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$A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons
We explore models with additional right-handed gauge bosons that couple predominantly to the third generation in the context of $b\bar{b}$ production at LEP. In particular we investigate potential new contributions to $\delta g_{Rb}$ that are needed if the measured $A^b_{FB}$ at the $Z$ peak is inte...
Autores principales: | , |
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Lenguaje: | eng |
Publicado: |
2003
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1103/PhysRevD.68.033011 http://cds.cern.ch/record/614046 |
_version_ | 1780900276880801792 |
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author | He, X G Valencia, G |
author_facet | He, X G Valencia, G |
author_sort | He, X G |
collection | CERN |
description | We explore models with additional right-handed gauge bosons that couple predominantly to the third generation in the context of $b\bar{b}$ production at LEP. In particular we investigate potential new contributions to $\delta g_{Rb}$ that are needed if the measured $A^b_{FB}$ at the $Z$ peak is interpreted as a signal of new physics. We identify two sources of large $\delta g_{Rb}$ corrections: $Z-Z^\prime$ mixing at tree-level, and one-loop effects from a new $SU_R(2)$ triplet of gauge bosons. We find that the latter can contribute to $\delta g_{Rb}$ at the 1%-level. We place bounds on the mass of the additional $Z^\prime$ gauge boson that occurs in these models using the $R_b$ measurements from LEP-II. We find that even in cases where the $Z^\prime$ couples almost exclusively to the $b$ and $t$-quarks, masses lighter than about 500 GeV are already excluded. |
id | cern-614046 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2003 |
record_format | invenio |
spelling | cern-6140462019-09-30T06:29:59Zdoi:10.1103/PhysRevD.68.033011http://cds.cern.ch/record/614046engHe, X GValencia, G$A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge BosonsParticle Physics - PhenomenologyWe explore models with additional right-handed gauge bosons that couple predominantly to the third generation in the context of $b\bar{b}$ production at LEP. In particular we investigate potential new contributions to $\delta g_{Rb}$ that are needed if the measured $A^b_{FB}$ at the $Z$ peak is interpreted as a signal of new physics. We identify two sources of large $\delta g_{Rb}$ corrections: $Z-Z^\prime$ mixing at tree-level, and one-loop effects from a new $SU_R(2)$ triplet of gauge bosons. We find that the latter can contribute to $\delta g_{Rb}$ at the 1%-level. We place bounds on the mass of the additional $Z^\prime$ gauge boson that occurs in these models using the $R_b$ measurements from LEP-II. We find that even in cases where the $Z^\prime$ couples almost exclusively to the $b$ and $t$-quarks, masses lighter than about 500 GeV are already excluded.hep-ph/0304215oai:cds.cern.ch:6140462003-04-23 |
spellingShingle | Particle Physics - Phenomenology He, X G Valencia, G $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title | $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title_full | $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title_fullStr | $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title_full_unstemmed | $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title_short | $A^b_{FB}$ and $R_b$ at LEP and New Right-Handed Gauge Bosons |
title_sort | $a^b_{fb}$ and $r_b$ at lep and new right-handed gauge bosons |
topic | Particle Physics - Phenomenology |
url | https://dx.doi.org/10.1103/PhysRevD.68.033011 http://cds.cern.ch/record/614046 |
work_keys_str_mv | AT hexg abfbandrbatlepandnewrighthandedgaugebosons AT valenciag abfbandrbatlepandnewrighthandedgaugebosons |