Scaling of the Higgs self-coupling and bounds on the extra dimension

In this paper we study the one-loop evolution equation of the Higgs quartic coupling λ in the minimal universal extra dimension model, and find that there are certain bounds on the extra dimension due to the singularity and vacuum stability conditions of the Higgs sector. In the range 250GeV∼R ^-1∼80TeV of the compactification radius, we notice that for a given initial value λ(M_Z), there is an upper limit on R ^-1 for a Higgs mass of 183GeV∼m_H(M_Z) ∼187GeV; where any other compactification scales beyond that have been ruled out for theories where the evolution of λ does not develop a Landau pole and become divergent in the whole range (that is, from the electroweak scale to the unification scale). Likewise, in the range of the Higgs mass 152GeV∼m_H(M_Z)∼157GeV, for an initial value λ(M_Z), we are led to a lower limit on R^-1; any other compactification scales below that will be ruled out for theories where the evolution of λ does not become negative and destabilize the vacuum between the electroweak scale and the unification scale. For a Higgs mass in the range 157GeV<m_H(M_Z)<183GeV, the evolution of λ is finite and the theory is valid in the whole range (from the electroweak scale to the unification scale) for 250GeV∼R ^-1∼80TeV.