Publication Date:
2021-06-01
Description:
Searches for CP violation in the two-body decays $$ {D}_{(s)}^{+}o {h}^{+}{pi}^0 $$ D s + → h + π 0 and $$ {D}_{(s)}^{+}o {h}^{+}eta $$ D s + → h + η (where h+ denotes a π+ 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 π0 and η mesons are reconstructed using the e+e−γ final state, which can proceed as three-body decays π0→ e+e−γ and η → e+e−γ, or via the two-body decays π0→ γγ and η → γγ followed by a photon conversion. The measurements are made relative to the control modes $$ {D}_{(s)}^{+}o {K}_{mathrm{S}}^0{h}^{+} $$ D s + → K S 0 h + to cancel the production and detection asymmetries. The CP asymmetries are measured to be$$ {displaystyle egin{array}{c}{mathcal{A}}_{CP}left({D}^{+}o {pi}^{+}{pi}^0
ight)=left(-1.3pm 0.9pm 0.6
ight)\%, {}{mathcal{A}}_{CP}left({D}^{+}o {K}^{+}{pi}^0
ight)=left(-3.2pm 4.7pm 2.1
ight)\%, {} egin{array}{c}{mathcal{A}}_{CP}left({D}^{+}o {pi}^{+}eta
ight)=left(-0.2pm 0.8pm 0.4
ight)\%, {}{mathcal{A}}_{CP}left({D}^{+}o {K}^{+}eta
ight)=left(-6pm 10pm 4
ight)\%, {} egin{array}{c}{mathcal{A}}_{CP}left({D}_s^{+}o {K}^{+}{pi}^0
ight)=left(-0.8pm 3.9pm 1.2
ight)\%, {} egin{array}{c}{mathcal{A}}_{CP}left({D}_s^{+}o {pi}^{+}eta
ight)=left(0.8pm 0.7pm 0.5
ight)\%, {}{mathcal{A}}_{CP}left({D}_s^{+}o {K}^{+}eta
ight)=left(0.9pm 3.7pm 1.1
ight)\%,end{array}end{array}end{array}end{array}} $$ A CP D + → π + π 0 = − 1.3 ± 0.9 ± 0.6 % , A CP D + → K + π 0 = − 3.2 ± 4.7 ± 2.1 % , A CP D + → π + η = − 0.2 ± 0.8 ± 0.4 % , A CP D + → K + η = − 6 ± 10 ± 4 % , A CP D s + → K + π 0 = − 0.8 ± 3.9 ± 1.2 % , A CP D s + → π + η = 0.8 ± 0.7 ± 0.5 % , A CP D s + → K + η = 0.9 ± 3.7 ± 1.1 % , 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 $$ {mathcal{A}}_{CP} $$ A CP in these decay modes to date.
Print ISSN:
1126-6708
Electronic ISSN:
1029-8479
Topics:
Physics
Permalink