arXiv subjects

Nurgul Habyl

Publications and source records attributed to Nurgul Habyl.

3 recordsLinked to original sources

arXiv2015

Decay $B\to K^\ast(\to Kπ) \ell^+ \ell^-$ in covariant quark model

Our article is devoted to the study of the rare $B\to K^\ast \ell^+\ell^-$~decay where $\ell=e,μ,τ$. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the cascade decay $B\to K^\ast(\to Kπ)\ell^+\ell^-$. We compare the obtained results with available experimental data and the results from other theoretical approaches.

hep-ph↗

arXiv2015

Physical observables in the decay $Λ_b \to Λ_c (\to Λ+π)+τ^{-}+\bar ν_τ$

We analyze the tauonic semileptonic baryon decays $Λ^0_b \to Λ^+_c + τ^{-} +\bar ν_τ$ with particular emphasis on the lepton helicity flip contributions which vanish for zero lepton masses. We calculate the total rate, differential decay distributions, the longitudinal and transverse polarization components of the $Λ^+_c$ and the $τ^-$, and the lepton-side forward-backward asymmetries. We use the covariant confined quark model to provide numerical results on these observables.

hep-ph↗

arXiv2015

The semileptonic decay Lambda_b -> Lambda_c + tau(-) + antinu_tau in the covariant confined quark model

Recently there has been much interest in the tauonic semileptonic meson decays B -> D + tau + nu_tau and B -> D* + tau + nu_tau where one has found larger rates than what is predicted by the Standard Model. We analyze the corresponding semileptonic baryon decays Lambda_b(0) -> Lambda_c(+) + tau(-) + antinu_tau with particular emphasis on the lepton helicity flip and scalar contributions which vanish for zero lepton masses. We calculate the total rate, differential decay distributions, the longitudinal and transverse polarization of the daughter baryon Lambda_c(+) and the tau-lepton, and the lepton-side forward-backward asymmetries. The nonvanishing polarization of the daughter baryon Lambda_c(+) leads to hadron-side asymmetries in e.g. the decay Lambda_c(+) -> Lambda(0) + pi(+) and azimuthal correlations between the two final state decay planes which we specify. We provide numerical results on these observables using results of the covariant confined quark model. We find large lepton mass effects in the q2-spectra and in the polarization observables.

hep-ph↗