The decays ${\Lambda }_{b,c}\to N^{\ast }l\nu$ in QCD

Abstract

We present an exploratory study of the ${\Lambda }_{c,b}\to N^{\ast }$-form factors and the semileptonic decay width within the framework of light-cone sum rules. We use two different methods and two different interpolating currents for the ${\Lambda }_{c,b}$. As interpolating currents we choose an axial-vector like and a pseudoscalar like current. Our results show that the procedure of eliminating negative parity partners is not well suited for the case at hand and that the second approach using structures with highest powers of $p_{+}$ with an axial-vector like interpolating current gives the most reliable results. Our predictions are based on the models obtained in \cite{Anikin:2015ita,Braun:2014wpa}. The largest uncertainty comes from the uncertainty of the twist 4 parameters ${\eta }_{10},{\eta }_{11}$ and we take the spread between the two models in \cite{Anikin:2015ita} as a measure for this. We get \begin{eqnarray} Γ(Λ_b\to N^*(1535) l ν)&=&\left(0.0058^{+0.0010}_{-0.0009}\right)\cdot\left(\dfrac{V_{ub}}{3.5\cdot10^{-3}}\right)^2,\quad\mbox{LCSR(1)} \nonumber Γ(Λ_b\to N^*(1535) l ν)&=&\left(0.00070^{+0.00012}_{-0.00011}\right)\cdot\left(\dfrac{V_{ub}}{3.5\cdot10^{-3}}\right)^2,\quad\mbox{LCSR(2)} \nonumber Γ(Λ_c\to N^*(1535) l ν)&=&\left(0.0064^{+0.0012}_{-0.0011}\right)\cdot \left(\dfrac{V_{cd}}{0.225}\right)^2,\quad\mbox{LCSR(1)}\nonumber Γ(Λ_c\to N^*(1535) l ν)&=&\left(0.00077^{+0.00016}_{-0.00014}\right)\cdot \left(\dfrac{V_{cd}}{0.225}\right)^2,\quad\mbox{LCSR(2)}\nonumber \end{eqnarray} as predictions for the respective decay widths, where LCSR(1) and LCSR(2) refer to the two different models of the distribution amplitudes of the $N^{\ast }$. It is seen that even a rough measurement of these decays will greatly help to discriminate different models.

15 pages, 6 figures

References in corpus (6)

• Weak decays of heavy hadrons into dynamically generated resonances
• ${\Lambda }_b\to p,\Lambda$ transition form factors from QCD light-cone sum rules
• Light-cone Distribution Amplitudes of the Nucleon and Negative Parity Nucleon Resonances from Lattice QCD
• Electroproduction of the N*(1535) resonance at large momentum transfer
• Updates on the Studies of $N^{\ast }$ Structure with CLAS and the Prospects with CLAS12
• Baryon octet distribution amplitudes in Wandzura-Wilczek approximation

Cited by in corpus (5)

• ${\Lambda }_c$ semileptonic decays
• Analysis of the semileptonic decay Λ_c->ne^+ν_e
• ${\Lambda }_b\to p,N^{\ast }(1535)$ Form Factors from QCD Light-Cone Sum Rules
• $N^{\ast }(1535)\to N$ transition form-factors due to the axial current
• Study of the ${\Lambda }_b\to N^{\ast }{\ell }^{+}{\ell }^{-}$ decay in light cone sum rules