Nondecoupling of a terascale isosinglet quark and rare K and B decays

Picek, Ivica and Radovčić, Branimir (2008) Nondecoupling of a terascale isosinglet quark and rare K and B decays. Physical Review D, 78 (1). pp. 15014-7. ISSN 1550-7998

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Abstract

We examine recent extensions of the standard model with an up-type vectorlike isosinglet T quark that mixes dominantly with the top quark. We take under scrutiny the nondecoupling effects which may reveal such a new heavy fermion through loop diagrams relevant for rare decays such as K-->pi nu nu-bar, B-->pi(K) nu nu-bar, and B_{; ; ; ; s, d}; ; ; ; -->mu^+ mu^-. After demonstrating in detail the cancellation between the leading nondecoupling terms, we show that two residual forms ~ s^2 ln{; ; ; ; m_T^2}; ; ; ; and ~ s^4 m_T^2 act in complementary way, so that the maximal allowed values of the decay rates are practically independent of m_T. While they correspond to ~ 20% or ~ 30% corrections to the SM rates for K-->pi nu nu-bar and B-->pi(K) nu nu-bar, an increase by ~ 50% for B_{; ; ; ; s, d}; ; ; ; -->mu^+ mu^- decays offers a possibility to reveal an additional isosinglet state by measurements of these decays at the Large Hadronic Collider.

Item Type: Article
Keywords: models beyond the SM ; electroweak transitions ; decays of K and B mesons
Date: July 2008
Subjects: NATURAL SCIENCES > Physics > Physics of Elementary Particles and Fields
Additional Information: Copyright (2008) by the American Physical Society.
Divisions: Faculty of Science > Department of Physics
Project code: 119-0982930-1016
Publisher: American Physical Society
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 27 May 2014 19:34
Last Modified: 27 May 2014 19:34
URI: http://digre.pmf.unizg.hr/id/eprint/1826

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