and unified theories on an elongated rectangle

Abstract

Maximally supersymmetric SO(10) and SU (6) unified theories are constructed on the orbifold T 2 /(Z 2 × Z ′ 2 ), with one length scale R 5 taken much larger than the other, R 6 . The effective theory below 1/R 6 is found to be the highly successful SU (5) theory in 5D with natural doublet-triplet splitting, no proton decay from operators of dimension four or five, unified mass relations for heavier generations only, and a precise prediction for gauge coupling unification. A more unified gauge symmetry, and the possibility of Higgs doublets being components of the higher dimensional gauge multiplet, are therefore compatible with a large energy interval where physics is described by SU (5) gauge symmetry in 5D. This leads to the distinctive branching ratios for proton decay from SU (5) gauge boson exchange, p → l + π 0 , l + K 0 ,νπ + ,νK + (l = e, µ), for well-motivated locations for matter. Several phenomenological features of the higher unified gauge symmetry are discussed, including the role of an extra U (1) gauge symmetry, which survives compactification, in the generation of neutrino masses.

Warped supersymmetric unification with a nonunified superparticle spectrum

“…Because the global SU(5) of G is dynamically broken, the spectrum of the towers does not respect SU (5), as shown in Eqs. (13,15). Moreover, the dynamical breaking of SU(5) to 321 produces Goldstone bosons, which correspond to the XY components of A 5 in an appropriate basis.…”

“…Thus our theory is not "grand unified" in the conventional sense. The correct normalization may be obtained by considering higher dimensional theories as in [15]; for instance by extending the y = 0 brane (the bulk) to a short 1-dimensional (thin 2-dimensional) object having SU(4) C × SU(2) L × SU(2) R (SO(10)) gauge symmetry. Alternatively, we could 2 An alternative choice for the boundary conditions of the Higgs fields is given by Eq.…”

Mass Ratio of W and Z Bosons in Su(5) Gauge-Higgs Unification

“…The two extra dimensions also involve two dimensionful quantities. The difference of the scales of the two extra dimensions can modify the values of low-energy physical quantities such as quark and charged lepton masses [11,12]. Thus the distribution for symmetry breaking and multiple dimensionful quantities might affect the mass ratio of W and Z bosons.…”

Gauge and Yukawa Couplings in 6d Supersymmetric Su(6) Models

“…We consider two cases where Higgs fields are 5D chiral superfields and they are a part of the 6D gauge multiplet. In this section, we consider a model where Higgs fields are 5D chiral superfields as a version with gaugino-mediated supersymmetry breaking of the model [7]. The starting parity matrices are given by…”

“…Our first model has the weak-doublet Higgs fields in 5D chiral superfields, which is a version with gauginomediated supersymmetry breaking of Ref. [7] where the doublet-triplet splitting, no proton decay from operators of dimension four or five, no mass relations for the first two generations and gauge coupling unification were achieved. Our other model has the Higgs doublets in the 6D gauge multipet, which is a 6D version with gaugino mediated supersymmetry breaking of Ref.…”