论文标题
在光子铅碰撞中具有较大动量转移的独家二重数中的方位角相关性
Azimuthal correlations within exclusive dijets with large momentum transfer in photon-lead collisions
论文作者
论文摘要
核子的结构是多维的，取决于组成部分的横向动量，空间几何形状和极化。可以使用在超疗养重离子碰撞中产生的高能光子来研究这种结构。出现了在大动量转移下，在光子铅相互作用中，仅产生两个喷气式的事件的方位角角相关性的第一个测量，这一过程被认为对基本的核胶状极化很敏感。本研究使用$ \ sqrt {s_ \ mathrm {nn}} $ = 5.02 TEV的超递铅铅碰撞碰撞的数据样本，对应于0.38 nb $^{ - 1} $的集成光度，并通过LHC的CMS实验收集。发现两个射流动量的总和与差异之间的相关性的第二个谐波被发现是正的，并且随着二杰动量的增加而上升。一个成功地描述HERA实验的质子散射数据的良好调整模型未能描述观察到的相关性，这表明存在Gluon极化效应。
The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV, corresponding to an integrated luminosity of 0.38 nb$^{-1}$, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet momenta is found to be positive, and rising, as the dijet momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.
