Neutral Kaon Mixing Beyond the Standard Model with $n_f=2+1$ Chiral Fermions Part 1: Bare Matrix Elements and Physical Results

Abstract

We compute the hadronic matrix elements of the four-quark operators relevant for $K^0-{\bar{K}}^0$ 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 ($a\sim 0.08$ and $a\sim 0.11 \, \fm $) and with lightest unitary pion mass $\sim 300\, \MeV$. 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 $\sim 5\%$ or better.

38 pages

References in corpus (7)

• Twisted mass lattice QCD
• Present and Future K and B Meson Mixing Constraints on TeV Scale Left-Right Symmetry
• Continuum Limit of $B_K$ from 2+1 Flavor Domain Wall QCD
• K^0-\bar K^0 mixing beyond the standard model and CP-violating electroweak penguins in quenched QCD with exact chiral symmetry
• BK-parameter from Nf = 2 twisted mass lattice QCD
• Neutral kaon mixing beyond the standard model with nf=2+1 chiral fermions
• Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing

Cited by in corpus (14)

• FLAG Review 2021
• $\Delta M_s$ theory precision confronts flavour anomalies
• FLAG Review 2024
• Kaon CP violation and neutron EDM in the minimal left-right symmetric model
• Effective field theory approach to lepton number violating decays $K^{\pm }\to {\pi }^{\mp }{l}^{\pm }{l}^{\pm }$: short-distance contribution
• Lattice QCD Inputs for Nuclear Double Beta Decay
• Light sterile neutrinos and lepton-number-violating kaon decays in effective field theory
• RI-(S)MOM to $\overline{\mathrm{MS}}$ conversion for $B_K$ at two-loop order
• Cosmological implications of the KOTO excess
• Quark flavor physics and lattice QCD
• Vector-like quark doublets, weak-basis invariants and CP violation
• Nuclear EDM from SMEFT flavor-changing operator
• The Optimal Strategy for ${\epsilon }^{\prime }/\epsilon$ in the SM: 2019
• Non-perturbative renormalisation with interpolating momentum schemes