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arXiv · 1501.07639

Precision calculations of nucleon charges $g_A$, $g_S$, $g_T$

Rajan Gupta·Tanmoy Bhattacharya·Anosh Joseph·Huey-Wen Lin·Boram Yoon
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Abstract

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 ($M_π\approx 310,\ 220$ 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.

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Rajan Gupta, Tanmoy Bhattacharya, Anosh Joseph, Huey-Wen Lin, Boram Yoon. 2015-01-30. Precision calculations of nucleon charges $g_A$, $g_S$, $g_T$. https://arxiv.org/abs/1501.07639

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