TY - JOUR
T1 - A fermionic top partner
T2 - Naturalness and the LHC
AU - Berger, Joshua
AU - Hubisz, Jay
AU - Perelstein, Maxim
PY - 2012
Y1 - 2012
N2 - Naturalness demands that the quadratic divergence of the one-loop top contribution to the Higgs mass be cancelled at a scale below 1TeV. This can be achieved by introducing a fermionic (spin-1/2) top partner, as in, for example, Little Higgs models. In this paper, we study the phenomenology of a simple model realizing this mechanism. We present the current bounds on the model from precision electroweak fits, flavor physics, and direct searches at the LHC. The lower bound on the top partner mass from precision electroweak data is approximately 500 GeV, while the LHC bound with 5fb-1 of data at √s = 7TeV is about 450GeV. Given these bounds, the model can incorporate a 125GeV Higgs with minimal fine-tuning of about 20%. We conclude that natural electroweak symmetry breaking with a fermionic top partner remains a viable possibility. We also compute the Higgs decay rates into gauge bosons, and find that significant, potentially observable deviations from the Standard Model predictions may occur.
AB - Naturalness demands that the quadratic divergence of the one-loop top contribution to the Higgs mass be cancelled at a scale below 1TeV. This can be achieved by introducing a fermionic (spin-1/2) top partner, as in, for example, Little Higgs models. In this paper, we study the phenomenology of a simple model realizing this mechanism. We present the current bounds on the model from precision electroweak fits, flavor physics, and direct searches at the LHC. The lower bound on the top partner mass from precision electroweak data is approximately 500 GeV, while the LHC bound with 5fb-1 of data at √s = 7TeV is about 450GeV. Given these bounds, the model can incorporate a 125GeV Higgs with minimal fine-tuning of about 20%. We conclude that natural electroweak symmetry breaking with a fermionic top partner remains a viable possibility. We also compute the Higgs decay rates into gauge bosons, and find that significant, potentially observable deviations from the Standard Model predictions may occur.
KW - Beyond Standard Model
KW - Higgs physics
KW - Technicolor and composite models
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U2 - 10.1007/JHEP07(2012)016
DO - 10.1007/JHEP07(2012)016
M3 - Article
AN - SCOPUS:84864493625
SN - 1126-6708
VL - 2012
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 7
M1 - 16
ER -