Journal of High Energy Physics (Jul 2018)
On the angular distribution of Λ b → Λ(→ N π)τ +τ − decay
Abstract
Abstract We present a full angular distribution of the four body Λ b → Λ(→ N π)ℓ+ℓ− decay where the leptons are massive and the Λ b is unpolarized, in an operator basis which includes the Standard Model operators, new vector and axial-vector operators, and scalar and pseudo-scalar operators. The angular coefficients are expressed in terms of transversity amplitudes. We study several Λ b → Λ(→ pπ)τ +τ − observables in the Standard Model and in the presence of the new operators. For our numerical analysis, we use the form factors from lattice QCD calculations.
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