Search for CP violation in D s + → h + π 0 $$ {D}_{(s)}^{+}\to {h}^{+}{\pi}^0 $$ and D s + → h + η $$ {D}_{(s)}^{+}\to {h}^{+}\eta $$ decays
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13130_2021_Article_15874.pdf
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Author(s)
Aaij, R.
Abellán Beteta, C.
Ackernley, T.
Adeva, B.
Adinolfi, M.
Afsharnia, H.
Aidala, C. A.
Aiola, S.
Ajaltouni, Z.
Akar, S.
Date Issued
June 3, 2021
Publisher
Springer Berlin Heidelberg
Citation
Journal of High Energy Physics. 2021 Jun 03;2021(6):19
Version
Final published version
Abstract
Abstract
Searches for CP violation in the two-body decays
D
s
+
→
h
+
π
0
$$ {D}_{(s)}^{+}\to {h}^{+}{\pi}^0 $$
and
D
s
+
→
h
+
η
$$ {D}_{(s)}^{+}\to {h}^{+}\eta $$
(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
+
→
K
S
0
h
+
$$ {D}_{(s)}^{+}\to {K}_{\mathrm{S}}^0{h}^{+} $$
to cancel the production and detection asymmetries. The CP asymmetries are measured to be
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
%
,
$$ {\displaystyle \begin{array}{c}{\mathcal{A}}_{CP}\left({D}^{+}\to {\pi}^{+}{\pi}^0\right)=\left(-1.3\pm 0.9\pm 0.6\right)\%,\\ {}{\mathcal{A}}_{CP}\left({D}^{+}\to {K}^{+}{\pi}^0\right)=\left(-3.2\pm 4.7\pm 2.1\right)\%,\\ {}\begin{array}{c}{\mathcal{A}}_{CP}\left({D}^{+}\to {\pi}^{+}\eta \right)=\left(-0.2\pm 0.8\pm 0.4\right)\%,\\ {}{\mathcal{A}}_{CP}\left({D}^{+}\to {K}^{+}\eta \right)=\left(-6\pm 10\pm 4\right)\%,\\ {}\begin{array}{c}{\mathcal{A}}_{CP}\left({D}_s^{+}\to {K}^{+}{\pi}^0\right)=\left(-0.8\pm 3.9\pm 1.2\right)\%,\\ {}\begin{array}{c}{\mathcal{A}}_{CP}\left({D}_s^{+}\to {\pi}^{+}\eta \right)=\left(0.8\pm 0.7\pm 0.5\right)\%,\\ {}{\mathcal{A}}_{CP}\left({D}_s^{+}\to {K}^{+}\eta \right)=\left(0.9\pm 3.7\pm 1.1\right)\%,\end{array}\end{array}\end{array}\end{array}} $$
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
A
CP
$$ {\mathcal{A}}_{CP} $$
in these decay modes to date.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.1007/JHEP06(2021)019
