Bulk renormalization and particle spectrum in codimension-two brane worlds

8th Biennial Conference on Classical and Quantum Relativistic Dynamics of Particles and Fields

Salvio, Alberto^1,2

Scuola Normale Superiore, INFN, Piazza dei Cavalieri 7, 56126 Pisa, Italy^1

Departamento de Física Teórica, Universidad Autónoma de Madrid, Instituto de Física Teórica IFT-UAM/CSIC, Cantoblanco, 28049 Madrid, Spain^2

关键词: Codimension-two;    Compactification;    Cosmological constants;    Dimensional regularization;    Effective field theory;    Extra dimensions;    Particle spectra;    The standard model;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/437/1/012004/pdf
DOI  :  10.1088/1742-6596/437/1/012004

来源: IOP

【 摘 要 】

We study the Casimir energy due to bulk loops of matter fields in codimension-two brane worlds and discuss how effective field theory methods allow us to use this result to renormalize the bulk and brane operators. In the calculation we explicitly sum over the Kaluza-Klein (KK) states with a new convenient method, which is based on a combined use of zeta function and dimensional regularization. Among the general class of models we consider we include a supersymmetric example, 6D gauged chiral supergravity. Although much of our discussion is more general, we treat in some detail a class of compactifications, where the extra dimensions parametrize a rugby ball shaped space with size stabilized by a bulk magnetic flux. The rugby ball geometry requires two branes, which can host the Standard Model fields and carry both tension and magnetic flux (of the bulk gauge field), the leading terms in a derivative expansion. The brane properties have an impact on the KK spectrum and therefore on the Casimir energy as well as on the renormalization of the brane operators. A very interesting feature is that when the two branes carry exactly the same amount of flux, one half of the bulk supersymmetries survives after the compactification, even if the brane tensions are large. We also discuss the implications of these calculations for the natural value of the cosmological constant when the bulk has two large extra dimensions and the bulk supersymmetry is partially preserved (or completely broken).