宇宙中的光子数、重子数、及反重子数

THE NUMBER OF PHOTONS, BARYONS AND ANTIBARYONS IN THE UNIVERSE

在粒子物理与宇宙学二者的结合上,近年已经取得了颇有意义的进展。重子不对称和重子光子数比的起源可以用大统一理论加以解释。由B、C及CP破坏的相互作用可以说明为什么初始重子对称的宇宙能演化成不对称的。目前观测到的重子光子数比10^(-9)可能是由极早期宇宙中的超重玻色子的衰变产生的,在这种衰变中C及CP是破坏的。尽管衰变解释是吸引入的,但它的具体预言很强地依赖于超重玻色子的质量,以致其数值尚不确定。因此。为了进一步考查衰变模型的合理性,至少还要研究其他的可能有影响的过程。在这个意义下,本文还讨论了宇宙早期中的Higgs相变对重子光子比的影响。

In recent years the significant progress have been made in the development of a comprehensive understanding of particle physics and cosmo logy. The origin of the baryon asymmetry and the baryon-to-photon ratio may be explained by Grand Unified Theories.It has been shown that B, C and CP violating interactions allow an initially baryon symmetrical universe to evolve a baryon asymmetry. The observed baryon-to-photon ratio of 10-9 could be produced by the decays of superheavy bosons in the very early universe if C and CP are violated in its actions. While this decay explanation is in the fashion, it depends strongly on the masses of the Higgs and the gauge particles so that the predicted value of nB/nγ may be either smaller or larger than 10-9. Therefore, it is needed, for the proof of the decay model, to examine other processes which possibly have significant effect on the evolution of the number of photons, baryons and antibaryons in the universe. For this reason the effect of Higgs phase transition on the baryon-to-photon ratio are discussed.