Virtual Messenger Matching Bypasses the Heavy Parent Threshold
Integrating out all three messenger stages transports the charged-cycle phase into a dimension-seven low-energy operator. The two complete tree paths have coefficients
and their ratio is the charged-cycle invariant. Unit constructive and destructive signs give matched coefficient squares four and zero.
At the exact WP637 closed point, the heavy-parent Källén polynomial is , while the virtual matched response remains finite and equals . Thus an on-shell heavy messenger decay is not required for the source-derived low-energy response.
This operation is neither a physical16 selector nor a calibrated physical
instrument. It adds a charged-scalar portal and leaves its invariant and heavy
masses free. An accessible charged-scalar channel with production, widths,
QCD transport, acceptance, and a common-normalization likelihood remains the
instrument gate.
Evidence: research/flavor/flavor-charged-cycle-low-energy-matching.md and
research/flavor/results/wp638_charged_cycle_low_energy_matching.json.