Review of Charm Lifetimes

TL;DR

This review summarizes recent experimental findings on charm particle lifetimes, highlighting the larger D_s^+ lifetime compared to D^0 and exploring the implications for W-exchange and W-annihilation contributions in charm decays.

Contribution

It provides a comprehensive overview of experimental charm lifetime measurements and phenomenologically assesses the strength of W-exchange and W-annihilation contributions, challenging existing theoretical expectations.

Findings

D_s^+ lifetime is conclusively larger than D^0 lifetime.

W-exchange and W-annihilation contributions are larger than or at the limit of theoretical predictions.

New high statistics data enables phenomenological extraction of decay contribution strengths.

Abstract

A review of the latest experimental results on charm particle lifetimes is presented. The most significant update is that the D_s^+ lifetime is conclusively larger than the D^0 lifetime and signifies that W-exchange/W-annihilation contributions are large. Using new high statistics data on $D^+\to K^+\pi^+\pi^-$ together with the D_s^+ lifetime and some assumptions, one can phenomenologically extract the strength of the W-exchange contribution in D^0 decays and of W-annihilation in D_s^+ decays. These are larger than or at the limit of theoretical expectations using QCD-based operator production expansion techniques.