Heavy Thermal Dark Matter from a New Collision Mechanism

We propose a new thermal freezeout mechanism which results in dark matter masses exceeding the unitarity bound by many orders of magnitude, without violating perturbative or modifying standard cosmology. The process determining relic abundance is $\chi \zeta^\dagger \to \zeta \zeta$, where $\chi$ candidate. For $ m_\zeta < m_\chi 3 m_\zeta$, cosmologically long-lived and scatters against exponentially more abundant $\zeta$. Therefore, such allows for heavier same interaction strength as particle undergoing ordinary $2 2$ freezeout; equivalently, weaker interactions mass. demonstrate this leptophilic model, up to $10^{9}$ GeV.