We measured 36 Ar(p ជ ,p 0 ) cross sections and analyzing powers for E p between 3.22 and 5.98 MeV, and used these data to deduce spin, parity, and widths of 17 levels in 37 K. Our results, combined with existing information on 37 Ca ␤ ϩ decay, yield information on the distribution of Fermi and Gamow-Teller strength in this decay. A Tϭ1/2 level lying 31 keV below the J ϭ3/2 ϩ , Tϭ3/2 analog of the 37 Ca ground state was found to have J ϭ3/2 ϩ . The relative proton widths of the two levels imply an isospin-mixing matrix-element of 4.84Ϯ0.43 keV. This agrees with the value 5.93 Ϫ0.65 ϩ0.23 keV extracted from the ␤ ϩ -decay intensities to the two levels, plus the Gamow-Teller to Fermi strength ratio for the 5018 keV level. We decompose the Gamow-Teller strength in 37 Ca decay into components feeding daughter levels with J ϭ1/2 ϩ , 3/2 ϩ , or 5/2 ϩ , and compare the results to theory. None of the available shell-model calculations gives a satisfactory account of the data. ͓S0556-2813͑97͒00602-X͔

The system of CH3I adsorbed on submonolayer, monolayer, and multilayer thin films of D2O on Cu(110) has been studied by measuring the time of flight (TOF) distributions of the desorbing CH3 fragments after photodissociation using linearly polarized λ = 248 nm light. For multilayer D2O films (2-120 ML), the photodissociation is dominated by neutral photodissociation via the "A-band" absorption of CH3I. The polarization and angle dependent variation in the observed TOF spectra of the CH3 photofragments find that dissociation is largely via the (3)Q0 excited state, but that also a contribution via the (1)Q1 excitation can be identified. The photodissociation results also indicate that the CH3I adsorbed on D2O forms close-packed islands at submonolayer coverages, with a mixture of C-I bond axis orientations. For monolayer and submonolayer quantities of D2O we have observed a contribution to CH3I photodissociation via dissociative electron attachment (DEA) by photoelectrons. The observed DEA is consistent with delocalized photoelectrons from the substrate causing the observed dissociation- we do not find evidence for an enhanced DEA mechanism via the temporary solvation of photoelectrons in localized states of the D2O ice.

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