Implications of a New Temperature Scale for Halo Dwarfs on LiBeB and Chemical Evolution

Big bang nucleosynthesis (BBN) and the cosmic baryon density from cosmicmicrowave background anisotropies together predict a primordial Li7 abundance afactor of 2--3 higher than that observed in galactic halo dwarf stars. A recentanalysis of Li7 observations in halo stars, using significantly higher surfacetemperature for these stars, found a higher Li plateau abundance. These resultsgo a long way towards resolving the discrepancy with BBN. Here, we examine theimplications of the higher surface temperatures on the abundances of Be and Bwhich are thought to have been produced in galactic cosmic-ray nucleosynthesisby spallation of CNO together with Li (produced in alpha + alpha collisions).While the Be abundance is not overly sensitive to the surface temperature, thederived B abundances and more importantly the derived oxygen abundances arevery temperature dependent. If the new temperature scale is correct, theimplied increased abundances of these elements poses a serious challenge tomodels of galactic cosmic ray nucleosynthesis and galactic chemical evolution.Comment: 23 pages, 10 eps figure