Rare decaysBs→l+l−andB→Kl+l−<

Abstract

We examine the rare decays B s ! l þ l À and B ! Kl þ l À in the framework of the topcolor-assisted technicolor (TC2) model. The contributions of the new particles predicted by this model to these rare decay processes are evaluated. We find that the values of their branching ratios are larger than the standard model predictions by one order of magnitude in wide range of the parameter space. The longitudinal polarization asymmetry of leptons in B s ! l þ l À can approach Oð10 À2 Þ. The forward-backward asymmetry of leptons in B ! Kl þ l À is not large enough to be measured in future experiments. We also give some discussions about the branching ratios and the asymmetry observables related to these rare decay processes in the littlest Higgs model with T-parity.

Implications of LHCb measurements and future prospects

“…Littlest Higgs model with T -parity or Topcolour-assisted Technicolor), models with extra dimensions (e.g. RandallSundrum models) or models with fourth generation fermions can modify B(B 0 s → μ + μ − ) [116,[131][132][133][134][135]. The NP contributions from these models usually arise via (C 10 -C 10 ), and they are therefore correlated with the constraints from other b → s + − processes, e.g.…”

Analysis of the semileptonicΛb→Λℓ+ℓ−transition in the topcolor-assisted technicolor model

“…This model predicts the existence of top-pions (π 0,± t ), the top-Higgs (h 0 t ) and the non-universal gauge boson (Z ′ ), which we are going to discuss the dependences of the physical quantities defining the Λ b → Λℓ + ℓ − transition on the masses of these objects in this article. For more details of the TC2 model and some of its applications see for instance [9][10][11][12] and references therein. We also present the transition matrix elements in terms of form factors in full QCD and calculate the transition amplitude of the Λ b → Λℓ + ℓ − in both models.…”

“…The functions Y T C2 (y t ) and Z T C2 (y t ) are given by the following expressions in the case of e or µ in the final state [11,12]: …”

“…Since, the neutral topHiggs coupling with fermions differ from that of neutral top-pion by a factor of γ 5 , the form of C Q 2 is the same as C Q 1 except for the masses of the scalar particles [11].…”

Non-Abelian Vortex-String Dynamics From Nonlinear Realization

“…The other terms are higher order corrections to the brane actions up to the order of quartic derivatives. Besides, additional fermionic degrees of freedom can also be located on the brane world volume to describe its oscillations into the superspace for BPS [21,22] and non-BPS branes [23,24] in supersymmetric theories.…”