Speaker
Description
We present lattice QCD results on the unpolarized and helicity GPDs for the proton using a novel method that decomposes the matrix elements into Lorentz-invariant amplitudes. This work is an extension of the proof-of-concept calculation presented in Phys.Rev.D 106 (2022) 11, 114512, which demonstrated that more optimized calculations of GPDs are applicable to any frame, with freedom in the transferred momentum distribution. The numerical calculations presented in this talk use one ensemble of Nf=2+1+1 twisted mass fermions with a clover improvement. The value of the light-quark masses leads to a pion mass of about 260 MeV. Concentrating on the proton and zero skewness, we extract the invariant amplitudes from matrix element calculations in both the symmetric and asymmetric frame and obtain results for the twist-2 light-cone GPDs for unpolarized quarks, 𝐻 and 𝐸, as well as for the chiral-even polarized \tilde{H}.
