Measurement of ψ(2S) polarisation in pp collisions at √s = 7 TeV: see text] polarisation in [Formula: see text] collisions at [Formula: see text] = 7 TeV

The polarisation of prompt ψ(2S) mesons is measured by performing an angular analysis of ψ(2S) → μ ⁺μ _- decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 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 _T and rapidity y in the kinematic region 3.5 < p _T < 15 GeV/c and 2.0 < y < 4.5, and is compared to theoretical models. No significant polarisation is observed.