Quark-Hadron Phase Transition and Nucleosynthesis in Early Universe

从最近对非均匀宇宙核合成的研究中指出，1)omega_B=1模型与轻元素观测结果一致，2)包括r过程元素在内的重元素被大量合成，3)^9Be也被大量合成，起到了不均匀指示剂的作用。然而，这些建议是基于一个简单的双区模型，在该模型中，在核合成过程中忽略了中子的后扩散。本文的研究表明：1)与轻元素观测一致的omega_B的上限与均匀情况下的omega_B几乎相同，omega_B=0.06h^~(-2)~(-2)；(2)在合理的参数空间中，简单双区模型中的^9Be丰度被高估了至少两个数量级；

From recent studies of nucleosynthesis in inhomogeneous universe, it has been pointed out that 1) OMEGA_B=1model becomes consistent with light element observations, 2) heavy elements including r-process elements are abundantly synthesized, and 3) ^9Be plays a role of the indicator of inhomogeneity since ^9Be is also abundantly synthesized. These suggestions were, however, based on a simple two-zone model in which back diffusion of neutrons are neglected during the nucleosynthesis. In the present investigation, it was shown that 1) the upper limit of OMEGA_B which is consistent with light element observations is almost the same as that of homogeneous case, OMEGA_B=0.06h^<-2>,2) the ^9Be abundance in the simple two-zone model is overestimated at least two orders of magnitude in plausible parameter space and 3) the abundances of CNO elements are very small in the proper range of baryon/photon ratio consistent with the abundances of light elements.