Direct CP violation in internal W-emission dominated baryonic B decays

Y. K. Hsiao; Shang-Yuu Tsai; Eduardo Rodrigues

doi:10.1140/epjc/s10052-020-8134-0

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2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2020) 80: 565
https://doi.org/10.1140/epjc/s10052-020-8134-0

Regular Article - Theoretical Physics

Direct CP violation in internal W-emission dominated baryonic B decays

Y. K. Hsiao¹, Shang-Yuu Tsai¹^* and Eduardo Rodrigues²

¹ School of Physics and Information Engineering, Shanxi Normal University, Linfen, 041004, China
² Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK

^* e-mail: shangyuu@gmail.com

Received: 14 March 2020
Accepted: 9 June 2020
Published online: 23 June 2020

Abstract

The observation of CP violation has been experimentally verified in numerous B decays but is yet to be confirmed in final states with half-spin particles. We focus our attention on baryonic B-meson decays mediated dominantly through internal W-emission processes and show that they are promising processes to observe for the first time the CP violating effects in B decays to final states with half-spin particles. Specifically, we study the $\bar{B}^0\rightarrow p\bar{p}\pi ^0(\rho ^0)$ and $\bar{B}^0\rightarrow p\bar{p}\pi ^+\pi ^-$ decays. We obtain $\mathcal{B}(\bar{B}^0\rightarrow p\bar{p}\pi ^0)=(5.0\pm 2.1)\times 10^{-7}$ , in agreement with current data, and $\mathcal{B}(\bar{B}^0\rightarrow p\bar{p}\rho ^0)\simeq \mathcal{B}(\bar{B}^0\rightarrow p\bar{p}\pi ^0)/3$ . Furthermore, we find $\mathcal{A}_{CP}(\bar{B}^0\rightarrow p\bar{p}\pi ^0,p\bar{p}\rho ^0,p\bar{p}\pi ^+\pi ^-) =(-16.8\pm 5.4,-12.6\pm 3.0,-11.4\pm 1.9)\%$ . With measured branching fractions $\mathcal{B}(\bar{B}^0\rightarrow p\bar{p}\pi ^0,p\bar{p}\pi ^+\pi ^-)\sim \mathcal{O}(10^{-6})$ , we point out that $\mathcal{A}_{CP}\sim -(10-20)\%$ can be new observables for CP violation, accessible to the Belle II and/or LHCb experiments.