Journal Article

FZJ-2019-05284

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Excited-state effects in nucleon structure on the lattice using hybrid interpolators

Green, J. R. (Corresponding author) ; Engelhardt, M. ; Hasan, N.FZJ* ; Krieg, S.FZJ* ; Meinel, S. ; Negele, J. W. ; Pochinsky, A. V. ; Syritsyn, S. N.

2019
Inst.812068 Melville, NY

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/23233  doi:10.1103/PhysRevD.100.074510

Abstract: It would be very useful to find a way of reducing excited-state effects in lattice QCD calculations of nucleon structure that has a low computational cost. We explore the use of hybrid interpolators, which contain a nontrivial gluonic excitation, in a variational basis together with the standard interpolator with tuned smearing width. Using the clover discretization of the field strength tensor, a calculation using a fixed linear combination of standard and hybrid interpolators can be done using the same number of quark propagators as a standard calculation, making this a cost-effective option. We find that such an interpolator, optimized by solving a generalized eigenvalue problem, reduces excited-state contributions in two-point correlators. However, the effect in three-point correlators, which are needed for computing nucleon matrix elements, is mixed: for some matrix elements such as the tensor charge, excited-state effects are suppressed, whereas for others such as the axial charge, they are enhanced. The results illustrate that the variational method is not guaranteed to reduce the net contribution from excited states except in its asymptotic regime, and suggest that it may be important to use a large basis of interpolators capable of isolating all of the relevant low-lying states.

---

Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)
2. John von Neumann - Institut für Computing (NIC)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)
2. The Proton radius and other aspects of nucleon structure from Lattice QCD (hmz37_20161101) (hmz37_20161101)

Appears in the scientific report 2019

---

Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

---