Updated constraints on two quark, two lepton operators

TL;DR

This paper updates constraints on four-fermion operators involving two quarks and two leptons, derived from various experimental processes, refining bounds on potential beyond Standard Model physics.

Contribution

It provides the latest bounds on these operators using experimental data from 2008, updating previous constraints and improving our understanding of possible new physics effects.

Findings

Updated bounds on four-fermion operator coefficients

Constraints derived from rare decays and atomic parity violation

Refined limits on beyond Standard Model interactions

Abstract

Physics from beyond the Standard Model can induce four fermion operators involving a quark, an anti-quark, a lepton and an anti-lepton. The coefficients of these operators can be constrained by various observations. We update the bounds arising from tree level processes (rare lepton and meson decays, atomic parity violation, contact interaction and mu-e conversion) using experimental values given in the Particle Data Book 2008.