Non-perturbative renormalisation of four-fermion operators in N_f=2 QCD

TL;DR

This paper reports on the non-perturbative renormalisation of four-fermion operators in N_f=2 QCD, including their renormalisation group running and total renormalisation factors across different lattice regularisations.

Contribution

It provides a comprehensive non-perturbative renormalisation framework for four-fermion operators in N_f=2 QCD, covering both relativistic and static heavy quark operators.

Findings

Renormalisation group running computed in the continuum limit.

Total renormalisation factors determined for various lattice regularisations.

Analysis includes operators relevant for ΔB=2 processes.

Abstract

We present results for the non-perturbative renormalisation of four-fermion operators with two flavours of dynamical quarks. We consider both fully relativistic left current-left current operators, and a full basis for $\Delta B=2$ operators with static heavy quarks. The renormalisation group running of the operators to high energy scales is computed in the continuum limit for a family of Schroedinger Functional renormalisation schemes, via standard finite size scaling techniques. The total renormalisation factors relating renormalisation group invariant to bare operators are computed for a choice of lattice regularisations.