Effective potential and vacuum stability within universal extra dimensions

Abstract

The one-loop effective potential calculated for a generic model that originates from 5-dimensional theory reduced down to 4 dimensions is considered. The cut-off and dimensional regularization schemes are discussed and compared. It is demonstrated that the prescriptions are consistent with each other and lead to the same physical consequences. Stability of the ground state is discussed for a U(1) model that is supposed to mimic the Standard Model extended to 5 dimensions. It has been shown that fermionic Kaluza-Klein modes can dramatically influence the shape of the effective potential shifting the instability scale even by several orders of magnitude.

Precise calculation of the relic density of Kaluza-Klein dark matter in universal extra dimensions

“…The simplest version of UED has all the SM particles propagating in a single extra dimension of size R, which is compactified on an S 1 /Z 2 orbifold. More complicated models have also been considered, motivated by ideas about electroweak symmetry breaking and vacuum stability [13][14][15], neutrino masses [16,17], proton stability [18], the number of generations [19] or fermion chirality [20,21]. A peculiar feature of UED is the conservation of Kaluza-Klein number n at tree level, which is a simple consequence of momentum conservation along the extra dimension.…”

Discrimination of supersymmetry and universal extra dimensions at hadron colliders

“…More complicated 6-dimensional models have also been built [15,16]. The UED framework has been a fruitful playground for addressing different puzzles of the Standard Model, such as electroweak symmetry breaking and vacuum stability [17,18,19], neutrino masses [20,21], proton stability [22] or the number of generations [23]. A peculiar feature of UED is the conservation of Kaluza-Klein number at tree level, which is a simple consequence of momentum conservation along the extra dimension.…”

Search for Higgs bosons of the universal extra dimensions at the large Hadron collider

“…The presence of KK-towers for charged and neutral CP-odd Higgs bosons provides a concrete example of this. The phenomenology of KK-excitations has been studied in great detail in recent times which covers its implications at colliders [3,4,5,6,7,8,9,10,11,12,13,14,15,16], in electroweak/flavour sector via various low-energy observables [17,18,19,20,21,22,23,24,25,26,27,28] and for dark matter/cosmology [5,13,29,30,31,32,33,34,35,36,37,38,39,40] In MUED there are only two extra free parameters when compared to the SM. These are the radius of compactification R (or, alternately R −1 , the scale of compactification) and the cutoff scale Λ of the theory.…”