Progress on the exploratory calculation of the rare Hyperon decay $\Sigma^+ \to p \ell^+ \ell^-$

Abstract

The rare Hyperon decay Σ + → 𝑝ℓ + ℓ − is an 𝑠 → 𝑑 flavour changing neutral current process, which is highly suppressed within the Standard Model, and is therefore sensitive to new physics. Due to recent improvements in experimental measurements of this decay, the Standard Model theory prediction must also be improved in order to identify any new physics in this channel. We present updates on our progress towards the first exploratory lattice calculation of the long-distance part of the form factors of this decay. This pilot calculation is performed on a 340 MeV pion mass ensemble using domain-wall fermions as part of the RBC-UKQCD collaboration.

Quark flavor physics with lattice QCD

“…Bai-Long Hoid reviewed the application of the continuum, dispersive approach to 𝜋 0 → 𝑒 + 𝑒 − and 𝐾 𝐿 → 𝜇 + 𝜇 − and its relation to lattice QCD [191]. Raoul Hodgson gave an update [192] on the exploratory lattice calculation [185] of the rare hyperon decay Σ + → 𝑝ℓ + ℓ − . Amarjit Soni presented an overview of rare kaon decays and emphasized the role of 𝐾 0 → 𝜋 0 ℓ + ℓ − [193].…”