Unveiling the nucleon tensor charge at Jefferson Lab: A study of the SoLID case

Abstract

Future experiments at the Jefferson Lab 12 GeV upgrade, in particular, the Solenoidal Large Intensity Device (SoLID), aim at a very precise data set in the region where the partonic structure of the nucleon is dominated by the valence quarks. One of the main goals is to constrain the quark transversity distributions. We apply recent theoretical advances of the global QCD extraction of the transversity distributions to study the impact of future experimental data from the SoLID experiments. Especially, we develop a simple strategy based on the Hessian matrix analysis that allows one to estimate the uncertainties of the transversity quark distributions and their tensor charges extracted from SoLID data simulation. We find that the SoLID measurements with the proton and the effective neutron targets can improve the precision of the u-and d-quark transversity distributions up to one order of magnitude in the range 0.05 < x < 0.6.

The Tensor and the Scalar Charges of the Nucleon from Hadron Phenomenology

“…It is in agreement with lattice determinations as well as with the other extractions from hadronic phenomenology [5][6][7][8], though the absolute value is slightly smaller than the lattice's. Due to its nonperturbative nature, the nucleon structure can only be unveiled using complementary methods such as effecive field theories, lattice calculations, models for the nucleon structure, Schwinger-Dyson based techniques and phenomenological extraction of observables from data.…”

“…The results presented here concerning the determination of the scalar and tensor charges through Dihadron Fragmentation Functions can be complemented, in the tensor case, by the Deeply Virtual Meson Production analysis [6] and the Single-hadron SIDIS approach [8].…”

Experimental constraint on quark electric dipole moments

“…The results in Fig. 1 [31,44], the square (blue) points are from lattice QCD calculations [45][46][47][48][49][50], the triangle (magenta) points are from model calculations [34][35][36][37][38][39][40][41][42][43], the filled diamond (black) points are phenomenological extractions from data [51][52][53][54][55], and the hollow diamond (red) points are the projection of JLab-12 GeV SoLID experiments based on the most recent global analysis [52]. The results quoted from the references are evaluated at different scales as explained in the text.…”

“…[52], which includes the TMD evolution effect. At the scale of 4 GeV 2 , the extracted tensor charges for up and down quarks are…”

“…For the proton EDM measurement, a storage ring experiment [64] is proposed apart from the indirect measurements. The new method, which is based on the approach of minimizing the g − 2 precession in the horizontal plane by using a radial electric field, can reach [52]. The strange quark tensor charge g s T ¼ 0.008 AE 0.015 [18] is used for both current and future tensor charge precisions.…”