Search for Baryon and Lepton Number Violating Z0 Decays

TL;DR

This study searched for rare Z0 decays violating baryon and lepton number conservation using OPAL data, setting upper limits on such processes with no evidence found.

Contribution

First experimental search for Z0 decays violating baryon and lepton number, establishing new upper limits on these rare processes.

Findings

No evidence for B and L violating Z0 decays

Upper limits set at 4.6 keV for Z0 -> p e-

Upper limits set at 4.4 keV for Z0 -> p mu-

Abstract

Using data collected with the OPAL detector at LEP, we have searched for the processes e+e- -> Z0 -> p e-, p mu- and the charge conjugate final-states. These would violate the conservation of the baryon-number B, lepton-number L and the fermion-number n = (B+L). No evidence for such decays has been found, and the 95% confidence level upper limits on the partial widths Z0 -> p e and Z0 -> p mu are found to be 4.6 and 4.4 keV respectively.