Speaker
Description
We perform lattice QCD simulations in order to calculate nucleon four-point functions, which can be used to extract Mellin moments of double parton distributions (DPDs). In this first study, we consider the first DPD Mellin moment of the unpolarized proton. We employ an $n_f = 2+1$ ensemble with pseudoscalar masses of $m_\pi = 355~\mathrm{MeV}$ and $m_K = 441~\mathrm{MeV}$, the results are converted to the $\overline{\mathrm{MS}}$-scheme at the scale $\mu = 2~\mathrm{GeV}$. Our calculation includes all Wick contractions, where for almost all of them a good statistical signal is obtained. We analyze the dependence on the quark flavor and the quark polarization. Furthermore, the validity of frequently used factorization assumptions is investigated.
