"Could Charm (\& $\tau$) Transitions be the `Poor Princesses' of Deeper Understanding of Fundamental Dynamics?" -- or -- "Finding Novel Forces?"

TL;DR

This paper explores the role of charm and tau transitions in understanding fundamental forces, emphasizing the importance of precision measurements, symmetry considerations, and experimental advancements in uncovering new physics beyond the Standard Model.

Contribution

It highlights the potential of charm and tau transitions as probes for new dynamics and emphasizes the need for high-precision experiments and symmetry analysis to deepen our understanding of fundamental interactions.

Findings

Charm dynamics bridge light and heavy flavor physics.

Regional asymmetries in many-body final states could be transformative.

Precision measurements at future factories are crucial for discovering new physics.

Abstract

We know that `our' Universe consists of `known' matter only $\sim$ 4.5\%: our understanding is incomplete seeing directly in neutrino oscillations (never mind about `other' Universes). Charm quarks had great impact on our understanding of known matter. QCD is the only local quantum field theory to describe strong forces. We can learn novel lessons about strong dynamics by measuring rates around the thresholds of $[\bar Q Q]$ states with $Q = b, c$. Furthermore they give us gateways for New Dynamics (ND), where we have to go from `accuracy' to `precision' eras. Finally we can connect with $\tau$ transitions and -- maybe -- with dark matter. Charm dynamics acts as a bridge between the worlds of light flavor hadrons with the heavy one, namely beauty hadrons. Finding {\em regional asymmetries} in many-body final states could be a `game changer'. There are several different `roads' to get closer to our goals: experiments act as gatekeepers like Super-tau-charm-factories, Super-beauty-factories and/or Super-$Z^0$-factories -- and deeper thinking about symmetries.