Hunt for geometric phase effects in H + HD → HD(v′, j′) + H

An attempt has been made to measure the theoretically predicted manifestation of a geometric phase in the differential cross section for the H + HD → HD(v' = 2, j' = 5) + H reaction at a center-of-mass collision energy of 1.44 eV (33.2 kcal∕mol). Minute oscillatory differences between calculated differential cross sections that take into account and ignore the effect of geometric phase have proven to be beyond our experimental resolution in spite of the collection of more than 44,000 ions.