Simultaneous extractions of $|V_{ub}|$ and $|V_{cb}|$ with only the exclusive ${\Lambda }_b$ decays

Abstract

We perform the simultaneous $|V_{ub}|$ and $|V_{cb}|$ extractions with only the exclusive ${\Lambda }_b$ decays of ${\Lambda }_b\to (p,{\Lambda }_c^{+})\mu {\bar{\nu }}_{\mu }$, ${\Lambda }_b\to p{\pi }^{-}$ and ${\Lambda }_b\to {\Lambda }_c^{+}({\pi }^{-},D^{-})$. We obtain that $|V_{ub}|=(3.7\pm 0.3)\times 10^{-3}$ and $|V_{cb}|=(45.9\pm 2.7)\times 10^{-3}$. Our value of $|V_{ub}|$ is larger than that of $(3.27\pm 0.15\pm 0.16\pm 0.06)\times 10^{-3}$, previously extracted by the LHC Collaboration from the exclusive ${\Lambda }_b$ decays also, but nearly identical to $(3.72\pm 0.19)\times 10^{-3}$ from the exclusive $B$ decays. On the other hand, our extracted result of $|V_{cb}|$ favors the value of $(42.2\pm 0.8)\times 10^{-3}$ from the inclusive $B$ decays.

Comments: 10 pages, 1 figure, accepted for publication in PLB