Testing Supersymmetry by Means of Time Reversal Invariance

The minimal supersymmetric extension of the standard model allows for some of the coupling strengths to be complex parameters. The presence of such imaginary phases can lead to violations of time reversal invariance, which can be tested if correlations in products of an odd number of polarizations and momenta are measured and found to be different from zero. As an example, we consider the triple product $\mbox{\bf J} \cdot \left(\mbox{\bf p}_1 \times \mbox{\bf p}_ {2} \right)$ in the $\beta$-decay of the neutron, of the $\Sigma^-$, and in the decay $K^{+}_{3\mu}$. For these low-energy decays, we find that the present experimental precision is not enough to provide useful bounds on combinations of such phases and the masses of the supersymmetric particles. At higher energies, the same time reversal violating correlation in the semileptonic decay of the $t$ quark is of the order of $\alpha_s/\pi$, made bigger by the large mass of the decaying quark.