Radiative lifetime of the $a{}^3{\Sigma }^{+}$ state of HeH${}^{+}$ from ab initio calculations

J. Loreau, J. Liévin, N. Vaeck

The first metastable triplet state of HeH${}^{+}$ was found to be present in ion beam experiments, with its lifetime estimated to be between hundreds of milliseconds and thousand of se…