Chiral extrapolation of matrix elements of BSM kaon operators

Jon A. Bailey, Hyung Jin Kim, Weonjong Lee, Stephen R. Sharpe

Research output: Contribution to journalConference articlepeer-review

Abstract

Models of new physics induce K0 -K0 mixing through operators having Dirac structures other than the "left-left" form of the Standard Model. To carry out the chiral-continuum extrapolation of results from numerical simulations, one needs to know the quark mass and lattice spacing dependence of the corresponding B-parameters in the partially quenched theory at least at nextto- leading order. For simulations using staggered fermions (such as that we are doing with HYPsmeared valence fermions on theMILC asqtad lattices) onemust determine this dependence using staggered chiral perturbation theory (SChPT).We have calculated the required dependence in both SU(3) and SU(2) SChPT, working at next-to-leading order, and we give here an overview of the methodology and results. The SU(3) SChPT result turns out to be much simpler than that for the Standard Model BK operator, due to the absence of chiral suppression for the new operators. The SU(2) SChPT result turns out to be closely related to that for BK: the chiral logarithms are identical, up to an operator-dependent sign. Our results are also useful for fermions with chiral symmetry as they provide, in the continuum limit, the partially quenched generalization of existing continuum results.

Original languageEnglish
Article number093
JournalProceedings of Science
VolumePart F130497
Publication statusPublished - 2012
Event30th International Symposium on Lattice Field Theory, Lattice 2012 - Cairns, Australia
Duration: 2012 Jun 242012 Jun 29

All Science Journal Classification (ASJC) codes

  • General

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