TY  - EJOUR
AU  - Horsley, R.
AU  - Nakamura, Y.
AU  - Perlt, H.
AU  - Pleiter, D.
AU  - Rakow, P. E. L.
AU  - Schierholz, G.
AU  - Schiller, A.
AU  - Stüben, H.
AU  - Young, R. D.
AU  - Zanotti, J. M.
TI  - The strange quark contribution to the spin of the nucleon
IS  - arXiv:1901.04792
M1  - PUBDB-2019-00786
M1  - arXiv:1901.04792
M1  - ADP-18-32-T1080
M1  - DESY-18-220
M1  - Liverpool-LTH-1190
PY  - 2019
AB  - Quark line disconnected matrix elements of an operator, such as the axial current, are difficult to compute on the lattice. The standard method uses a stochastic estimator of the operator, which is generally very noisy. We discuss and develop further our alternative approach using the Feynman-Hellmann theorem which involves only evaluating two-point correlation functions. This is applied to computing the contribution of the quark spin to the nucleon and in particular for the strange quark. In this process we also pay particular attention to the development of an SU(3) flavour breaking expansion for singlet operators.
KW  - quark: spin (autogen)
KW  - current: axial (autogen)
KW  - flavor: SU(3) (autogen)
KW  - correlation function (autogen)
KW  - nucleon quark (autogen)
KW  - stochastic (autogen)
KW  - estimator (autogen)
KW  - nucleon (autogen)
KW  - singlet (autogen)
KW  - lattice (autogen)
LB  - PUB:(DE-HGF)25 ; PUB:(DE-HGF)29
DO  - DOI:10.3204/PUBDB-2019-00786
UR  - https://bib-pubdb1.desy.de/record/418882
ER  -