Measurement of $CP$ violation in $B^0 \to K_S^0 \pi^0$ decays at Belle II

Abstract We report a measurement of the $C\!P$-violating parameters $A$ and $S$ in $B^{0}\to K_{S}^{0} π^{0}$ decays at Belle II using a sample of $387\times 10^{6}$$B\bar{B}$ events recorded in $e^{+}e^{-}$ collisions at a center-of-mass energy corresponding to the $Υ(4S)$ resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain $A = 0.04^{+0.15}_{-0.14}\pm 0.05$ and $S = 0.75^{+0.20}_{-0.23}\pm 0.04$, where the first uncertainties are statistical and the second are systematic.
Tags
Working group Time Dependent CP Violation
Principal authors @  Sagar Hazra, Abdul Kaliyar, Gagan Mohanty
Reference Phys.Rev.Lett. 131, 111803 (2023), DOI: 10.1103/PhysRevLett.131.111803
Document BELLE2-PUB-PH-2023-025
Links arXiv:2305.07555, Inspire, PRL
Bibtex 
@article{Belle-II:2023grc,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Measurement of CP Violation in B0{\textrightarrow}KS0{\ensuremath{\pi}}0 Decays at Belle II}",
    eprint = "2305.07555",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II Preprint 2023-006, KEK Preprint 2023-2",
    doi = "10.1103/PhysRevLett.131.111803",
    journal = "Phys. Rev. Lett.",
    volume = "131",
    number = "11",
    pages = "111803",
    year = "2023"
}