Study of CP violation in BKπ+π and BKσ(600) decays in the QCD factorization approach

Qi, Jing-Juan (College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China) ; Guo, Xin-Heng (College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China) ; Wang, Zhen-Yang (Physics Department, Ningbo University, Zhejiang 315211, China) ; Zhang, Zhen-Hua (School of Nuclear and Technology, University of South China, Hengyang, Hunan 421001, China) ; Wang, Chao (Center for Ecological and Environmental Sciences, Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi’an 710072, China)

16 April 2019

Abstract: In this work, we study the localized CP violation in BKπ+π and BKσ(600) decays by employing the quasi-two-body QCD factorization approach. Both the resonance and the nonresonance contributions are studied for the BKπ+π decay. The resonance contributions include those not only from [ππ] channels including σ(600), ρ0(770) and ω(782) but also from [Kπ] channels including K0*(700)(κ), K*(892), K0*(1430), K*(1410), K*(1680) and K2*(1430). By fitting the four experimental data ACP(Kπ+π)=0.678±0.078±0.0323±0.007 for mKπ+2<15 GeV2 and 0.08<mπ+π2<0.66 GeV2, ACP(BK0*(1430)π)=0.061±0.032, B(BK0*(1430)π)=(395+6)×106 and B(Bσ(600)πππ+π)<4.1×106, we get the end-point divergence parameters in our model, ϕS[1.77,2.25] and ρS[2.39,4.02]. Using these results for ρS and ϕS, we predict that the CP asymmetry parameter ACP[0.34,0.11] and the branching fraction B[6.53,17.52]×106 for the BKσ(600) decay. In addition, we also analyze contributions to the localized CP asymmetry ACP(BKπ+π) from [ππ], [Kπ] channel resonances and nonresonance individually, which are found to be ACP(BK[π+π]Kπ+π)=0.509±0.042, ACP(B[Kπ+]πKπ+π)=0.174±0.025 and ACPNR(BKπ+π)=0.061±0.0042, respectively. Comparing these results, we can see that the localized CP asymmetry in the BKπ+π decay is mainly induced by the [ππ] channel resonances while contributions from the [Kπ] channel resonances and nonresonance are both very small.

Published in: Physical Review D 99 (2019)
Published by: APS
DOI: 10.1103/PhysRevD.99.076010
License: CC-BY-4.0

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