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Satya Nandi
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Left-right symmetric mirror model at the LHC
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The idea of left-right symmetry with mirror
fermions is very appealing from the symmetry
point of view. In this picture, unlike the
Standard Model, the symmetry is not only
left-right symmetric, but each left-handed
fermion multiplet is accompanied by a new
right-handed fermion multiplet of
opposite chirality. In this work, we consider
gauge symmetry, SU(3)_c x SU(2)_L xSU(2)_R
x U(1), supplemented by a discrete Z_2 symmetry.
Instead of having right-handed multiplets
for each left-handed multiplet of the same
fermions as in the usual left-right model,
the mirror model includes right- handed doublets
involving new fermions (called mirrors),
and similarly for each right- handed
singlet, there are corresponding mirror singlets.
Thus the gauge anomaly is naturally absent
in this model, and the model also provides
a solution for the strong CP problem because
of parity conservation. The first stage of
symmetry breaking is achieved by a doublet
mirror Higgs with a
vacuum expectation value 10^7 GeV, needed
to explain the neutrino mass of order 10^
{-11} GeV. The mirror fermions can mix with
the ordinary fermions via a scalar that is
singlet under the gauge symmetry. In this
model, only light mirror particles, having
masses in the few hundred GeV range, are
mirror-e, mirror-u, and mirror-d particles
with well-defined spectrum. mirror-u and
mirror-d particles can be pair produced at
the LHC and can be detected as (uZ) and (dZ)
resonances. We discuss the signals of these
mirror fermions at the LHC and find that
the reach at the
LHC can be as high as 800 GeV.
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