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FZJ-2017-00064

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Applications of the Feynman-Hellmann theorem in hadron structure

Chambers, A. ; Horsley, R. ; Nakamura, Y. ; Perlt, H. ; Pleiter, D.FZJ* ; Rakow, P. E. L. ; Schierholz, G. ; Schiller, A. ; Stuben, H. ; Young, R. D. ; Zanotti, J.

2015
SISSA Trieste

Please use a persistent id in citations: http://hdl.handle.net/2128/13378

Report No.: PoS(LATTICE 2015)125

Abstract: The Feynman-Hellmann (FH) relation offers an alternative way of accessing hadronic matrix elements through artificial modifications to the QCD Lagrangian. In particular, a FH-motivated method provides a new approach to calculations of disconnected contributions to matrix elements and high-momentum nucleon and pion form factors. Here we present results for the total nucleon axial charge, including a statistically significant non-negative total disconnected quark contribution of around 􀀀5% at an unphysically heavy pion mass. Extending the FH relation to finite-momentum transfers, we also present calculations of the pion and nucleon electromagnetic form factors up to momentum transfers of around 7–8 GeV2. Results for the nucleon are not able to confirm the existence of a sign change for the ratio GE/GM, but suggest that future calculations at lighter pion masses will provide fascinating insight into this behaviour at large momentum transfers.

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Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)

Appears in the scientific report 2016

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