the Li-7/Li-6 Isotope Ratio Near the Supernova Remnant IC 443
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We present an analysis of Li-7/Li-6 isotope ratios along four sight lines that probe diffuse molecular gas near the supernova remnant IC 443. Recent gamma-ray observations have revealed the presence of shock-accelerated cosmic rays interacting with the molecular cloud surrounding the remnant. Our results indicate that the Li-7/Li-6 ratio is lower in regions more strongly affected by these interactions, a sign of recent Li production by cosmic rays. We find that Li-7/Li-6 approximate to 7 toward HD 254755, which is located just outside the visible edge of IC 443, while Li-7/Li-6 approximate to 3 along the line of sight to HD 43582, which probes the interior region of the supernova remnant. No evidence of Li-7 synthesis by neutrino-induced spallation is found in material presumably contaminated by the ejecta of a core-collapse supernova. The lack of a neutrino signature in the Li-7/Li-6 ratios near IC 443 is consistent with recent models of Galactic chemical evolution, which suggest that the nu-process plays only a minor role in Li production.