TY - CONF AU - Horsley, Roger AU - Nakamura, Y. AU - Perlt, H. AU - Pleiter, D. AU - Rakow, P. E. L. AU - Schierholz, Gerrit AU - Schiller, A. AU - Stuben, H. AU - Young, R. D. AU - Zanotti, J. M. TI - The strange quark contribution to the spin of the nucleon JO - Proceedings of Science / International School for Advanced Studies VL - (LATTICE2018) IS - arXiv:1901.04792 SN - 1824-8039 CY - Trieste PB - SISSA M1 - PUBDB-2019-02503 M1 - arXiv:1901.04792 M1 - ADP-18-32-T1080 M1 - DESY-18-220 M1 - Liverpool-LTH-1190 SP - 119 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. T2 - The 36th Annual International Symposium on Lattice Field Theory CY - 22 Jul 2018 - 28 Jul 2018, Michigan State University (East Lansing) Y2 - 22 Jul 2018 - 28 Jul 2018 M2 - Michigan State University, East Lansing LB - PUB:(DE-HGF)16 ; PUB:(DE-HGF)29 ; PUB:(DE-HGF)8 DO - DOI:10.22323/1.334.0119 UR - https://bib-pubdb1.desy.de/record/423245 ER -