arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1011.4871hep-thgr-qchep-ph
收藏

大质量费米子物质对膨胀子的稳定作用

Dilaton stabilization by massive fermion matter

Alejandro Cabo, Matts Roos, Encieh Erfani

摘要:

本文的研究是在前人关于由于大质量费米子的存在所产生的有效势而使Dilaton平均场稳定化的工作中展开的。除了先前计算的两个回路项之外,还评估了三个回路校正。结果表明,与从弦论预测爱因斯坦引力的需要相一致,膨胀真空场趋于固定在一个接近普朗克尺度的高值。膨胀子的质量也被估计为接近普朗克质量的高值,这意味着在现代宇宙学观测中没有膨胀子标量信号。当费米子的质量被选择在一个与顶夸克质量相对应的下界,或者在一个假设在大统一能量范围内的高得多的值时,这些性质就会出现。三个3-循环项中的一个是根据Master积分精确计算的。然而,其他两个图的评估,在其领导的对数校正微扰展开。非主导对数贡献的计算和包含高回路项可以使真空场值和质量的数值估计更精确,但似乎预计不会改变所获得的定性行为。这里所采用的汤川模型近似的有效性被认为是小的费米子质量值相对于普朗克之一。在前面的工作中所做的两个回路计算的校正在这里下划线。

英文摘要:

The study started in a former work about the Dilaton mean field stabilization thanks to the effective potential generated by the existence of massive fermions, is here extended. Three loop corrections are evaluated in addition to the previously calculated two loop terms. The results indicate that the Dilaton vacuum field tend to be fixed at a high value close to the Planck scale, in accordance with the need for predicting Einstein gravity from string theory. The mass of the Dilaton is evaluated to be also a high value close to the Planck mass, which implies the absence of Dilaton scalar signals in modern cosmological observations. These properties arise when the fermion mass is chosen to be either at a lower bound corresponding to the top quark mass, or alternatively, at a very much higher value assumed to be in the grand unification energy range. One of the three 3-loop terms is exactly evaluated in terms of Master integrals. The other two graphs are however evaluated in their leading logarithm correction in the perturbative expansion. The calculation of the non leading logarithmic contribution and the inclusion of higher loops terms could made more precise the numerical estimates of the vacuum field value and masses, but seemingly are expected not to change the qualitative behavior obtained. The validity of the here employed Yukawa model approximation is argued for small value of the fermion masses with respect to the Planck one. A correction to the two loop calculation done in the previous work is here underlined.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑