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.Comment: 26 page

Physical observables in the decay Λb→Λc(→Λ+π)+τ−+νˉτ\Lambda_b \to \Lambda_c (\to \Lambda+\pi)+\tau^{-}+\bar \nu_{\tau}

We analyze the tauonic semileptonic baryon decays $\Lambda^0_b \to \Lambda^+_c + \tau^{-} +\bar \nu_{\tau}$ 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 $\Lambda^+_c$ and the $\tau^-$, and the lepton-side forward-backward asymmetries. We use the covariant confined quark model to provide numerical results on these observables.Comment: 6 pages, 1 figure. Talk given by Nurgul Habyl at the 9th joint International HADRON STRUCTURE'15 Conference, GRAND HOTEL BELLEVUE, Horny Smokovec, Slovak Republic, 29 June - 3 July, 201

Semileptonic decay Ʌb→Ʌc+τ͞͞ +͞͞ν τ in the covariant confined quark model

Recently there has been much interest in the tauonic semileptonic meson decays B→D+τ+ντ and B→D∗+τ+ντ, where one has found larger rates than what is predicted by the Standard Model. We analyze the corresponding semileptonic baryon decays Λ0b→Λ+c+τ−+ν¯τ with particular emphasis on the lepton helicity flip and scalar contributions which vanish for zero lepton masses. We calculate the total rate, the differential decay distributions, the longitudinal and transverse polarization of the daughter baryon Λ+c and the τ lepton, and the lepton-side forward-backward asymmetries. The nonvanishing polarization of the daughter baryon Λ+c leads to hadron-side asymmetries in e.g. the decay Λ+c→Λ0+π+ 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

Physical observables in the decay Λb→Λc(→Λ+π)+τ−+ν̄τ

We analyze the tauonic semileptonic baryon decays Λ0b→Λ+c+τ−+ν̄ 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