Determination of the quark condensate from heavy-light current-current correlators in full lattice QCD

Davies, C.T.H. , Hornbostel, K., Komijani, H., Koponen, J., Lepage, G.P., Lytle, A.T. and McNeile, C. (2019) Determination of the quark condensate from heavy-light current-current correlators in full lattice QCD. Physical Review D, 100, 034506. (doi: 10.1103/PhysRevD.100.034506)

Abstract

We derive the operator product expansion whose vacuum expectation value gives the time moments of the pseudoscalar heavy-light current-current correlator up to and including terms in α 2 s multiplying ⟨ ¯ ψ ψ ⟩ / M 3 and terms in α s multiplying ⟨ α s G 2 ⟩ / M 4 , where M is the heavy quark mass. Using lattice QCD results for heavy-strange correlators obtained for a variety of heavy quark masses on gluon field configurations including u , d and s quarks in the sea at three values of the lattice spacing, we are able to show that the contribution of the strange-quark condensate to the time moments is very substantial. We use our lattice QCD time moments and the operator product expansion to determine a value for the condensate, fitting the fourth, sixth, eighth and tenth time moments simultaneously. Our result, ⟨ ¯ s s ⟩ ¯¯¯¯¯¯ MS ( 2     GeV ) = − ( 296 ( 11 )     MeV ) 3 , agrees well with HPQCD’s earlier, more direct, lattice QCD determination [C. McNeile et al. (HPQCD Collaboration), Phys. Rev. D 87, 034503 (2013)]. As well as confirming that the s quark condensate is close in value to the light quark condensate, this demonstrates clearly the consistency of the operator product expansion for fully nonperturbative calculations of matrix elements of short-distance operators in lattice QCD.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lytle, Dr Andrew and McNeile, Dr Craig and Komijani, Hossein and Koponen, Dr Jonna and Davies, Professor Christine
• Authors: Davies, C.T.H., Hornbostel, K., Komijani, H., Koponen, J., Lepage, G.P., Lytle, A.T., and McNeile, C.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review D
• Publisher: American Physical Society
• ISSN: 1550-7998
• ISSN (Online): 1550-2368
• Copyright Holders: Copyright © 2019 The American Physical Society
• First Published: First published in Physical Review D 100:034506
• Publisher Policy: Reproduced under a Creative Commons License