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

TL;DR

This paper extracts the CKM matrix elements |V_{ub}| and |V_{cb}| using exclusive Lambda_b decays, providing results that align with some previous measurements and offer insights into flavor physics.

Contribution

It presents a novel simultaneous extraction of |V_{ub}| and |V_{cb}| solely from Lambda_b decay channels, improving precision and consistency with other decay-based determinations.

Findings

|V_{ub}| = (3.7 ± 0.3)×10^{-3}

|V_{cb}| = (45.9 ± 2.7)×10^{-3}

Results favor certain inclusive and exclusive decay measurements.

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.