We present a new Little Higgs model, motivated by the deconstruction of a
five-dimensional gauge-Higgs model. The approximate global symmetry is
SO(5)0​×SO(5)1​, breaking to SO(5), with a gauged subgroup of
[SU(2)0L​×U(1)0R​]×O(4)1​, breaking to SU(2)L​×U(1)Y​. Radiative corrections produce an additional small vacuum misalignment,
breaking the electroweak symmetry down to U(1)EM​. Novel features of this
model are: the only un-eaten pseudo-Goldstone boson in the effective theory is
the Higgs boson; the model contains a custodial symmetry, which ensures that
T^=0 at tree-level; and the potential for the Higgs boson is generated
entirely through one-loop radiative corrections. A small negative mass-squared
in the Higgs potential is obtained by a cancellation between the contribution
of two heavy partners of the top quark, which is readily achieved over much of
the parameter space. We can then obtain both a vacuum expectation value of
v=246 GeV and a light Higgs boson mass, which is strongly correlated with the
masses of the two heavy top quark partners. For a scale of the global symmetry
breaking of f=1 TeV and using a single cutoff for the fermion loops, the
Higgs boson mass satisfies 120 GeV ≲MH​≲150 GeV over much of
the range of parameter space. For f raised to 10 TeV, these values increase
by about 40 GeV. Effects at the ultraviolet cutoff scale may also raise the
predicted values of the Higgs boson mass, but the model still favors
MH​≲200 GeV.Comment: 32 pages, 10 figures, JHEP style. Version accepted for publication in
JHEP. Includes additional discussion of sensitivity to UV effects and
fine-tuning, revised Fig. 9, added appendix and additional references