Supersymmetric Higgs bosons in a 5D orbifold model

Abstract

We analyze the phenomenology of the Higgs sector in a 5D model compactified on an S 1 /Z 2 orbifold where the compactification scale M C is around the TeV scale. We show that the conventional MSSM Higgs boson mass bounds in 4D can be violated when we allow the gauge sector, Higgs and third family multiplets to live in the fifth extra dimension. Supersymmetry is broken at an orbifold fixed point which is spatially separated from the Yukawa brane where two chiral families are localized. When the brane-localized supersymmetry breaking term for the stop sector is arbitrarily large, we find that the stop KK-mode mass spectrum is completely independent of the Higgs fields. Hence, the Higgs masses only receive radiative contributions from the top KK-modes. The 1-loop effective potential is insensitive to the cutoff scale of the theory and yields a negative Higgs squared-mass contribution that triggers electroweak symmetry breaking in the range 1.5 < ∼ tan β < ∼ 20, where bottom/sbottom loop effects can be ignored. The recent LEP Higgs bound at m h 0 > 114.1 GeV, in conjunction with naturalness arguments, allows us to bracket the compactification scale 1.5 < ∼ M C < ∼ 4 TeV. Within this parameter space, we find that the lightest Higgs boson mass has an upper bound m h 0 < ∼ 160 GeV with the magnitude of the µ-parameter restricted to the range 33 < ∼ |µ| < ∼ 347 GeV.

The lightest Higgs boson mass in effective field theory with bulk and brane supersymmetry breaking

“…We derive stop mass in an orbifold model with the Standard Model gauge bosons, third generation of quarks and leptons and two Higgs fields and their superpartners as fivedimensional bulk fields, in similar to the model given in Refs. [7,8]. And then we obtain correction to the Higgs boson mass.…”

“…In the upper bound (3.18) to the lightest Higgs boson mass, there are contributions largely from the second and third terms. If α itself is very small and m t ∼ αR −1 , the Higgs boson mass would be corrected for a large R −1 such as grand unification scale [8]. Now we consider supersymmetry breaking by the Scherk-Schwarz twist and F -term on a brane.…”

“…Because the contribution from each mode is summed, supersymmetry breaking with extra dimensions may increase the corrections to Higgs boson masses. In the context of extra dimensions, effective potentials and Higgs boson masses have been widely studied [8][21]- [35].…”

“…When the radius of an extra dimension is denoted as R, the mass splitting between a bulk field and its supersymmetric partner can be of the order of R −1 with a factor of order O(1). This type of mass splitting is obtained by F -term supersymmetry breaking on a brane [2][6]- [8] or independently by Scherk-Schwarz supersymmetry breaking [9]- [20]. If R −1 ∼ 1 TeV, corrections to the Higgs mass would be significant.…”

“…In the last equation, Eqs. (3.8),(3.15) and(3.17) have also been used.4 The mass-eigenvalue splitting with bulk and brane supersymmetry breakingWe derive stop mass in an orbifold model with the Standard Model gauge bosons, third generation of quarks and leptons and two Higgs fields and their superpartners as fivedimensional bulk fields, in similar to the model given in Refs [7,8]…”