The Effects of Fourth Generation on the Total Branching Ratio and the Lepton Polarization in $Λ_b \rar Λ\ell^+ \ell^-$ decay

Abstract

This study investigates the influence of the fourth generation quarks on the total branching ratio and the single lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay. Taking $|V_{t^{\prime }s}{V}_{t^{\prime }b}|0.01-0.03withphasejustbelow$90^\circ$, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Δm_{B_s}, we obtain that the total branching ratio and the single lepton(μ, τ) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks(t', b').

21 pages, 9 figures

References in corpus (3)

• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• The Cosmological Parameters 2006
• Fourth Generation CP Violation Effect on B -> K pi, phi K and rho K in NLO PQCD

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• CP-Conserving Unparticle Phase Effects on the Unpolarized and Polarized Direct CP Asymmetry in $b\to d{\ell }^{+}{\ell }^{-}$ Transition
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• Analysis of Various Polarization Asymmetries In The Inclusive $b\to s{\ell }^{+}{\ell }^{-}$ Decay In The Fourth-Generation Standard Model
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