Moments of generalized parton distributions and quark angular momentum of the nucleon

Abstract

The internal structure of hadrons is important for a variety of topics, including the hadron form factors, proton spin and spin asymmetry in polarized proton scattering. For a systematic study generalized parton distributions (GPDs) encode important information on hadron structure in the entire impact parameter space. We report on a computation of nucleon GPDs based on simulations with two dynamical non-perturbatively improved Wilson quarks with pion masses down to 350MeV. We present results for the total angular momentum of quarks with chiral extrapolation based on covariant baryon chiral perturbation theory.

Nucleon’s energy–momentum tensor form factors in light-cone QCD

“…Approaches M q 2 (0) J q (0) d q 1 (0)c q (Q 2 ) Lattice QCD [9] 0.89 ± 0.08 0.45 ± 0.04 --Lattice QCD [10] 0.76 ± 0.14 0.38 ± 0.07 --Lattice QCD [11] 0.73 ± 0.07 0.43 ± 0.07 -1.33 ± 0.06 -Lattice QCD [12] 0.73 ± 0.06 0.32 ± 0.03 -2.15 ± 0.10 -Lattice QCD [13] 0.64 ± 0.03 0.34 ± 0.02 -2.78 ± 0.36 -Lattice QCD [14] 0.76 ± 0.01 0.30 ± 0.01 --Lattice QCD [15] 0.80 ± 0.03 0.40 ± 0.02 --Lattice QCD [16] 0.79 ± 0.06 0.43 ± 0.05 --χPT [22] 0.70 ± 0.02 0.32 ± 0.06 -2.38 ± 0.08 -IFF [23] 0.72 0. with Λ = 0.2 GeV. Table III displays a comparison of our results at Q 2 = 0 with those of the various theoretical models, Lattice QCD and existing experimental data for d q 1 (0) at re-normalization scale µ 2 = 1 GeV 2 .…”

“…The explicit forms of the various F functions that come into view in Eqs. (14) to (17) are presented in Appendix B with respect to the distribution amplitudes of the nucleon. For the sake of brevity, in Appendix B, only the results for the M q 2 (Q 2 ) form factor are presented, explicitly.…”

“…The EMTFFs of the nucleon have been investigated in the framework of Lattice QCD [9][10][11][12][13][14][15][16], chiral perturbation theory (χPT) [17][18][19][20][21][22], instant and front form (IFF) [23], Skyrme model [24,25], chiral quark soliton model (χQSM) [7,[26][27][28][29][30][31][32][33][34][35], light-cone QCD sum rules at leading order(LCSR-LO) [36], dispersion relation (DR) [37] and instanton picture (IP) [38]. In Ref.…”

“…In Ref. [14], Brommel et al reported on a calculation of nucleon's GPDs based on simulations with two dynamical non-perturbatively improved Wilson quarks with pion masses down to 350 MeV. They found J q = 0.226 ± 0.013 and M q 2 = 0.572 ± 0.012 at re-normalization scale of µ 2 = 4 GeV 2 .…”

Gravitational transition form factors of N(1535)→N

“…Hence, the investigation of these FFs receives significant interest for comprehension of the internal structure of the nucleon. The GFFs of the nucleon have been examined within different theoretical models such as, chiral quark soliton model (χQSM) [1][2][3][4][5][6][7][8][9][10][11], lattice QCD [12][13][14][15][16][17][18][19], light-cone QCD sum rules (LCSR) [20,21], Skyrme model [22,23], chiral perturbation theory (χPT) [24][25][26][27][28][29], Bag model [30], and, instant and front form (IFF) [31]. Interested readers can find more details about these studies in a recent review [32].…”