Angular distributions for multi-body semileptonic charmed baryon decays

Abstract

Abstract We perform an analysis of angular distributions in semileptonic decays of charmed baryons $$B_1^{(\prime )}\rightarrow B_2^{(\prime )}(\rightarrow B_3^{(\prime )}B_4^{(\prime )})\ell ^+\nu _{\ell }$$ B 1 ( ′ ) → B 2 ( ′ ) ( → B 3 ( ′ ) B 4 ( ′ ) ) ℓ + ν ℓ , where the $$B_1{=}(\Lambda _c^+,\Xi _c^{(0,+)})$$ B 1 = ( Λ c + , Ξ c ( 0 , + ) ) are the SU(3)-antitriplet baryons and $$B_1'{=}\Omega _c^-$$ B 1 ′ = Ω c - is an SU(3) sextet. We will firstly derive analytic expressions for angular distributions using the helicity amplitude technique. Based on the lattice quantum chromodynamics (QCD) results for $$\Lambda _c^+\rightarrow \Lambda $$ Λ c + → Λ and $$\Xi _c^0\rightarrow \Xi ^-$$ Ξ c 0 → Ξ - form factors and model calculation of the $$\Omega _c^0\rightarrow \Omega ^-$$ Ω c 0 → Ω - transition, we predict the branching fractions: $${\mathcal {B}}(\Lambda _{c}^{+} \rightarrow \Lambda (\rightarrow p \pi ^{-}) e^{+} \nu _{e})=2.48(15)\%$$ B ( Λ c + → Λ ( → p π - ) e + ν e ) = 2.48 ( 15 ) % , $${\mathcal {B}}(\Lambda _{c}^+\rightarrow \Lambda (\rightarrow p \pi ^{-})\mu ^{+}\nu _{\mu })=2.50(14)\%$$ B ( Λ c + → Λ ( → p π - ) μ + ν μ ) = 2.50 ( 14 ) % , $${\mathcal {B}}(\Xi _{c}^0\rightarrow \Xi ^-(\rightarrow \Lambda \pi ^{-})e^{+}\nu _{e})=2.40(30)\%$$ B ( Ξ c 0 → Ξ - ( → Λ π - ) e + ν e ) = 2.40 ( 30 ) % , $${\mathcal {B}}(\Xi _{c}^0\rightarrow \Xi ^-(\rightarrow \Lambda \pi ^{-})\mu ^{+}\nu _{\nu })=2.41(30)\%$$ B ( Ξ c 0 → Ξ - ( → Λ π - ) μ + ν ν ) = 2.41 ( 30 ) % , $${\mathcal {B}}(\Omega _{c}^0\rightarrow \Omega ^-(\rightarrow \Lambda K^{-})e^{+}\nu _{e})=\!0.362(14)\%$$ B ( Ω c 0 → Ω - ( → Λ K - ) e + ν e ) = 0.362 ( 14 ) % , $${\mathcal {B}}(\Omega _{c}^0\rightarrow \Omega ^-\!(\rightarrow \Lambda K^{-})\mu ^{+\!}\nu _{\nu })=0.350(14)\%$$ B ( Ω c 0 → Ω - ( → Λ K - ) μ + ν ν ) = 0.350 ( 14 ) % . We also predict the $$q^2$$ q 2 dependence and angular distributions of these processes, in particular the coefficients for the $$\cos n\theta _{\ell }$$ cos n θ ℓ ( $$\cos n\theta _{h}$$ cos n θ h , $$\cos n\phi $$ cos n ϕ ) $$(n=0, 1, 2, \ldots )$$ ( n = 0 , 1 , 2 , … ) terms. This work can provide a theoretical basis for the ongoing experiments at BESIII, LHCb, and BELLE-II.