Spectrum structure of a fermion on Bloch branes with two scalar–fermion couplings. (14th February 2017)

• Record Type: Journal Article
• Authors: Xie, Qun-Ying; Guo, Heng; Zhao, Zhen-Hua; Du, Yun-Zhi; Zhang, Yu-Peng
• Is Part Of: Classical and quantum gravity. Volume 34:Number 5(2017:Mar.)
• Publication Date: 2017-02-14
• Subjects: field theories in higher dimensions -- extra dimension -- mass spectrum; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/aa5ad6
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: It is known that the Bloch brane is generated by an odd scalar field ϕ and an even one χ . In order to localize a bulk fermion on the Bloch brane, the coupling between the fermion and scalars should be introduced. There are two localization mechanisms in the literature, the Yukawa coupling − η Ψ ̄ F 1 ( ϕ, χ ) Ψ and non-Yukawa coupling λ Ψ ̄ Γ M ∂ M F 2 ( ϕ, χ ) γ 5 Ψ . The Yukawa coupling has been considered. In this paper, we consider both couplings between the fermion and the scalars with F 1 = χ m ϕ 2 p + 1 and F 2 = χ n ϕ 2 q, and investigate the localization and spectrum structure of the fermion on the Bloch brane. It is found that the left-handed fermion zero mode can be localized on the Bloch brane under some conditions, and the effective potentials have rich structure and may be volcano-like, finite square well-like, and infinite potentials. As a result, the spectrum consists of a series of resonant Kaluza–Klein fermions, finite or infinite numbers of bound Kaluza–Klein fermions. Especially, we find a new feature of the introduction of both couplings: the spectrum for the case of finite square well-like potentials contains discrete quasi-localized and localized massive KK modes simultaneously.