Measurement of $$\psi {(2S)} $$ polarisation in $$pp$$pp collisions at $$\sqrt{s}$$s = 7 TeV

The polarisation of prompt \(\psi {(2S)} \) mesons is measured by performing an angular analysis of \(\psi {(2S)} \!\rightarrow \mu ^+\mu ^- \) decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0\(\,\text{ fb }^{-1} \), collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum \(p_\mathrm{T} \) and rapidity \(y\) in the kinematic region \(3.5< p_\mathrm{T} <15{\mathrm {\,GeV\!/}c} \) and \(2.0更多