Abstract
We present our recent high precision calculations [1, 2] of the first moment of nucleon isovector polarized, unpolarized and transversity distributions, i.e., momentum fraction, helicity and transversity moment, respectively. We use the standard method for the calculation of these moments (via matrix elements of twist two operators), and carry out a detailed analysis of the sources of systematic uncertainty, in particular of excited state contributions. Our calculations have been performed using two different lattice setups (Clover-on-HISQ and Clover-on-Clover), each with several ensembles. They give consistent results that are in agreement with global fit analyses.
| Original language | English |
|---|---|
| Article number | 513 |
| Journal | Proceedings of Science |
| Volume | 396 |
| State | Published - Jul 8 2022 |
| Event | 38th International Symposium on Lattice Field Theory, LATTICE 2021 - Virtual, Online, United States Duration: Jul 26 2021 → Jul 30 2021 |
Funding
We thank the MILC Collaboration for sharing the HISQ ensembles. The calculations used the Chroma software suite [15]. We gratefully acknowledge computing resources provided by NERSC, OLCF at Oak Ridge, USQCD and LANL Institutional Computing. Support for this work was provided the U.S. DOE Office of Science, HEP and NP, the NSF, and by the LANL LDRD program. The work of SM and HL are partially supported by the US National Science Foundation under grant PHY 1653405 “CAREER: Constraining Parton Distribution Functions for New-Physics Searches” and by the Research Corporation for Science Advancement through the Cottrell Scholar Award.
| Funders | Funder number |
|---|---|
| LANL LDRD | |
| National Science Foundation | PHY 1653405 |
| Research Corporation for Science Advancement | |
| Office of Science |