Original scientific paper
A study of the fourth-generation quarks and FCNC
Surath Kumar Biswas
; Theoretical Physics Department, Indian Association for the Cultivation of Science, Jadavpur, Calcutta, 700032, India
Vinod Prakash Gautam
; Theoretical Physics Department, Indian Association for the Cultivation of Science, Jadavpur, Calcutta, 700032, India
Abstract
The decay of the fourth-generation down-type quark b' → bγ and b' → bg has been studied as an extension of the standard model using evolution of the mass-based fourth generation CKM matrix with CP violation phase equal to zero. Range of the masses of fourth generation down-type quark b' and up-type quark t' have been taken with due observance of the constraint imposed by the present experimental value of the ρ parameter, keeping in view the mass difference of the fourth generation quark doublet. The decay width of b' → bγ also has been studied, however, with correction up to the leading QCD logarithms for six active flavours after the W boson, t and t' quarks have been integrated out using operator product expansion. Strong interaction coupling constant is taken on matching scale of Z boson mass.
Keywords
fourth-generation of quarks; decay and masses of down-type quark b' and up-type quark t'; ρ doublet; decay width of b' → bγ
Hrčak ID:
303821
URI
Publication date:
2.8.1998.
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