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Search for new physics in CP violation with beauty and charm decays at LHCb

LHCb is one of the four big experiments operating at LHC and it's mainly dedicatedto measurements of $C\!P$ violation and to the search for new physics in the decays ofrare hadrons containing heavy quarks. The LHCb collaboration has recently published a result which shows for the first time a c...

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Detalles Bibliográficos
Autor principal: Bartolini, Matteo
Lenguaje:eng
Publicado: SISSA 2019
Materias:
Acceso en línea:https://dx.doi.org/10.22323/1.352.0250
http://cds.cern.ch/record/2693739
Descripción
Sumario:LHCb is one of the four big experiments operating at LHC and it's mainly dedicatedto measurements of $C\!P$ violation and to the search for new physics in the decays ofrare 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 theaforementioned 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 publishedmeasurements 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.