Observable Proton Decay from Planck Scale Physics

TL;DR

This paper explores how Planck-scale physics could induce observable proton decay, especially in models with light non-singlet bosons, leading to specific decay modes that conserve B+L.

Contribution

It identifies conditions under which Planck-scale effects can produce detectable proton decay modes involving light bosons, expanding understanding of baryon number violation.

Findings

Proton decay amplitudes can be enhanced to observable levels with light non-singlet bosons.

Dominant decay modes include p → π+ ν and p → π+ π+ ℓ−, conserving B+L.

Standard Model alone suppresses Planck-scale proton decay due to dimension-5 operators.

Abstract

In the Standard Model, no dim-5 $\Delta B \neq 0$ operators exist, so that Planck-scale-induced proton decay amplitudes are suppressed by at least $1/M^2_{P \ell}$. If the Standard Model is augmented by a light, color-non-singlet boson, then $O(1/M_{P \ell})$ proton-decay amplitudes are possible. These always conserve $B+L$, so that the dominant decay modes are $p \rightarrow \Pi^+ \nu$ and $p \rightarrow \Pi^+ \Pi^+ \ell^-$, where $\Pi^+ = \pi^+$ or $K^+$.