COEPP-MN-15-1
LU-TP-15-16
MCNET-15-09
arXiv:1505.01681
JHEP 1508 (2015) 003

by: Christiansen, Jesper R. (Lund U.) et al.

Abstract:
We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading N$_{C}$ are allowed to influence the formation of confining potentials (strings). The multiplet structure of SU(3) is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for “baryonic” configurations (e.g., two colours can combine coherently to form an anticolour). In e$^{+}$ e$^{−}$collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in pp collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive 1/N$_{C}^{2}$ suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important 〈p$_{⊥}$〉 (n$_{charged}$) distribution but also with measured rates (and ratios) of kaons and hyperons, in both ee and pp collisions. Nonetheless, the shape of their p$_{⊥}$ spectra remains challenging to explain.