A Framework for Hadronic Rescattering in pp Collisions

Abstract

In this article, a framework for hadronic rescattering in the general-purpose Pythia event generator is introduced. The starting point is the recently presented space-time picture of the hadronization process. It is now extended with a tracing of the subsequent motion of the primary hadrons, including both subsequent scattering processes among them and decays of them. The major new component is cross-section parameterizations for a range of possible hadron-hadron combinations, applicable from threshold energies upwards. The production dynamics in these collisions has also been extended to cope with different kinds of low-energy processes. The properties of the model are studied, and some first comparisons with LHC pp data are presented. Whereas it turns out that approximately half of all final particles participated in rescatterings, the net effects in pp events are still rather limited, and only striking in a few distributions. The new code opens up for several future studies, however, such as effects in pA and AA collisions.

Hadron production in elementary nucleon-nucleon reactions from low to ultra-relativistic energies

“…16 that the FSI effect is relatively small, on the level of 5% in average. This PHSD result is consistent with a recent finding by Sjöstrand and Utheim [25] who incorporated the framework for accounting of the FSI in PYTHIA in terms of hadronic rescattering.…”

“…due to a very low density of produced hadrons; the FSI effect grows with increasing collision energies, however, even at the LHC energies it gives less then 5% increase of the charged hadron multiplicities and only small changes in the transverse momentum spectra. This PHSD finding is in line with the recent results by the Lund group [25] where the hadronic FSI effect has been incorporated in PYTHIA within a framework of the space-time picture of p + p collisions. We also showed the influence on p T spectra of the possible small QGP droplet formation in p + p collisions at LHC energies and found only a very small effect here.…”

“…We note here that recently a framework for hadronic rescattering in p+p collisions has been proposed for PYTHIA in Ref. [25]. The inclusion of final state interactions can slightly change the final multiplicity of hadrons as compared to the production point by string decay, as well as their momentum distribution due to elastic scattering as will be discussed in Section 4.…”

Production of $f_2(1270)$ meson in $pp$ collisions at the LHC via gluon-gluon fusion in the $k_t$-factorization approach

“…The effect of hadronic rescattering in high-energy pp collisions was discussed very recently in [31] and the application is being developed and will be implemented to PYTHIA event generator.…”