We investigate the collision energy dependence of deuteron and antideuteron emission in the RHIC-BES low- to mid-energy range \(\sqrt{s_{NN}}\) = 4.6–200 GeV where the formation rate of antinuclei compared to nuclei is strongly suppressed. In the coalescence picture, this can be understood as bulk emission for nuclei in contrast to surface emission for antinuclei. By comparison with experimental data on the coalescence parameter \(B_2\), we are able to extract the respective source geometries. This interpretation is further supported by results from the UrQMD transport model, and establishes the following picture: At low energies, nucleons freeze out over the total fireball volume, while antinucleons are annihilated inside the nucleon-rich fireball and can only freeze out on its surface. Towards higher energies, this annihilation effect becomes less significant because of the enhanced meson production in the reaction. Thus, the nucleon and antinucleon freeze-out distributions become similar with increasing energy.

我们在RHIC-BES低能量至中能量范围\（\ sqrt {s_ {NN}} \） = 4.6–200 GeV中研究氘核和氘核的碰撞能量依赖性，其中反核的形成率与核相比强烈压制。在合并图中，这可以理解为原子核的大量发射与反核的表面发射相反。通过与合并参数\（B_2 \）的实验数据进行比较，我们能够提取相应的源几何。UrQMD传输模型的结果进一步支持了这种解释，并建立了以下图景：在低能量时，核子在整个火球体积中冻结，而反核子在富含核子的火球内部inside灭，并且只能在其表面冻结。对于更高的能量，由于反应中介子产生的增加，这种。灭作用变得不那么重要。因此，随着能量增加，核子和反核子的冻结分布变得相似。