Parton distribution functions of Δ+ on the lattice.

We perform a first calculation for the unpolarized parton distribution function of the Δ+ baryon using lattice QCD simulations within the framework of large momentum effective theory. Two ensembles of Nf = 2 + 1 + 1 twisted mass fermions are utilized with a pion mass of 270 and 360 MeV, respectively. The baryon, which is treated as a stable single-particle state, is boosted with momentum P3 with values {0.42, 0.83, 1.25} GeV, and we utilize momentum smearing to improve the signal. The unpolarized parton distribution function of Δ+ is obtained using a nonperturbative renormalization and a one-loop formula for the matching, with encouraging precision. In particular, we compute the d̅(x) - u̅(x) asymmetry and compare it with the same quantity in the nucleon, in a first attempt towards resolving the physical mechanism responsible for generating such asymmetry. [ABSTRACT FROM AUTHOR]