An analysis of parton distribution functions of the pion and the kaon with the maximum entropy input

Abstract

We present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton–parton recombination corrections and the valence input of uniform distribution which maximizes the information entropy. At our input scale $$Q_0^2$$ Q 0 2 , there are no sea quark and gluon distributions. All the sea quarks and gluons of the pion and the kaon are completely generated from the parton splitting processes. The mass-dependent parton splitting kernel is applied for the strange quark distribution in the kaon. The obtained valence quark and sea quark distributions at high $$Q^{2}$$ Q 2 ($$Q^2>5$$ Q 2 > 5 GeV$$^2$$ 2 ) are compatible with the existed experimental measurements. Furthermore, the asymptotic behaviours of parton distribution functions at small and large x have been studied for both the pion and the kaon. Lastly, the first three moments of parton distributions at high $$Q^{2}$$ Q 2 scale are calculated, which are consistent with other theoretical predictions.

Emergence of pion parton distributions

“…( 15). This remains true at next-to-leading-order [65][66][67]. On the other hand, inclusion of soft-gluon resummation in the hard-scattering kernel produces [64] the teal squares in Fig.…”

“…Nevertheless, more than forty years after the first experiment [37] to deliver data relating to u π (x 1), the empirical status remains confused because, amongst the methods used to fit extant data, e.g., Refs. [64][65][66][67], some return a u π form that violates Eq. (15).…”

Tackling the kaon structure function at EicC

“…Since there is almost no experimental data on kaon structure, there is no global analysis on the kaon PDFs. Therefore in this work, we use the kaon PDFs provided by an model-dependent analysis of the NA3 data only [41]. This analysis is based on the dynamical parton distribution model with only valence quark distributions at Q 2 0 , where the sea quark and gluon distributions are completely produced from the QCD fluctuations.…”

“…As there is almost no experimental data on kaon structure, there is also no global analysis of the kaon PDFs. Nevertheless in our previous work [41,42], we have determined the kaon PDFs from a model-dependent analysis of the eight data points of NA3 experiment [30], based on the dynamical parton distribution model. According to the JAM analysis of pion PDFs [43], the addition of the leading neutron tagged DIS data of H1 [34] and ZEUS [35] significantly reduce the uncertainties of sea quark and gluon distributions.…”

Concerning pion parton distributions

“…Section 2 explains QCD constraints on the behaviour of the pion valence-quark DF at large values of the lightfront longitudinal momentum fraction, x; and Secs. 3, 4 review aspects of existing experiments [29][30][31][32] and associated phenomenological fits [33][34][35][36] which relate to the determination of this behaviour. Section 5 presents a novel perspective on the data in Ref.…”