Leptophobic U(1)'s and the Rb-Rc anomalies.
In this paper, we investigate the possibility of explaining both the R_b excess and the R_c deficit reported by the LEP experiments through Z-Z' mixing effects. We have constructed a set of models consistent with a restrictive set of principles: unification of the Standard Model (SM) gauge coup...
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| Format: | Journal article |
| Language: | English |
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1996
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| _version_ | 1826267892950237184 |
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| author | Babu, K Kolda, C March-Russell, J |
| author_facet | Babu, K Kolda, C March-Russell, J |
| author_sort | Babu, K |
| collection | OXFORD |
| description | In this paper, we investigate the possibility of explaining both the R_b excess and the R_c deficit reported by the LEP experiments through Z-Z' mixing effects. We have constructed a set of models consistent with a restrictive set of principles: unification of the Standard Model (SM) gauge couplings, vector- like additional matter, and couplings which are both generation-independent and leptophobic. These models are anomaly-free, perturbative up to the GUT scale, and contain realistic mass spectra. Out of this class of models, we find three explicit realizations which fit the LEP data to a far better extent than the unmodified SM or MSSM and satisfy all other phenomenological constraints which we have investigated. One realization, the \eta-model coming from E_6, is particularly attractive, arising naturally from geometrical compactifications of heterotic string theory. This conclusion depends crucially on the inclusion of a U(1) kinetic mixing term, whose value is correctly predicted by renormalization group running in the E_6 model given one discrete choice of spectra. |
| first_indexed | 2024-03-06T21:01:14Z |
| format | Journal article |
| id | oxford-uuid:3af30ad8-3975-4d99-9afb-10a32e6ad46d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:01:14Z |
| publishDate | 1996 |
| record_format | dspace |
| spelling | oxford-uuid:3af30ad8-3975-4d99-9afb-10a32e6ad46d2022-03-26T14:04:41ZLeptophobic U(1)'s and the Rb-Rc anomalies.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3af30ad8-3975-4d99-9afb-10a32e6ad46dEnglishSymplectic Elements at Oxford1996Babu, KKolda, CMarch-Russell, JIn this paper, we investigate the possibility of explaining both the R_b excess and the R_c deficit reported by the LEP experiments through Z-Z' mixing effects. We have constructed a set of models consistent with a restrictive set of principles: unification of the Standard Model (SM) gauge couplings, vector- like additional matter, and couplings which are both generation-independent and leptophobic. These models are anomaly-free, perturbative up to the GUT scale, and contain realistic mass spectra. Out of this class of models, we find three explicit realizations which fit the LEP data to a far better extent than the unmodified SM or MSSM and satisfy all other phenomenological constraints which we have investigated. One realization, the \eta-model coming from E_6, is particularly attractive, arising naturally from geometrical compactifications of heterotic string theory. This conclusion depends crucially on the inclusion of a U(1) kinetic mixing term, whose value is correctly predicted by renormalization group running in the E_6 model given one discrete choice of spectra. |
| spellingShingle | Babu, K Kolda, C March-Russell, J Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title | Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title_full | Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title_fullStr | Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title_full_unstemmed | Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title_short | Leptophobic U(1)'s and the Rb-Rc anomalies. |
| title_sort | leptophobic u 1 s and the rb rc anomalies |
| work_keys_str_mv | AT babuk leptophobicu1sandtherbrcanomalies AT koldac leptophobicu1sandtherbrcanomalies AT marchrussellj leptophobicu1sandtherbrcanomalies |