Double parton correlations in mesons within AdS/QCD soft-wall models: a first comparison with lattice data

Abstract

Double parton distribution functions (dPDFs), entering the double parton scattering (DPS) cross section, are unknown fundamental quantities encoding new interesting properties of hadrons. Here, the pion dPDFs are investigated within different holographic QCD quark models in order to access their basic features. Results of the calculations obtained within the AdS/QCD soft-wall approach, have been compared with predictions of lattice QCD evaluations of the pion two-current correlation functions. The present analysis confirms that double parton correlations, affecting dPDFs, are very important and not direct accessible from generalised parton distribution functions and electromagnetic form factors. The comparison between lattice data and quark model calculations unveils the relevance of the contributions of high partonic Fock states in the pion. Nevertheless, by using a complete general procedure, results of lattice QCD have been used, for the first time, to estimate the mean value of the so called $$\sigma _{eff}$$ σ eff , a relevant experimental observable for DPS processes. In addition, the results of the first calculations of the $$\rho $$ ρ meson dPDFs are discussed in order to make predictions.

Double parton distributions in the nucleon from lattice QCD

“…of (2.8) have been found, while the orders of magnitude are consistent with each other [67]. Similar observations have been made in quark model studies [49]. We shall perform analogous investigations for the case of the nucleon in section 5.…”

“…To date, little is known about DPDs, apart from constraints from sum rules that reflect quark number and momentum conservation [33][34][35][36] and from their behavior in the limit of small inter-parton distances [9,13,37]. Beyond this, a considerable number of papers have investigated DPDs in quark models [38][39][40][41][42][43][44][45][46][47][48][49][50].…”

Double parton distributions in the pion from lattice QCD

“…We obtained signals with a good statistical accuracy for almost all contractions and were thus able to study their relative importance. Our results were compared with different models in [13,14].…”

The pion in the graviton soft-wall model: phenomenological applications

“…The pion effective form factor (eff) has been considered lately as a test for models [55]. Such a quantity has been introduced for the first time in the context of double parton scattering (DPS) processes in protonproton collisions and double parton distribution functions (dPDFs) [56].…”