Answers are grounded in this paper and cite their sources.
Improved study of the antiprotonic helium hyperfine structure, Pask, T, Barna, D, Dax, A, Hayano, R S, Hori, M, Horváth, D, Juhász, B, Malbrunot, C, Marton, J, Ono, N, Suzuki, K, Zmeskal, J, Widmann, E
No takes yet. Share an insight, caveat, or question.
A 2008 study studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: