Probing invisible particles with charm
O(10^−1). On the other hand, if models are probed, branching ratios still reach up to 10^−3 (Z′) and 10^−4 (ALPs). Chirality-preserving operators from heavy new physics in the dimension six standard model effective [...] dimension seven SMEFT, or with light sterile neutrinos, are weaker, with branching ratios up to few ×10^−4. Sensitivities to different couplings arise with Λc→pX and D→ππX decays, in particular in relation with …
