A Material Frame: Hard Recoils from Slow Force Carriers
arXiv:2607.27253
The paper proposes a modification of the Standard Model where the photon’s longitudinal component becomes a physical, ultra‑slow mode, breaking gauge and Lorentz invariance, and studies the resulting Cherenkov‑like recoils of charged particles, deriving extremely strong bounds from dark‑matter detector data.
Abstract
We modify the Standard Model by making the longitudinal component of the photon physical, propagating with small speed . This modification breaks gauge invariance and Lorentz symmetry, defining a preferred reference frame. No new fields or scales are introduced, and the photon mass is protected by a Galilean higher-form symmetry. The theory has a smooth limit: the new modes decouple from standard matter and ordinary gauge theory predictions are recovered. Experimental constraints are severe. Charged particles Cherenkov-emit these slow modes, experiencing hard recoils against the preferred frame. The recoil rate decreases with , but the momentum transfer remains of the order of the particle's momentum. Dark matter detectors, sensitive to keV-scale nuclear recoils, imply an order-of-magnitude bound , tens of orders of magnitude stronger than speed-difference bounds. At such values, is better understood as a recoil-rate factor rather than a physically relevant speed. The slow modes, practically fixed in space, make the reference frame a material medium capable of absorbing momentum from charged particles.
27 pages + Appendix