We study the deuteron production via the deuteron pion and nucleon catalysis reactions, $\pi pn\leftrightarrow \pi d$ and $Npn\leftrightarrow Nd$, by employing stochastic multiparticle reactions in the hadronic transport approach SMASH for the first time. This is an improvement compared to previous studies, which introduced an artificial fake resonance $d^{\prime }$ to simulate these $3\leftrightarrow 2$ reactions as a chain of $2\leftrightarrow 2$ reactions. The derivation of the stochastic criterion for multiparticle reactions is presented in a comprehensive fashion and its implementation is tested against an analytic expression for the scattering rate and the equilibrating particle yields in box calculations. We then study Au $+$ Au collisions at $\sqrt{s_{NN}}=7.7$ GeV, where we find that multiparticle collisions substantially reduce the time required for deuterons to reach partial chemical equilibrium with nucleons. Subsequently, the final yield of $d$ is practically independent from the number of $d$ at particlization, confirming the results of previous studies. The mean transverse momentum and the integrated elliptic flow as a function of centrality are rather insensitive to the exact realization of the $2\leftrightarrow 3$ reactions.

中文翻译：

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通过随机多粒子反应在相对论重离子碰撞中产生氘

我们通过氘核π介子和核子催化反应研究氘的产生， $\pi 磷n\leftrightarrow \pi d$ 和 $N磷n\leftrightarrow Nd$，通过首次在强子传输方法SMASH 中使用随机多粒子反应。与之前的研究相比，这是一个改进，之前的研究引入了人工假共振$d^{\prime }$ 模拟这些 $3\leftrightarrow 2$ 作为一连串的反应 $2\leftrightarrow 2$反应。多粒子反应的随机准则的推导以全面的方式呈现，并根据散射率和盒计算中的平衡粒子产率的解析表达式对其实施进行了测试。然后我们研究Au$+$ 金碰撞在 $\sqrt{{秒}_{NN}}=7.7$GeV，我们发现多粒子碰撞大大减少了氘核与核子达到部分化学平衡所需的时间。随后，最终产量为$d$ 实际上独立于数量 $d$在粒子化时，证实了以前的研究结果。作为中心性的函数的平均横向动量和积分椭圆流对精确实现相当不敏感$2\leftrightarrow 3$ 反应。