NPR step-scaling across the charm threshold

Understand

Matching Non-Perturbative Renormalisation on the lattice and perturbative renormalisation would benefit from higher matching scales, which are needed for observables entering their permile era such as BK.

• In this work we lay down a strategy, within the Rome-Southampton framework, to push this scale higher across the charm threshold, and apply it to an exploration of the BK running from 3 GeV to 9 GeV.
• This is done on Nf = 2+1+1 ensembles generated by the RBC-UKQCD collaboration, and features a close study of the discretisation effects.