Double Lepton Polarization in ${\Lambda }_b-->\Lambda l^{+}{l}^{-}$ Decay in the Standard Model with Fourth Generations Scenario

Abstract

This study investigates the influence of the fourth generation quarks on the double lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase \{60^\circ,90^\circ,120^\circ\}. We will try to obtain a constrain on the mass of the 4th generation top like quark t', which is consistent with the $b--> s\ell^+\ell^- rate . With the above mentioned parameters, we will try to show that the double lepton(muon, tau) 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') via its indirect manifestations in loop diagrams.

36 pages, 33 figures

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• Lepton Polarization Asymmetry in B\to\ell^{+}\ell^{-} decay Beyond the Standard Model
• Polarized forward-backward asymmetries of leptons in (B_s -> l^+ l^- gamma) decay
• A Simple Approach to Fourth Generation Effects in $B\to X_s{\ell }^{+}{\ell }^{-}$ Decay

Cited by in corpus (14)

• Analysis of $Λ_b \rar Λ\ell^+ \ell^-$ transition in SM4 using form factors from Full QCD
• Rare baryon decays Lambda_b -> Lambda l+ l- (l=e, mu, tau) and Lambda_b -> Lambda gamma : Differential and total rates, lepton- and hadron-side forward-backward asymmetries
• Rare dileptonic decays of Λ_b in a quark model
• Measurement of the differential branching fraction of the decay ${\Lambda }_b^0\to \Lambda {\mu }^{+}{\mu }^{-}$
• Lepton mass effects and angular observables in ${\Lambda }_b\to \Lambda (\to p\pi ){\ell }^{+}{\ell }^{-}$
• Lepton polarization asymmetries for FCNC decays of the ${\Lambda }_b$ baryon
• The Effects of Fourth Generation on the double Lepton Polarization in B \rar K \ell^+ \ell^- decay
• CP-Conserving Unparticle Phase Effects on the Unpolarized and Polarized Direct CP Asymmetry in $b\to d{\ell }^{+}{\ell }^{-}$ Transition
• The ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$ decay in the aligned two-Higgs-doublet model
• Exclusive $B \rar ρ\ell^+ \ell^-$ Decay in the Standard Model with Fourth--Generation
• Rare baryonic decays ${\Lambda }_b\to \Lambda l^{+}{l}^{-}$ in the TTM model
• Double-Lepton Polarization Asymmetries in $B_s \rar ϕ\ell^+ \ell^-$ Decay in the Fourth-Generation Standard Model
• Analysis of Angular Observables of ${\Lambda }_b\to \Lambda (\to p\pi ){\mu }^{+}{\mu }^{-}$ Decay in Standard and $Z^{\prime }$ Models
• Semileptonic B to Scalar meson Decays in the Standard Model with Fourth Generation