Speaker
Description
Double parton scattering in p+p and p+A collisions is described by double parton distribution functions (dPDFs), a joint distribution over two partons. dPDFs differ from a product of single-parton distribution functions (PDF) since they encode parton correlations. We compute the double quark density matrix and dPDF from a simple three-quark model proton light-cone wave function. We then employ methods from quantum information theory to identify the presence of quantum (entanglement) vs. classical correlations between valence quarks in this model. Quantum correlations are found to be responsible for a suppression of the dPDF when $x_1 \ll x_2$. Finally, we show that the perturbative emission of a soft gluon from any of the valence quarks does not affect their reduced density matrix.
