Parton Distribution Functions from a Light Front Hamiltonian and QCD Evolution for Light Mesons

Abstract

We obtain the pion and the kaon parton distribution functions from the eigenstates of a light front effective Hamiltonian in the constituent quark-antiquark representation suitable for low-momentum scale applications. By taking these scales as the only free parameters, the valence quark distribution functions of the pion, after QCD evolution, are consistent with the data from the FNAL-E615 experiment. The ratio of the up quark distribution of the kaon to that of the pion also agrees with the CERN-NA3 experiment. Supplemented by known parton distribution functions for the nucleons, we further obtain the cross section consistent with experimental data for the π − nucleus → µ + µ − X Drell-Yan process. * jiangshanlan@impcas.ac.cn

Pion and kaon parton distribution functions from basis light front quantization and QCD evolution

“…It has been used to investigate a variety of systems and reactions [5][6][7][8][9][10][11] . Recently, the BLFQ approach using a Hamiltonian that includes the color singlet Nambu-Jona-Lasinio (NJL) interaction to account for the chiral dynamics has been applied to light mesons [12][13][14] . In this work, we present results for the parton distribution functions (PDFs) of the light mesons.…”

Pion valence structure from Ioffe-time parton pseudodistribution functions

“…These effects are significantly smaller than what an O(z 2 Λ 2 QCD ) estimation would have provided. The value < x 1 >= 0.2541(26) denoted by the green band in a latt 4…”

Pion-nucleus induced Drell-Yan cross section in models inspired by light-front holography

“…We observe that both the models agree with the theoretical results in Refs. [3,6,8,12,21,22,36,37]. However, the Model-II shows a better agreement compared to the Model-I for the higher moments.…”

“…(10) and (14) to the relevant experimental scale µ 2 = 16 GeV 2 using the higher order perturbative parton evolution toolkit (HOPPET) to solve the NNLO DGLAP equations [71]. While applying the DGLAP equations numerically, we impose the condition that the running coupling α s (µ 2 ) saturates in the infrared at a cutoff value of max α s = 1 [36,72]. We adopt the initial scale µ 2 0I = 0.236 ± 0.024 GeV 2 for the Model-I, which we determine by requiring the results after QCD evolution to fit the reanalysis of the FNAL-E-0615 data for the pion PDF [9,73].…”

“…The pion PDF has also been the subject of detailed analyses in lattice QCD [6,22,23,24,25,26,27]. It has also been investigated in phenomenological models such as the Nambu-Jona-Lasinio (NJL) model [28], the constituent quark model [29,30], the chiral quark model [31], anti-de Sitter (AdS)/QCD models [32,33,34,35], a basis light-front quantization approach [36,37] etc..…”