$\psi(2S)$ production in jets using NRQCD

Abstract

Based on recent data from LHCb, we study $\psi(2S)$ production in jets using non-relativistic QCD (NRQCD) in conjunction with the Fragmenting Jet Function (FJF) and Gluon Fragmentation Improved Pythia (GFIP) formalisms. Similar to previous studies of $J/\psi$ production in jets, our results show that these formalisms offer a much better description of data than the default Pythia+NRQCD prediction. We compare and contrast the predictions from the FJF formalism and the GFIP approach. In addition, our results show that the distribution of $\psi(2S)$ in jets is an excellent discriminator to test different predictions for the $\psi(2S)$ LDMEs from various extractions. We find a large disparity between the predictions from three different collaborations, showing that a more precise extraction of the $\psi(2S)$ LDMEs may be necessary.