Physical Review Letters
Atomic two-photon J = 0 ↔ J′ = 1 transitions are forbidden for photons of the same energy. This selection rule is related to the fact that photons obey Bose-Einstein statistics. We have searched for small violations of this selection rule by studying transitions in atomic Ba. We set a limit on the probability v that photons are in exchange-antisymmetric states: v < 1.2 × 10-7.
© 1999 The American Physical Society.
De Mille, D.; Budker, D.; Derr, N.; and Deveney, E., "Search for Exchange-Antisymmetric Two-Photon States" (1999). Biological Sciences: Faculty Publications, Smith College, Northampton, MA.