KMT-2023-BLG-2669: Ninth Free-floating Planet Candidate with ₄ measurements

We report a free-floating planet (FFP) candidate identified from the analysis of the microlensing event KMT-2023-BLG-2669. The lensing light curve is characterized by a short duration (3\, days) and a small amplitude (0. 7\, mag). From the analysis, we find the Einstein timescale of t ₄ 0. 33\, days and the Einstein radius of ₄ 4. 41\, as. These measurements enable us to infer the lens mass as M = 8\, M_ (ₑ₄₋ / 0. 1\, mas) ^-1, where ₑ₄₋ is the relative lens-source parallax. The inference implies that the lens is a sub-Neptune- to Saturn-mass object depending on its unknown distance. This is the ninth isolated planetary-mass microlens with ₄ < 10\, as, which (as shown by gould22) is a useful threshold for a FFP candidate. We conduct extensive searches for possible signals of a host star in the light curve, but find no strong evidence for the host. We discuss the possibility of using late-time high-resolution imaging to probe for possible hosts.