Theory 08/Physics, Cosmos & Matter /Particle physics
The Muon Anomaly Has an Onset
The anomaly is treated as a constant offset. A new particle would switch on.
A new light state contributing to the muon anomaly must produce an energy threshold, so the discrepancy should appear in low-energy measurements and vanish in high-energy ones rather than persisting uniformly.
01The evidence
The muon magnetic moment discrepancy has persisted across experiments and has not been confirmed by lattice calculations to the same precision.
02The tension
Analyses compare a single number across experiments. If the effect has an energy threshold, comparisons at different energies are not measuring the same thing.
03The mechanism
A light mediator contributes through a loop, and the contribution depends on the momentum transfer in the measurement. At energies above the mediator scale, the contribution is suppressed by the propagator.
That makes the anomaly energy-dependent, and predicts a step or a decline at the threshold that would appear as inconsistency between experiments at different scales.
04What this is not
Offset models compare one number. This predicts energy dependence, which changes which experiments should agree.
05Predictions
- P1The discrepancy should fall with momentum transfer.
- P2Low-energy experiments should agree with each other and not with high.
- P3A threshold should be identifiable.
06Refutation
A constant offset across energies would remove the threshold.
07What it changes
It would change how the anomaly is compared across experiments.