Excited-state effects in nucleon structure on the lattice using hybrid interpolators
AuthorGreen, Jeremy R.
Negele, John W.
Pochinsky, Andrew V.
Syritsyn, Sergey N.
AffiliationUniv Arizona, Dept Phys
MetadataShow full item record
PublisherAMER PHYSICAL SOC
CitationGreen, J. R., Engelhardt, M., Hasan, N., Krieg, S., Meinel, S., Negele, J. W., ... & Syritsyn, S. N. (2019). Excited-state effects in nucleon structure on the lattice using hybrid interpolators. Physical Review D, 100(7), 074510.
JournalPHYSICAL REVIEW D
RightsPublished by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
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AbstractIt 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.
VersionFinal published version
SponsorsU.S. Department of Energy (DOE), Office of Science, Office of High Energy PhysicsUnited States Department of Energy (DOE) [DE-SC0009913.]; RIKEN BNL Research Center; Office of Nuclear Physics of the U.S. DOE [DE-FG02-96ER40965, DE-SC-0011090, DE-SC0018121]; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [SFB-TRR 55]; University of Arizona; Stony Brook University