HealthBench Professional: Evaluating Large Language Models on Real Clinician Chats. - Rebecca Soskin Hicks; Mikhail Trofimov; Dominick Lim; Rahul K. Arora; Foivos Tsimpourlas; Preston Bowman; Michael Sharman; Chi Tong; Kavin Karthik; Arnav Dugar; Akshay Jagadeesh; Khaled Saab 003; et al. (CoRR, 2026)