Measurement of the CKM angle γ and B s 0 ‐ B ¯ s 0 $$ {B}_s^0\hbox{-} {\overline{B}}_s^0 $$ mixing frequency with B s 0 → D s ∓ h ± π ± π ∓ $$ {B}_s^0\to {D}_s^{\mp }{h}^{\pm }{\pi}^{\pm }{\pi}^{\mp } $$ decays
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13130_2021_Article_15094.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
March 15, 2021
Publisher
Springer Berlin Heidelberg
Citation
Journal of High Energy Physics. 2021 Mar 15;2021(3):137
Version
Final published version
Abstract
Abstract
The CKM angle γ is measured for the first time from mixing-induced CP violation between
B
s
0
→
D
s
∓
K
±
π
±
π
∓
$$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm }{\pi}^{\pm }{\pi}^{\mp } $$
and
B
¯
s
0
→
D
s
±
K
∓
π
∓
π
±
$$ {\overline{B}}_s^0\to {D}_s^{\pm }{K}^{\mp }{\pi}^{\mp }{\pi}^{\pm } $$
decays reconstructed in proton-proton collision data corresponding to an integrated luminosity of 9 fb−1 recorded with the LHCb detector. A time-dependent amplitude analysis is performed to extract the CP-violating weak phase γ − 2βs and, subsequently, γ by taking the
B
s
0
‐
B
¯
s
0
$$ {B}_s^0\hbox{-} {\overline{B}}_s^0 $$
mixing phase βs as an external input. The measurement yields γ = (44 ± 12)° modulo 180°, where statistical and systematic uncertainties are combined. An alternative model-independent measurement, integrating over the five-dimensional phase space of the decay, yields
γ
=
44
−
13
+
20
°
$$ \gamma =\left({44}_{-13}^{+20}\right){}^{\circ} $$
modulo 180°. Moreover, the
B
s
0
‐
B
¯
s
0
$$ {B}_s^0\hbox{-} {\overline{B}}_s^0 $$
oscillation frequency is measured from the flavour-specific control channel
B
s
0
→
D
s
−
π
+
π
+
π
−
$$ {B}_s^0\to {D}_s^{-}{\pi}^{+}{\pi}^{+}{\pi}^{-} $$
to be ∆ms = (17.757 ± 0.007(stat) ± 0.008(syst)) ps−1, consistent with and more precise than the current world-average value.
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/JHEP03(2021)137
