Gravitational form factors of the pion from lattice QCD

The two gravitational form factors of the pion, A pi(t) and D pi(t), are computed as functions of the momentum transfer squared t in the kinematic region 0 <=-t<2 GeV2 on a lattice QCD ensemble with quark masses corresponding to a close-to-physical pion mass m pi approximate to 170 MeV and Nf=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 mu=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 pi(0).