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arXiv 2002.02597nucl-ex
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用$F_2^{n}$中子结构函数检验EMC效应

Examining the EMC Effect using the $F_2^{n}$ neutron structure function

H. Szumila-Vance, C. Keppel, S. Escalante, N. Kalantarians

摘要:

在深度非弹性散射(通常称为“EMC效应”)中测量的核靶结构函数与氘结构函数之比的持续神秘偏离已经成为研究价态下核介质对自由核子结构的修改的典型观察结果。自由质子的结构函数从跨越几十年的大量实验中众所周知。然而,自由中子结构函数仍然难以获得。最近,它已被提取在一个系统的研究中的全球数据内的部分子分布函数提取框架,并可从CTEQ-Jefferson实验室(CJ)合作。在这里,我们利用后者介绍了一种新的方法来研究EMC效应的原子核中重新检查现有的数据,根据介质修改的自由中子和质子的结构功能独立的幅度。从世界数据中提取自由中子,可以检查氘的核效应及其对我们解释EMC效应的贡献。在这项研究中,我们观察到的比率的自由中子和质子的结构函数的总和有一些$x_{B}$和$Q^{2}$的依赖性,影响的EMC效应的大小,通常观察到。具体地,当利用来自不同的$x_{B}$和$Q^{2}$值的数据时,获得不同的EMC斜率。虽然EMC和短程相关效应之间存在线性相关,但当去除氘核效应时,斜率被修改。

英文摘要:

The persistently mysterious deviations from unity of the ratio of nuclear target structure functions to those of deuterium as measured in deep inelastic scattering (often termed the "EMC Effect") have become the canonical observable for studies of nuclear medium modifications to free nucleon structure in the valence regime. The structure function of the free proton is well known from numerous experiments spanning decades. The free neutron structure function, however, has remained difficult to access. Recently it has been extracted in a systematic study of the global data within a parton distribution function extraction framework and is available from the CTEQ-Jefferson Lab (CJ) Collaboration. Here, we leverage the latter to introduce a new method to study the EMC Effect in nuclei by re-examining existing data in light of the the magnitude of the medium modifications to the free neutron and proton structure functions independently. From the extraction of the free neutron from world data, it is possible to examine the nuclear effects in deuterium and their contribution to our interpretation of the EMC Effect. In this study, we observe that the ratio of the deuteron to the sum of the free neutron and proton structure functions has some $x_{B}$ and $Q^{2}$ dependencies that impact the magnitude of the EMC Effect as typically observed. Specifically, different EMC slopes are obtained when data from different $x_{B}$ and $Q^{2}$ values are utilized. While a linear correlation persists between the EMC and short range correlation effects, the slope is modified when deuteron nuclear effects are removed.

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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