This question is directed mostly at people who are expert in (beyond) standard model(s) of elementary particles, but input by other physicists or students is very much appreciated.
A friend asked me about a new discovery at CERN in March 2021 that I wasn't aware of it until now. Let me explain this discovery first. Quarks can decay into leptons and the standard model predicts that bottom (beauty) quarks would decay into muons at the same rate as they do into electrons. But, the experimental results of CERN reveal that the quarks appeared to decay into muon less often than they decayed into electrons (around 85 muon decays for every 100 electron decays). This evidence signals that some before unseen particle or a new force are involved in the decay process! As they claimed, this means the need for a better theory beyond the standard theory will become clearer.
If the experimental data are correct (according to the news, results are really strong since the uncertainty of the result is over three sigma, but not enough yet), what will be the properties of the new particle or (perhaps) the new force? This observation cannot be explained within the current state of physics?