# Ultracold Collisions of Polyatomic Molecules: CaOH

## TL;DR

This paper investigates ultracold collisions of CaOH molecules, showing that efficient evaporative cooling is feasible with electric field tuning and predicting the formation of long-lived dimer states.

## Contribution

It provides the first detailed analysis of ultracold collisions for polyatomic molecules like CaOH, highlighting the role of dipole interactions and electric fields in cooling efficiency.

## Key findings

- Evaporative cooling can be efficient for CaOH at achievable temperatures.
- Electric fields enhance the rate constants favorable for cooling.
- Long-lived dimer states (CaOH)₂* are predicted with microsecond lifetimes.

## Abstract

Ultracold collisions of the polyatomic species CaOH are considered, in internal states where the collisions should be dominated by long-range dipole-dipole interactions. The computed rate constants suggest that evaporative cooling can be quite efficient for these species, provided they start at temperatures achievable by laser cooling. The rate constants are shown to become more favorable for evaporative cooling as the electric field increases. Moreover, long-range dimer states (CaOH)$^*_2$ are predicated to occur, having lifetimes on the order of microseconds.