Multiplicity dependence of K^∗(892)^± production in pp collisions at √𝑠 = 13 TeV

The first results of K*(892)(+/-) production at midrapidity (|y| < 0.5) in pp collisions at root s = 13 TeV as a function of the event multiplicity are presented. The K*(892)+/- has been reconstructed via its hadronic decay channel K*(892)(+/-) -> pi +/- + K-S(0) using the ALICE detector at the LHC. For each multiplicity class, the differential transverse momentum (p(T)) spectrum, the mean transverse momentum < p(T)>, the p(T)-integrated yield (dN/dy), and the ratio of the K*(892)(+/-) to K-S(0) yields are reported. These are consistent with previous K*(892)0 resonance results with a higher level of precision. Comparisons with phenomenological models such as PYTHIA6, PYTHIA8, EPOS-LHC, and DIPSY are also discussed. For the first time, a significant K*(892)(+/-)/K-S(0) suppression in pp collisions is observed at a 7.. level passing from low to high multiplicity events. The ratios of the p(T)-differential yields of K*(892)(+/-) and K-S(0) in high and low multiplicity events are also presented along with their double ratio. For p(T) less than or similar to 2 GeV/c this double ratio persists below unity by more than 3 sigma suggesting that the suppression affects mainly low p(T) resonances. The measured decreasing trend of the K*(892)(+/-)/K-S(0) ratio with increasing multiplicity, which in heavy-ion collisions is typically attributed to the rescattering of decay particles of the short-lived resonances, is reproduced by the EPOS-LHC model without the use of hadronic afterburners