Measurement of CP violation in the <i>B<sub>s</sub></i><SUP>0</SUP>→ φφ decay and search for the <i>B</i><SUP>0</SUP><i>→</i> φφ decay

Aaij, R, Beteta, C Abellan, Adeva, B, Adinol, M, Aidala, CA, Ajaltouni, Z, Akar, S, Albicocco, P, Albrecht, J, Alessio, F
et al (show 860 more authors) (2019) Measurement of CP violation in the <i>B<sub>s</sub></i><SUP>0</SUP>→ φφ decay and search for the <i>B</i><SUP>0</SUP><i>→</i> φφ decay. JOURNAL OF HIGH ENERGY PHYSICS, 2019 (12). 155-.

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<jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>A measurement of the time-dependent CP-violating asymmetry in <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ {B}_s^0\to \phi \phi $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mo>→</mml:mo> <mml:mi>ϕϕ</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> decays is presented. Using a sample of proton-proton collision data corresponding to an integrated luminosity of 5<jats:italic>.</jats:italic>0 fb<jats:sup> <jats:italic>−</jats:italic>1</jats:sup> collected by the LHCb experiment at centre-of-mass energies <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s} $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> </jats:alternatives> </jats:inline-formula> = 7 TeV in 2011, 8 TeV in 2012 and 13 TeV in 2015 and 2016, a signal yield of around 9000 <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ {B}_s^0\to \phi \phi $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:mo>→</mml:mo> <mml:mi>ϕϕ</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> decays is obtained. The CP-violating phase <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ {\phi}_s^{s\overline{s}s} $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:msubsup> <mml:mi>ϕ</mml:mi> <mml:mi>s</mml:mi> <mml:mrow> <mml:mi>s</mml:mi> <mml:mover> <mml:mi>s</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>s</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> </jats:alternatives> </jats:inline-formula> is measured to be <jats:italic>−</jats:italic>0<jats:italic>.</jats:italic>073 ± 0<jats:italic>.</jats:italic>115(stat) ± 0<jats:italic>.</jats:italic>027(syst) rad, under the assumption it is independent of the helicity of the <jats:italic>ϕϕ</jats:italic> decay. In addition, the CP-violating phases of the transverse polarisations under the assumption of CP conservation of the longitudinal phase are measured. The helicity-independent direct CP-violation parameter is also measured, and is found to be |λ| = 0<jats:italic>.</jats:italic>99 ± 0<jats:italic>.</jats:italic>05(stat) ± 0<jats:italic>.</jats:italic>01(syst). In addition, <jats:italic>T</jats:italic>-odd triple-product asymmetries are measured. The results obtained are consistent with the hypothesis of CP conservation in <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \overline{b}\to \overline{s}s\overline{s}s $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:mover> <mml:mi>s</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>s</mml:mi> <mml:mover> <mml:mi>s</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>s</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> transitions. Finally, a limit on the branching fraction of the <jats:italic>B</jats:italic> <jats:sup>0</jats:sup> → <jats:italic>ϕϕ</jats:italic> decay is determined to be <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathcal{B}\left({B}^0\to \phi \phi \right)&lt;2.7\times {10}^{-8} $$</jats:tex-math> <mml:math xmlns:mml=""> <mml:mi>B</mml:mi> <mml:mfenced> <mml:mrow> <mml:msup> <mml:mi>B</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>→</mml:mo> <mml:mi>ϕϕ</mml:mi> </mml:mrow> </mml:mfenced> <mml:mo>&lt;</mml:mo> <mml:mn>2.7</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> </mml:msup> </mml:math> </jats:alternatives> </jats:inline-formula> at 90 % confidence level.</jats:p>

Item Type: Article
Uncontrolled Keywords: Hadron-Hadron scattering (experiments)
Depositing User: Symplectic Admin
Date Deposited: 05 Feb 2020 11:08
Last Modified: 14 Mar 2024 23:19
DOI: 10.1007/JHEP12(2019)155
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