Improved Upper Limits on Baryon-Number Violating Dinucleon Decays to Dileptons

TL;DR

This paper derives improved upper limits on baryon-number violating dinucleon decays to dileptons by relating them to existing bounds on hadronic decay modes, resulting in significantly stronger constraints than direct searches.

Contribution

It establishes a method to infer tighter bounds on dilepton decay modes from existing hadronic decay limits, enhancing constraints on baryon-number violation.

Findings

Derived upper bounds on dinucleon decays to dileptons are substantially stronger than direct experimental limits.

Established a connection between hadronic decay bounds and dilepton decay constraints.

Provided estimates for upper limits on various dilepton decay channels.

Abstract

We consider effects of $n-\bar n$ oscillations and resultant matter instability due to dinucleons decays. We point out that existing upper bounds on the rates for the dinucleon decays $nn \to 2\pi^0$, $nn \to \pi^+\pi^-$, and $np \to \pi^+\pi^0$ imply upper bounds on the rates for dinucleon decays to dileptons $nn \to e^+ e^-$, $nn \to \mu^+\mu^-$, $nn \to \nu_\ell \bar\nu_\ell$, and $np \to \ell^+ \nu_\ell$, where $\ell=e, \ \mu, \ \tau$. We present estimates for these upper bounds. Our bounds are substantially stronger than corresponding limits from direct searches.