arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1004.4834hep-thhep-ph
收藏

重整化群改进的最优微扰理论:O(2N)Gross-Neveu模型质量隙的再研究

Renormalization Group Improved Optimized Perturbation Theory: Revisiting the Mass Gap of the O(2N) Gross-Neveu Model

J. -L. Kneur, A. Neveu

摘要:

我们引入了一个扩展的变分优化微扰方法,通过结合它与重整化群性质在一个简单的(微扰)形式。这导致了一个非常透明和有效的程序,与以前类似的变分方法的非微扰结果有明显的改善。这里通过导出O(2N)Gross-Neveu模型的质量间隙的优化结果来说明这一点,并与任意N的确切已知结果进行比较。在大N时,使用该过程在修正的扰动的第一阶已经再现了精确的结果。对于任意值的N,使用原来的微扰信息只知道在两个循环的顺序,我们得到一个可控的百分比精度或更少,对于任何N值,与确切地知道的结果相比,质量间隙从螺旋Bethe Anastrophe。该程序是非常一般的,可以直接扩展到任何可重正化的拉格朗日模型,被系统地改进,提供了足够的知识的有关数量的微扰阶。

英文摘要:

We introduce an extension of a variationally optimized perturbation method, by combining it with renormalization group properties in a straightforward (perturbative) form. This leads to a very transparent and efficient procedure, with a clear improvement of the non-perturbative results with respect to previous similar variational approaches. This is illustrated here by deriving optimized results for the mass gap of the O(2N) Gross-Neveu model, compared with the exactly know results for arbitrary N. At large N, the exact result is reproduced already at the very first order of the modified perturbation using this procedure. For arbitrary values of N, using the original perturbative information only known at two-loop order, we obtain a controllable percent accuracy or less, for any N value, as compared with the exactly known result for the mass gap from the thermodynamical Bethe Ansatz. The procedure is very general and can be extended straightforwardly to any renormalizable Lagrangian model, being systematically improvable provided that a knowledge of enough perturbative orders of the relevant quantities is available.

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。

↑