Slice imaging is used to measure directly the alignment of Br( 2 P 3/2 ) and Cl( 2 P 3/2 ) photofragments from the photodissociation of Br 2 and Cl 2 , respectively, at 355 nm, using an intensity-normalization method that does not require the wavelength scanning of the probe laser. In both cases the C 1 ⌸(1 u ) state is optically excited. The Br photofragments are maximally aligned and populate m J ϭϮ1/2 only, whereas the Cl photofragments populate both the m J ϭϮ1/2 and m J ϭϮ3/2 by 80% and

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... , respectively. These results show that Br 2 dissociates adiabatically, whereas nonadiabatic transitions occur to the A 3 ⌸(1 u ) during Cl 2 dissociation.