Intermediate-scale vertex corrections for zero mode in warped space

Non-Abelian gauge theory with a warped extra dimension is studied as a quantum field theory at an intermediate scale that is regarded as being much lower than the scale of the geometry stabilization and the Planck scale. Loop corrections for zero-mode vertices are diagrammatically calculable in perturbation at the intermediate scale. The contribution for each diagram can be compared to the correspondent in the four-dimensional theory. It is found that for a part of the contributions the coefficient for the logarithmic scaling has the same value as the four-dimensional results. A viewpoint to treat corrections associated with higher-dimensional operators is also discussed.Comment: 15 pages, 6 figures; v2: analysis modified, a figure adde

Selecting Gauge Theories on an Interval by 5D Gauge Transformations

Gauge symmetry breaking by boundary conditions is studied in a general warped geometry in five dimensions. It has been suggested that a wider class of boundary conditions is allowed by requiring only vanishing surface terms when deriving the field equations for gauge theories on an interval (i.e., employing a variational principle), in comparison to the twist in orbifolding with automorphisms of the Lie algebra. We find that there are classes of boundary conditions allowed by the variational principle which violate the Ward-Takahashi identity and give four-point tree amplitudes that increase with energy in channels that have not yet been explored, leading to cross sections that increase as powers of the energy (which violates the tree level unitarity). We also find that such boundary conditions are forbidden by the requirement that the definitions of the restricted class of five-dimensional (5D) gauge transformations be consistent.Comment: 21 pages, 4 figures; typos corrected(v2), a footnote added for section 3(v3), added explanations(v4), typos corrected, a part of section 2.3 restructured and paragraphs added for section 3(v5), presentation modified and typos corrected(v6), PTP version(v7

Total-derivative supersymmetry breaking

On an interval compactification in supersymmetric theory, boundary conditions for bulk fields must be treated carefully. If they are taken arbitrarily following the requirement that a theory is supersymmetric, the conditions could give redundant constraints on the theory. We construct a supersymmetric action integral on an interval by introducing brane interactions with which total derivative terms under the supersymmetry transformation become zero due to a cancellation. The variational principle leads equations of motion and also boundary conditions for bulk fields, which determine boundary values of bulk fields. By estimating mass spectrum, {\it spontaneous} supersymmetry breaking in this simple setup can be realized in a new framework. This supersymmetry breaking does not induce massless R-axion, which is favorable for phenomenology. It is worth noting that fermions in hyper-multiplet, gauge bosons, and the fifth-dimensional component of gauge bosons can have zero-modes (while the other components are all massive as Kaluza-Klein modes), which fits the gauge-Higgs unification scenarios.Comment: 9 pages, a clarification about boundary conditions adde