Determinations of $$|V_{cb}|$$ |Vcb| and $$|V_{ub}|$$ |Vub| from baryonic $$\Lambda _b$$ Λb decays

Abstract

Abstract We present the first attempt to extract $$|V_{cb}|$$ |Vcb| from the $$\Lambda _b\rightarrow \Lambda _c^+\ell \bar{\nu }_\ell $$ Λb→Λc+ℓν¯ℓ decay without relying on $$|V_{ub}|$$ |Vub| inputs from the B meson decays. Meanwhile, the hadronic $$\Lambda _b\rightarrow \Lambda _c M_{(c)}$$ Λb→ΛcM(c) decays with $$M=(\pi ^-,K^-)$$ M=(π-,K-) and $$M_c=(D^-,D^-_s)$$ Mc=(D-,Ds-) measured with high precisions are involved in the extraction. Explicitly, we find that $$|V_{cb}|=(44.6\pm 3.2)\times 10^{-3}$$ |Vcb|=(44.6±3.2)×10-3 , agreeing with the value of $$(42.11\pm 0.74)\times 10^{-3}$$ (42.11±0.74)×10-3 from the inclusive $$B\rightarrow X_c\ell \bar{\nu }_\ell $$ B→Xcℓν¯ℓ decays. Furthermore, based on the most recent ratio of $$|V_{ub}|/|V_{cb}|$$ |Vub|/|Vcb| from the exclusive modes, we obtain $$|V_{ub}|=(4.3\pm 0.4)\times 10^{-3}$$ |Vub|=(4.3±0.4)×10-3 , which is close to the value of $$(4.49\pm 0.24)\times 10^{-3}$$ (4.49±0.24)×10-3 from the inclusive $$B\rightarrow X_u\ell \bar{\nu }_\ell $$ B→Xuℓν¯ℓ decays. We conclude that our determinations of $$|V_{cb}|$$ |Vcb| and $$|V_{ub}|$$ |Vub| favor the corresponding inclusive extractions in the B decays.