Abstract
We study the exclusive semileptonic decays Υ(1S)→ B(c)ℓ(v)ℓ,where ℓ=e,μ,τ.The relevant hadronic form factors are calculated using the covariant confined quark model developed previously by our group.We pre-dict the branching fractions B(Υ(1S)→ B(c)ℓ(v)ℓ)to be of the order of 10-13 and 10-10 for the case of B and B c,re-spectively.Our predictions agree well with other theoretical calculations.We also consider the effects of possible new physics in the case of Υ(1S)→ B cτ(v)τ and show that the branching fraction of this decay can be enhanced by an order of magnitude using constraints from the B →D(*)ℓ(v)ℓ and B c → J/Ψℓ(v)ℓ experimental data.
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