Quark disconnected diagrams in chiral perturbation theory

Michele Della Morte, Andreas Juttner

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

We show how quark-disconnected and quark-connected contributions to hadronic n-point functions can be written as independent correlators for which one can derive expressions in partially quenched chiral effective theory. As an example we apply the idea to the case of the hadronic vacuum polarisation. In particular, we consider the cases of the Nf = 2 theory without and with a partially quenched strange quark and also the Nf = 2 + 1 theory. In the latter two cases a parameter-free prediction for the disconnected contribution at NLO in the effective theory is given. Finally we show how twisted boundary conditions can then be used in lattice QCD to improve the q^2 resolution in the connected contributions even when flavour singlet operators are considered.
OriginalsprogUdefineret/Ukendt
TidsskriftJHEP
ISSN1126-6708
DOI
StatusUdgivet - 20. sep. 2010

Bibliografisk note

19 pages, 4 figures; results unchanged; typos corrected, references added and discussion extended; accepted for publication in JHEP

Emneord

  • hep-lat
  • hep-ph

Citer dette

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Quark disconnected diagrams in chiral perturbation theory. / Morte, Michele Della; Juttner, Andreas.

I: JHEP, 20.09.2010.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Quark disconnected diagrams in chiral perturbation theory

AU - Morte, Michele Della

AU - Juttner, Andreas

N1 - 19 pages, 4 figures; results unchanged; typos corrected, references added and discussion extended; accepted for publication in JHEP

PY - 2010/9/20

Y1 - 2010/9/20

N2 - We show how quark-disconnected and quark-connected contributions to hadronic n-point functions can be written as independent correlators for which one can derive expressions in partially quenched chiral effective theory. As an example we apply the idea to the case of the hadronic vacuum polarisation. In particular, we consider the cases of the Nf = 2 theory without and with a partially quenched strange quark and also the Nf = 2 + 1 theory. In the latter two cases a parameter-free prediction for the disconnected contribution at NLO in the effective theory is given. Finally we show how twisted boundary conditions can then be used in lattice QCD to improve the q^2 resolution in the connected contributions even when flavour singlet operators are considered.

AB - We show how quark-disconnected and quark-connected contributions to hadronic n-point functions can be written as independent correlators for which one can derive expressions in partially quenched chiral effective theory. As an example we apply the idea to the case of the hadronic vacuum polarisation. In particular, we consider the cases of the Nf = 2 theory without and with a partially quenched strange quark and also the Nf = 2 + 1 theory. In the latter two cases a parameter-free prediction for the disconnected contribution at NLO in the effective theory is given. Finally we show how twisted boundary conditions can then be used in lattice QCD to improve the q^2 resolution in the connected contributions even when flavour singlet operators are considered.

KW - hep-lat

KW - hep-ph

U2 - 10.1007/JHEP11(2010)154

DO - 10.1007/JHEP11(2010)154

M3 - Tidsskriftartikel

JO - Journal of High Energy Physics (Online)

JF - Journal of High Energy Physics (Online)

SN - 1126-6708

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