  We present a detailed analysis of statistical and systematic errors in the
calculation of matrix elements of iso-vector scalar, axial and tensor charges
between a neutron and a proton state. These analyses are being done on
dynamical $N_f=2+1+1$ HISQ configurations generated by the MILC Collaboration
using valence clover fermions. Using ensembles at three values of the lattice
spacing ($a=0.12,\ 0.09,$ and $0.06$ fm) and three values of the quark mass
($M_\pi \approx 310,\ 220$ and $130$ MeV) we find that the estimates of the
tensor charge are stable and it can be extracted with $5\%$ precision with
O(10,000) measurements. We also find that higher statistics are needed to
resolve the various uncertainties in the calculation of $g_A$ and improve the
signal in $g_S$, which with present data has large errors. A brief status
report on the mixing and renormalization of novel operators contributing to
nEDM is also given.

High Energy Physics - Lattice