The polarized nucleon structure function in the nonsinglet case is investigated here by a new insight rather than conventional perturbative QCD (pQCD). For this purpose we note that the solution of the evolution equations in moment space involves noninteger powers of the coupling constant. Therefore it is possible to employ a new approach which is called fractional analytical perturbation theory Consequently, it is possible to remove the Landau singularities of the renormalized coupling, i.e., at the scales $Q \sim Λ$, using this approach. This provides an opportunity to continue the desired calculations toward small values of energy scales even less than the $Λ$ scale. To modify the analytical perturbation theory, a newer approach is introduced, called 2$δ$anQCD, in which the spectral function of the holomorphic coupling is parameterized in the low-energy region by two delta functions. This model gives us more reliable results for the considered QCD observables, even in the deep infrared region. We calculate the nonsinglet part of the polarized nucleon structure function, using the 2$δ$anQCD model, and compare it with the result from the underlying pQCD where both are in a new defined scheme, called the Lambert scheme. For this purpose we employ the anQCD package in the \textit{Mathematica} environment to establish the analytic (holomorphic) coupling constant. The results at various energy scales are also compared with the available experimental data, and it turns out that there is a good consistency between them. The results show that the obtained nucleon structure function at small energy scales has smoother behavior when using the 2$δ$anQCD model than the underlying pQCD. In fact the coupling constant in analytic QCD behaves moderately and it makes the result approach the available data in a better way.
Universal modified function in conjunction with the short range correlation effect to extract the nuclear $xF_3^A$ structure function
Yazd University(亚兹德大学);Malayer University(马拉耶尔大学);Institute for Research in Fundamental Sciences (IPM)(基础科学研究院(IPM));Shahid Bahonar University of Kerman(克尔曼沙希德巴纳卡尔大学)
Accessing nucleon transversity with one-point energy correlators
Fudan University(复旦大学);University of California, Los Angeles(加州大学洛杉矶分校);Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles(加州大学洛杉矶分校马尼·L·巴乌米克理论物理研究所);Center for Frontiers in Nuclear Science, Stony Brook University(纽约州立大学石溪分校核科学前沿中心);Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University(复旦大学核物理与离子束应用教育部重点实验室);Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University(国家自然科学基金委与复旦大学上海理论核物理研究中心);Center for High Energy Physics, Peking University(北京大学高能物理中心)