Test of Time-Reversal Invariance through the ReactionsMg24+α⇌Al27+p

Time-reversal invariance has been tested via detailed balance in the compound nuclear reactions ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}+\alpha \rightleftharpoons {}_{}{}^{27}{}_{}{}^{}\mathrm{Al}+p$. The relative differential cross sections agree within the experimental uncertainties. An upper limit for the ratio of the $T$-nonconserving to the $T$-conserving part of the reaction amplitude has been found to be (2-3)×${10}^{-3\mathrm{}}$. A model-dependent upper limit between 4×${10}^{-4\mathrm{}}$ and 3×${10}^{-3\mathrm{}}$ has been derived for the relative strength of the $T$-odd part of the nuclear Hamiltonian.