Custodial isospin violation in the Lee-Wick standard model

Journal Article · Sat May 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.095015· OSTI ID:21409979

Chivukula, R Sekhar; Farzinnia, Arsham; Foadi, Roshan; Simmons, Elizabeth H ^[1]

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1. Department of Physics, Michigan State University, East Lansing, Michigan 48824 (United States)

We analyze the tension between naturalness and isospin violation in the Lee-Wick standard model (LW SM) by computing tree-level and fermionic one-loop contributions to the post-LEP electroweak parameters (S-circumflex, T-circumflex, W, and Y) and the Zb{sub L}b-bar{sub L} coupling. The model is most natural when the LW partners of the gauge bosons and fermions are light, but small partner masses can lead to large isospin violation. The post-LEP parameters yield a simple picture in the LW SM: the gauge sector contributes to Y and W only, with leading contributions arising at tree level, while the fermion sector contributes to S-circumflex and T-circumflex only, with leading corrections arising at one loop. Hence, W and Y constrain the masses of the LW gauge bosons to satisfy M{sub 1}, M{sub 2} > or approx. 2.4 TeV at 95% C.L. Likewise, experimental limits on T-circumflex reveal that the masses of the LW fermions must satisfy M{sub q}, M{sub t} > or approx. 1.6 TeV at 95% C.L. if the Higgs mass is light and tend to exclude the LW SM for any LW fermion masses if the Higgs mass is heavy. Contributions from the top-quark sector to the Zb{sub L}b{sub L} coupling can be even more stringent, placing a lower bound of 4 TeV on the LW fermion masses at 95% C.L.

• OSTI ID: 21409979
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 9; Other Information: DOI: 10.1103/PhysRevD.81.095015; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPUTERIZED SIMULATION
CORRECTIONS
COUPLING
HIGGS BOSONS
HIGGS MODEL
ISOSPIN
LEE MODEL
LEP STORAGE RINGS
MASS
STANDARD MODEL
T QUARKS
TEV RANGE 01-10
WEINBERG-SALAM GAUGE MODEL
ACCELERATORS
BOSONS
CYCLIC ACCELERATORS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FIELD THEORIES
GRAND UNIFIED THEORY
MATHEMATICAL MODELS
PARTICLE MODELS
PARTICLE PROPERTIES
POSTULATED PARTICLES
QUANTUM FIELD THEORY
QUARKS
SIMULATION
STORAGE RINGS
SYNCHROTRONS
TEV RANGE
TOP PARTICLES
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES