Neutral kaon mixing beyond the Standard Model with nf = 2 + 1 chiral fermions. Part 1: bare matrix elements and physical results

Garron, N., Hudspith, R. J. and Lytle, A. T. (2016) Neutral kaon mixing beyond the Standard Model with nf = 2 + 1 chiral fermions. Part 1: bare matrix elements and physical results. Journal of High Energy Physics, 2016(11), 1. (doi: 10.1007/JHEP11(2016)001)

Abstract

We compute the hadronic matrix elements of the four-quark operators relevant for K0 − K¯ 0 mixing beyond the Standard Model. Our results are from lattice QCD simulations with n f = 2 + 1 flavours of domain-wall fermion, which exhibit continuum-like chiral-flavour symmetry. The simulations are performed at two different values of the lattice spacing ( a ∼ 0 .08 and a ∼ 0 .11 fm) and with lightest unitary pion mass ∼ 300 MeV. For the first time, the full set of relevant four-quark operators is renormalised non-perturbatively through RI-SMOM schemes; a detailed description of the renormalisation procedure is presented in a companion paper. We argue that the intermediate renormalisation scheme is responsible for the discrepancies found by different collaborations. We also study different normalisations and determine the matrix elements of the relevant four-quark operators with a precision of ∼ 5% or better.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lytle, Dr Andrew
• Authors: Garron, N., Hudspith, R. J., and Lytle, A. T.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of High Energy Physics
• Publisher: Springer
• ISSN: 1126-6708
• ISSN (Online): 1029-8479
• Published Online: 02 November 2016
• Copyright Holders: Copyright © 2016 The Authors
• First Published: First published in Journal of High Energy Physics 2016(11):1
• Publisher Policy: Reproduced under a Creative Commons License