Impact ofZ′and universal extra dimension parameters on different asymmetries inBs→ϕℓ+ℓ

Ishtiaq Ahmed

¹

,

M. Jamil Aslam

²

,

M. Ali Paracha

³

Abstract

A comprehensive study of the impact of new physics on different observables for B s ! ' þ ' À is carried out. We examine the new physics models, such as Z 0 and universal extra dimension models, where the effects of new physics come through the modification of Wilson coefficients. We analyze these effects through the theoretical prediction of the branching ratio, the forward-backward asymmetry, lepton polarization asymmetries, and the helicity fractions of the final-state meson. These observables will definitely be measured in present and future colliders with great precision. We also point out that hadronic uncertainties in various physical observables are small, which make them an ideal probe to establish new physics. Therefore, the measurements of these observables for the same decay would permit the detection of physics beyond the Standard Model and will also help us to distinguish between different new physics scenarios.

Study of B s ⟶ ϕ ℓ

“…It is much smaller than the total theoretical errors, say around 30-40%. According to the argument in Reference [68], the term Y res ðq 2 Þ is also generally small. Because of its smallness and the possible double-counting problem, we here simply drop the term Y res ðq 2 Þ out in our numerical evaluations for all physical observables considered in this paper.…”

Implication of Z-mediated FCNC on semileptonic decays Bs→φl+l–and B+→K+l+l–

“…The semileptonic B meson decay channels and have the quark level transition . For this transition the effective Hamiltonian can be presented as [31,[36][37][38][39] √ ∑ where are four-quark operators, are dipole operators and are semileptonic electroweak operators given in [40,41].…”

“…Now the short distance function is elaborately written as [36,42] Basically they can be summerized in form of phenomenological Breit-Weigner formula. In our study, we have excluded this long distance resonance portion because it is far away from the part of our interest and experimental analysis also ignore this [30,31,55]. From eq.…”

“…Such a type of rare semileptonic B decay induced by quark level transition are comparatively clean than the hadronic transitions and so it is expected that they are sensitive to some new interactions, such as 2HDM [23], supersymmetric theories [24], leptoquarks [25], non-universal model [26] , single universal extra dimension [27] etc. Another type of such semileptonic rare B decays having quark level transition are studied in various models, as scalar leptoquarks [28], supersymmetric [29], single universal extra dimension [30], non-universal Z' model and universal extra dimension model [31] and 331-Z' model [32].…”