Search for <i>CP</i> violation in <i>D</i><sub>(<i>s</i>)</sub><SUP>+</SUP> → <i>h</i><SUP>+</SUP> π<SUP>0</SUP> and decays <i>D</i><sub>(<i>s</i>)</sub><SUP>+</SUP> → <i>h</i><SUP>+</SUP> η decays



Aaij, R, Beteta, C Abellan, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 945 more authors) (2021) Search for <i>CP</i> violation in <i>D</i><sub>(<i>s</i>)</sub><SUP>+</SUP> → <i>h</i><SUP>+</SUP> π<SUP>0</SUP> and decays <i>D</i><sub>(<i>s</i>)</sub><SUP>+</SUP> → <i>h</i><SUP>+</SUP> η decays. JOURNAL OF HIGH ENERGY PHYSICS, 06 (6). 019-.

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Abstract

Searches for $CP$ violation in the two-body decays $D_{(s)}^{+}\rightarrow h^{+}\pi^{0}$ and $D_{(s)}^{+} \rightarrow h^{+}\eta$ (where $h^{+}$ denotes a $\pi^{+}$ or $K^{+}$ meson) are performed using $pp$ collision data collected by the LHCb experiment corresponding to either 9 fb$^{-1}$ or 6 fb$^{-1}$ of integrated luminosity. The $\pi^{0}$ and $\eta$ mesons are reconstructed using the $e^{+}e^{-}\gamma$ final state, which can proceed as three-body decays $\pi^{0}\rightarrow e^{+}e^{-}\gamma$ and $\eta \rightarrow e^{+}e^{-}\gamma$, or via the two-body decays $\pi^{0}\rightarrow \gamma\gamma$ and $\eta\rightarrow\gamma\gamma$ followed by a photon conversion. The measurements are made relative to the control modes $D_{(s)}^{+}\rightarrow K_{S}^{0} h^{+}$ to cancel the production and detection asymmetries. The $CP$ asymmetries are measured to be \begin{align} \mathcal{A}_{CP}(D^{+}\rightarrow \pi^{+}\pi^{0}) &= (-1.3 \pm 0.9 \pm 0.6 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D^{+}\rightarrow K^{+}\pi^{0}) &= (-3.2 \pm 4.7 \pm 2.1 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D^{+}\rightarrow \pi^{+}\eta) &= (-0.2 \pm 0.8 \pm 0.4 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D^{+}\rightarrow K^{+}\eta) &= (-6 \pm 10 \pm 4 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D_{s}^{+}\rightarrow K^{+}\pi^{0}) &= (-0.8 \pm 3.9 \pm 1.2 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D_{s}^{+}\rightarrow \pi^{+}\eta) &= (0.8 \pm 0.7 \pm 0.5 )\%, \end{align} \begin{align} \mathcal{A}_{CP}(D_{s}^{+}\rightarrow K^{+}\eta) &= (0.9 \pm 3.7 \pm 1.1 )\%, \end{align} where the first uncertainties are statistical and the second systematic. These results are consistent with no $CP$ violation and mostly constitute the most precise measurements of $\mathcal{A}_{CP}$ in these decay modes to date.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-001.html (LHCb public pages)
Uncontrolled Keywords: Charm physics, CP violation, Hadron-Hadron scattering (experiments)
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 Sep 2021 09:05
Last Modified: 14 Mar 2024 23:01
DOI: 10.1007/JHEP06(2021)019
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3134981