus collisions. The values of Lund string fragmentation parameters were determined by fitting the charged particle yield and $p_{T}$ spectra measured in the experiment. In this paper, we have shown the yield of strange quarks carrying hadrons, e.g. $ϕ$ mesons, are more sensitive to Lund string fragmentation parameters compared to non-strange pions. Using $ϕ$ meson spectra measured at RHIC, we have obtained new sets of Lund parameters for Au+Au collisions at $\sqrt{s_{\mathrm {NN}}}$ = 11.5, 39, and 200 GeV. We have found that using the same set of parameters, we can explain $ϕ$-meson yield at $\sqrt{s_{\mathrm {NN}}}$ = 39 and 200 GeV, however, we need a different set of parameters for $\sqrt{s_{\mathrm {NN}}}$ = 11.5 GeV. This suggests that at low energy, $\sqrt{s_{\mathrm {NN}}}$ = 11.5 GeV, the underlying mechanism for particle production is different compared to top RHIC energies. We have also predicted invariant yield of $π$ and $ϕ$ mesons as a function of $p_{T}$ in U+U collisions at $\sqrt{s_{\mathrm {NN}}}$ = 196 GeV to be measured by STAR experiment.

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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