Neutral kaon mixing beyond the Standard Model with nf=2+1 chiral fermions part II: Non Perturbative Renormalisation of the $\Delta F=2$ four-quark operators

Abstract

We compute the renormalisation factors (Z-matrices) of the $\Delta F=2$ four-quark operators needed for Beyond the Standard Model (BSM) kaon mixing. We work with nf=2+1 flavours of Domain-Wall fermions whose chiral-flavour properties are essential to maintain a continuum-like mixing pattern. We introduce new RI-SMOM renormalisation schemes, which we argue are better behaved compared to the commonly-used corresponding RI-MOM one. We find that, once converted to MS, the Z-factors computed through these RI-SMOM schemes are in good agreement but differ significantly from the ones computed through the RI-MOM scheme. The RI-SMOM Z-factors presented here have been used to compute the BSM neutral kaon mixing matrix elements in the companion paper [1]. We argue that the renormalisation procedure is responsible for the discrepancies observed by different collaborations, we will investigate and elucidate the origin of these differences throughout this work.

References in corpus (8)

• $K\to \pi \pi$ $\Delta I=3/2$ decay amplitude in the continuum limit
• Non-perturbative renormalization of quark bilinear operators and B_K using domain wall fermions
• K^0-\bar K^0 mixing beyond the standard model and CP-violating electroweak penguins in quenched QCD with exact chiral symmetry
• Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the RI/SMOM schemes
• Step Scaling with off-shell renormalisation
• Neutral kaon mixing beyond the standard model with nf=2+1 chiral fermions
• Precise MS-bar light-quark masses from lattice QCD in the RI/SMOM scheme
• Matching factors for Delta S=1 four-quark operators in RI/SMOM schemes

Cited by in corpus (7)

• FLAG Review 2021
• 50 Years of Quantum Chromodynamics
• FLAG Review 2024
• Neutrinoless Double Beta Decay from Lattice QCD: The Short-Distance ${\pi }^{-}\to {\pi }^{+}{e}^{-}{e}^{-}$ Amplitude
• $\Delta I=3/2$ and $\Delta I=1/2$ channels of $K\to \pi \pi$ decay at the physical point with periodic boundary conditions
• Quark flavor physics and lattice QCD
• Non-perturbative renormalisation with interpolating momentum schemes