Volume 352 - XXVII International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2019) - Joint Working Group 3 + Working Group 5: Higgs and BSM + HF Physics
Search for new physics in CP violation with beauty and charm decays at LHCb
M. Bartolini* on behalf of the LHCb collaboration
*corresponding author
Full text: pdf
Pre-published on: 2019 June 28
Published on:
Abstract
LHCb is one of the four big experiments operating at LHC and it's mainly dedicated
to measurements of $C\!P$ violation and to the search for new physics in the decays of
rare hadrons containing heavy quarks. The LHCb collaboration has recently published a result which shows for the first time a compelling 5.3 $\sigma$ evidence of $C\!P$ violation in the two-body meson $D^{0}\rightarrow K^{+}K^{-}$ and $D^{0}\rightarrow \pi^{+}\pi^{-}$ decays.
$C\!P$ violation in the Cabibbo-suppressed decays $D^{+}_{s} \rightarrow K^{0}_{S}\pi^{+}$, $D^{+} \rightarrow K^{0}_{S}K^{+}$, $D^{+} \rightarrow \phi \pi^{+}$ is expected to be small ($\sim10^{-3}$) due to interference between tree and penguin diagrams and thus sensible to contributions Beyond Standard Model (BSM). The last measurement by LHCb of direct $C\!P$ asymmetries in the
aforementioned decay channels shows consistency with the hypothesis of $C\!P$ conservation.
In the $B_{s}$ sector the $C\!P$ violating phase $\phi_{s}$ receives contributions from direct decay and mixing and may also be sensitive to BSM contributions. The last two published
measurements of $\phi_{s}$ using the $B_{s}\rightarrow J/\psi K^{+}K^{-}$ and $B_{s}\rightarrow J/\psi \pi^{+} \pi^{-}$ decay channels show a combined 2 $\sigma$ hint of $C\!P$ violation.
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