Gluon PDF for the proton using the twisted mass formulation of lattice QCD

Abstract

We present results of the x-dependence of the unpolarized gluon PDF for the proton. We use an $N_f=2+1+1$ ensemble of maximally twisted mass fermions with clover improvement and the Iwasaki improved gluon action. The quark masses are tuned so that the pion mass is 260 MeV. We use a $32^3\times 64$ lattice size with a lattice spacing $a=0.093$ fm giving a spatial extent of 3 fm. We employ the pseudo-distribution approach and obtain the light-cone Ioffe time distribution (ITD) combining data for nucleon momentum boosts up to 1.67 GeV and Wilson line lengths, $z$, up to 0.56 fm. We explore systematic effects such as the dependence on the maximum value of $z$ entering the fits to obtain the gluon PDF.