Measurement of the polarizations of prompt and non-prompt And Mesons Produced in pp Collisions at

The polarizations of prompt and non-prompt Image 2 and $\psi \left(2S\right)$ mesons are measured in proton-proton collisions at $\sqrt{s}=13$ TeV, using data samples collected by the CMS experiment in 2017 and 2018, corresponding to a total integrated luminosity of 103.3$\phantom{\rule{0.2em}{0ex}}{\text{fb}}^{-1}$. Based on the analysis of the dimuon decay angular distributions in the helicity frame, the polar anisotropy, ${\lambda }_{\vartheta }$, is measured as a function of the transverse momentum, ${p}_{T}$, of the charmonium states, in the 25–120 and 20–100 GeV ranges for the Image 2 and $\psi \left(2S\right)$, respectively. The non-prompt polarizations agree with predictions based on the hypothesis that, for ${p}_{T}\gtrsim 25\phantom{\rule{0.2em}{0ex}}\text{GeV}$, the non-prompt Image 2 and $\psi \left(2S\right)$ are predominantly produced in two-body B meson decays. The prompt results clearly exclude strong transverse polarizations, even for ${p}_{T}$ exceeding 30 times the Image 2 mass, where ${\lambda }_{\vartheta }$ tends to an asymptotic value around 0.3. Taken together with previous measurements, by CMS and LHCb at $\sqrt{s}=7$ TeV, the prompt polarizations show a significant variation with ${p}_{T}$, at low ${p}_{T}$.