Regular Article - Theoretical Physics
Decays of the heavy top and new insights on in a one-VLQ minimal solution to the CKM unitarity problem
Departament de Física Teòrica and IFIC, Universitat de València-CSIC, 46100, Burjassot, Spain
2 Centro de Física Teórica de Partículas, CFTP, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais nr. 1, 1049-001, Lisboa, Portugal
Accepted: 6 April 2022
Published online: 25 April 2022
We propose a minimal extension of the Standard Model where an up-type vector-like quark, denoted T, is introduced and provides a simple solution to the CKM unitarity problem. We adopt the Botella-Chau parametrization in order to extract the quark mixing matrix which contains the three angles of the CKM matrix plus three new angles denoted , , . It is assumed that the mixing of T with standard quarks is dominated by . Imposing a recently derived, and much more restrictive, upper-bound on the New Physics contributions to , we find, in the limit of exact dominance where the other extra angles vanish, that is too large. However, if one relaxes the exact dominance limit, there exists a parameter region, where one may obtain in agreement with experiment while maintaining the novel pattern of T decays with the heavy quark decaying predominantly to the light quarks d and u. We also find a reduction in the decay rate of .
© The Author(s) 2022. corrected publication 2022
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