Program: GS-2008B-Q-51

Two massive clusters with an unprecedented red supergiant population and located at the base of the Scutum-Crux arm have been recently identified by Figer et al. (2006) and Davies et al. (2007). These clusters contain the largest numbers of red supergiants which formed in one star formation event in the Milky Way. The combination of location and sample size makes these stars a particularly useful tool with which to probe the chemistry at a key position in the Galaxy -- namely the interface between the inner disk and nuclear bar. We will obtain high-resolution infrared spectra of red supergiants in order to determine quantitative abundances of a set of elements that will allow us to characterize the chemical evolution that has taken place in this poorly studied region of the Milky Way. The chemical abundance distributions at the disk-bar interface can be compared to the rest of the Galactic disk and provide important boundary conditions on the behavior of metallicity gradients across the Galactic disk and into the nuclear region.