The Electron-Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities of up to $1.0\times {10}^{34}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$ in the center-of-mass energy range of 20–140 GeV. To achieve such high luminosity, the EIC will employ small and flat beams at the interaction point. In the hadron storage ring of the EIC, the ratio of horizontal to vertical emittances is approximately $11:1$. In contrast, in previous or existing hadron colliders, the horizontal and vertical emittances are typically similar or closely matched. At the Relativistic Heavy Ion Collider (RHIC), we experimentally demonstrated a large transverse emittance ratio of $11:1$ with gold ion beams at a particle energy of 100 GeV per nucleon, thanks to stochastic cooling and fine decoupling. Furthermore, we demonstrated collisions with flat beams, featuring a transverse beam size ratio of $3:1$ for the first time at the RHIC.

中文翻译：

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电子离子对撞机相对论性重离子对撞机大横向发射比11∶1的实验演示

将在布鲁克海文国家实验室建造的电子离子对撞机（EIC）将使偏振高能电子束与强子束碰撞，实现高达$1.0\times {10}^{34}{\mathrm{厘米}}^{-2}{\mathrm{s}}^{-1}$质心能量范围为 20–140 GeV。为了实现如此高的亮度，EIC 将在相互作用点采用小且平坦的光束。在 EIC 的强子存储环中，水平发射度与垂直发射度之比约为$11:1$。相反，在先前或现有的强子对撞机中，水平和垂直发射度通常相似或紧密匹配。在相对论重离子对撞机（RHIC）上，我们通过实验证明了大横向发射率$11:1$由于随机冷却和精细解耦，金离子束的粒子能量为每个核子 100 GeV。此外，我们还演示了与平板梁的碰撞，其横梁尺寸比为$3:1$首次参加 RHIC。