Z{yields}bb and chiral currents in Higgsless models

Journal Article · Wed Apr 01 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.075016· OSTI ID:21308207

Abe, Tomohiro; Tanabashi, Masaharu ^[1]; Chivukula, R Sekhar; Christensen, Neil D; Hsieh, Ken; Simmons, Elizabeth H ^[2]; Matsuzaki, Shinya ^[3]

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1. Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)
2. Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)
3. Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

In this paper we compute the flavor-dependent chiral-logarithmic corrections to the decay Z{yields}bb in the three-site Higgsless model. We compute these corrections diagrammatically in the gaugeless limit in which the electroweak couplings vanish. We also compute the chiral-logarithmic corrections to the decay Z{yields}bb using a renormalization group equation analysis in effective field theory, and show that the results agree. In the process of this computation, we compute the form of the chiral current in the gaugeless limit of the three-site model, and consider the generalization to the N-site case. We elucidate the Ward-Takahashi identities which underlie the gaugeless limit calculation in the three-site model, and describe how the result for the Z{yields}bb amplitude is obtained in unitary gauge in the full theory. We find that the phenomenological constraints on the three-site Higgsless model arising from measurements of Z{yields}bb are relatively mild, requiring only that the heavy Dirac fermion be heavier than 1 TeV or so, and are satisfied automatically in the range of parameters allowed by other precision electroweak data.

• OSTI ID: 21308207
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
CALCULATION METHODS
CHIRALITY
COMPUTERIZED SIMULATION
CORRECTIONS
COUPLING
EQUATIONS
FERMIONS
FIELD THEORIES
FLAVOR MODEL
HIGGS MODEL
PARTICLE DECAY
RENORMALIZATION
TEV RANGE 01-10
WEINBERG-SALAM GAUGE MODEL
Z NEUTRAL BOSONS