Determination of unpolarized pion fragmentation functions using semi-inclusive deep-inelastic-scattering data
Determination of unpolarized pion fragmentation functions using semi-inclusive deep-inelastic-scattering data
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DOI：
10.1103/physrevd.104.034007
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发表时间：
2021-05
影响因子：
5
通讯作者：
Rabah Abdul Khalek;V. Bertone;E. Nocera
中科院分区：
文献类型：
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作者：
Rabah Abdul Khalek;V. Bertone;E. Nocera
我们提出了MAPFF 1.0，一个从一组单包e^+e^-$湮灭和轻子-核子半包深非弹性散射（SIDIS）数据中确定非极化带电π介子碎裂函数（FF）的方法。FF参数化的神经网络（NN）和拟合数据利用知识的解析导数的NN本身w.r.t.自由参数。通过适当考虑实验不确定性的所有来源，包括部分子分布函数的Monte Carlo抽样方法确定FF上的不确定性。在微扰QCD中，对相关观测量以及演化效应的理论预测被计算到了次领先阶（NLO）的精度。我们利用味道的灵敏度的SIDIS测量提供的爱马仕和COMPASS实验，以确定一个最小的偏差设置7个独立的FF组合。此外，我们讨论了低虚拟度的SIDIS数据的拟合质量，正如预期的那样，低Q^2 $ SIDIS测量通常更难在NLO精确的微扰框架内描述。
We present MAPFF1.0, a determination of unpolarised charged-pion fragmentation functions (FFs) from a set of single-inclusive $e^+e^-$ annihilation and lepton-nucleon semi-inclusive deep-inelastic-scattering (SIDIS) data. FFs are parametrised in terms of a neural network (NN) and fitted to data exploiting the knowledge of the analytic derivative of the NN itself w.r.t. its free parameters. Uncertainties on the FFs are determined by means of the Monte Carlo sampling method properly accounting for all sources of experimental uncertainties, including that of parton distribution functions. Theoretical predictions for the relevant observables, as well as evolution effects, are computed to next-to-leading order (NLO) accuracy in perturbative QCD. We exploit the flavour sensitivity of the SIDIS measurements delivered by the HERMES and COMPASS experiments to determine a minimally-biased set of seven independent FF combinations. Moreover, we discuss the quality of the fit to the SIDIS data with low virtuality $Q^2$ showing that, as expected, low-$Q^2$ SIDIS measurements are generally harder to describe within a NLO-accurate perturbative framework.