The Phase structure of a chirally invariant lattice Higgs-Yukawa model
The Phase structure of a chirally invariant lattice Higgs-Yukawa model
复制标题
手性不变晶格希格斯-汤川模型的相结构
DOI：
10.1088/1126-6708/2007/09/041
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
K. Jansen
中科院分区：
文献类型：
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作者：
P. Gerhold;K. Jansen
我们考虑基于 Neuberger 重叠算子 (ov) 的手性不变晶格 Higgs-Yukawa 模型。作为最终确定希格斯质量界的第一步，我们在大 Nf 极限下分析研究了模型的相图。我们提出了小汤川和四次耦合常数范围内树级有效势的表达式，并确定了相变的顺序。在强汤川耦合的情况下，对于四次耦合常数的所有值，模型实际上变成 O(4) 对称非线性 σ 模型。这导致在汤川耦合常数大值的区域中也存在对称相。然而，在有限和小晶格上，强大的有限体积效应会阻止希格斯场的期望值消失，从而掩盖强汤川耦合下对称相位的存在。
We consider a chirally invariant lattice Higgs-Yukawa model based on the Neuberger overlap operator (ov). As a first step towards the eventual determination of Higgs mass bounds we study the phase diagram of the model analytically in the large Nf-limit. We present an expression for the effective potential at tree-level in the regime of small Yukawa and quartic coupling constants and determine the order of the phase transitions. In the case of strong Yukawa couplings the model effectively becomes an O(4)-symmetric non-linear σ-model for all values of the quartic coupling constant. This leads to the existence of a symmetric phase also in the regime of large values of the Yukawa coupling constant. On finite and small lattices, however, strong finite volume effects prevent the expectation value of the Higgs field from vanishing thus obscuring the existence of the symmetric phase at strong Yukawa couplings.