Gravitational form factors of the pion from lattice QCD

The two gravitational form factors of the pion, A^ (t) and D^ (t), are computed as functions of the momentum transfer squared t in the kinematic region 0-t<2 GeV^2 on a lattice QCD ensemble with quark masses corresponding to a close-to-physical pion mass m_170 MeV and N₅=2+1 quark flavors. The flavor decomposition of these form factors into gluon, up/down light-quark, and strange-quark contributions is presented in the MS scheme at energy scale =2 GeV, with renormalization factors computed nonperturbatively via the RI-MOM scheme. Using monopole and z-expansion fits to the gravitational form factors, we obtain estimates for the pion momentum fraction and D term that are consistent with the momentum fraction sum rule and the next-to-leading order chiral perturbation theory prediction for D^ (0).