Constraints on the Formation of the Galactic Bulge from Na, Al, and
  Heavy Element Abundances in Plaut's Field
  We report chemical abundances of Na, Al, Zr, La, Nd, and Eu for 39 red giant
branch (RGB) stars and 23 potential inner disk red clump stars located in
Plaut-s low extinction window. We also measure lithium for a super Li-rich RGB
star. The abundances were determined by spectrum synthesis of high resolution
(R~25,000), high signal-to-noise (S/N~50-100 pixel-1) spectra obtained with the
Blanco 4m telescope and Hydra multifiber spectrograph. For the bulge RGB stars,
we find a general increase in the [Na/Fe] and [Na/Al] ratios with increasing
metallicity, and a similar decrease in [La/Fe] and [Nd/Fe]. Additionally, the
[Al/Fe] and [Eu/Fe] abundance trends almost identically follow those of the
{\alpha}-elements, and the [Zr/Fe] ratios exhibit relatively little change with
[Fe/H]. The consistently low [La/Eu] ratios of the RGB stars indicate that at
least a majority of bulge stars formed rapidly (<1 Gyr) and before the main
s-process could become a significant pollution source. In contrast, we find
that the potential inner disk clump stars exhibit abundance patterns more
similar to those of the thin and thick disks. Comparisons between the abundance
trends at different bulge locations suggest that the inner and outer bulge
formed on similar timescales. However, we find evidence of some abundance
differences between the most metal-poor and metal-rich stars in various bulge
fields. The data also indicate that the halo may have had a more significant
impact on the outer bulge initial composition than the inner bulge composition.
The [Na/Fe] and to a lesser extent [La/Fe] abundances further indicate that the
metal-poor bulge, at least at ~1 kpc from the Galactic center, and thick disk
may not share an identical chemistry.
