Search for baryon and lepton number violation decay $D^{\pm}\to n(\bar{n})e^{\pm}$

TL;DR

This study searches for baryon and lepton number violating decays of D mesons using BESIII data, setting upper limits on their branching fractions due to no observed signals, thus constraining new physics models.

Contribution

First search for specific baryon and lepton number violating decays of D mesons at BESIII, establishing upper limits on their branching fractions.

Findings

No signal observed for the decays.

Upper limits on branching fractions set at 1.43×10⁻⁵ and 2.91×10⁻⁵.

Constraints placed on models predicting baryon and lepton number violation.

Abstract

Using a data set of electron-positron collisions corresponding to an integrated luminosity of ${\rm 2.93~fb^{-1}}$ taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, a search for the baryon ($B$) and lepton ($L$) number violating decays $D^{\pm}\to n(\bar{n})e^{\pm}$ is performed. No signal is observed and the upper limits on the branching fractions at the $90\%$ confidence level are set to be $1.43\times10^{-5}$ for the decays $D^{+(-)}\to \bar{n}(n)e^{+(-)}$ with $\Delta|B-L|=0$, and $2.91\times10^{-5}$ for the decays $D^{+(-)}\to n(\bar{n})e^{+(-)}$ with $\Delta|B-L|=2$ , where $\Delta|B-L|$ denotes the change in the difference between baryon and lepton numbers.