Quark and Gluon Momentum Fractions in the Pion from N-f=2+1+1 Lattice QCD

We perform the first full decomposition of the pion momentum into its gluon and quark contributions. We employ an ensemble generated by the Extended Twisted Mass Collaboration with N-f = 2 + 1 + 1 Wilson twisted mass clover fermions at maximal twist tuned to reproduce the physical pion mass. We present our results in the (MS) over bar scheme at 2 GeV. We find < x >(u+d) = 0.601(28), < x >(s) = 0.059(13), < x >(c) = 0.019(05), and < x >(g) = 0.52(11) for the separate contributions, respectively, whose sum saturates the momentum sum rule.