English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The time-dependent $CP$ asymmetry in $B_s^0 \to J/\psi K^+K^-$ decays ismeasured using $pp$ collision data, corresponding to an integrated luminosityof $3.0$fb$^{-1}$, collected with the LHCb detector at centre-of-mass energiesof $7$ and $8$TeV. In a sample of 96 000 $B_s^0 \to J/\psi K^+K^-$ decays, the$CP$-violating phase $\phi_s$ is measured, as well as the decay widths$\Gamma_{L}$ and $\Gamma_{H}$ of the light and heavy mass eigenstates of the$B_s^0-\bar{B}_s^0$ system. The values obtained are $\phi_s = -0.058 \pm 0.049\pm 0.006$ rad, $\Gamma_s \equiv (\Gamma_{L}+\Gamma_{H})/2 = 0.6603 \pm 0.0027\pm 0.0015$ps$^{-1}$, and$\Delta\Gamma_s \equiv \Gamma_{L} - \Gamma_{H} =0.0805 \pm 0.0091 \pm 0.0032$ps$^{-1}$, where the first uncertainty isstatistical and the second systematic. These are the most precise singlemeasurements of those quantities to date. A combined analysis with $B_s^{0} \toJ/\psi \pi^+\pi^-$ decays gives $\phi_s = -0.010 \pm 0.039 $rad. Allmeasurements are in agreement with the Standard Model predictions. For thefirst time the phase $\phi_s$ is measured independently for each polarisationstate of the $K^+K^- $ system and shows no evidence for polarisationdependence.

Precision measurement of $CP$ violation in $B_s^0 \to J/\psi K^+K^-$ decays