String formation beyond leading colour

• Published in: The journal of high energy physics Vol. 2015; no. 8; pp. 1 - 52
• Main Authors: Christiansen, Jesper R., Skands, Peter Z.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2015; Springer Nature B.V
• Subjects: Classical and Quantum Gravitation; Collisions; Color; Colour; Confining; Elementary Particles; Formations; Fysik; High energy physics; Kaons; Monte Carlo Simulations; Natural Sciences; Naturvetenskap; Partons; Physical Sciences; Physics; Physics and Astronomy; QCD Phenomenology; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Strings; Subatomic Physics; Subatomär fysik; Monte Carlo Simulations; QCD Phenomenology
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP08(2015)003

A
bstract
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.