PYTHIA hadronization process tuning in the GENIE neutrino interaction generator

Abstract

Next generation neutrino oscillation experiments utilize details of hadronic final states to improve the precision of neutrino interaction measurements. The hadronic system was often neglected or poorly modeled in the past, but they have significant effects on high precision neutrino oscillation and cross-section measurements. Among the physics of hadronic systems in neutrino interactions, the hadronization model controls multiplicities and kinematics of final state hadrons from the primary interaction vertex. For relatively high invariant mass events, many neutrino experiments rely on the PYTHIA program. Here, we show a possible improvement of this process in neutrino event generators, by utilizing expertise from the HERMES experiment. Finally, we estimate the impact on the systematics of hadronization models for neutrino mass hierarchy analysis using atmospheric neutrinos such as the PINGU experiment.

Detecting and studying high-energy collider neutrinos with FASER at the LHC

“…Hadronization is governed by Genie's "AKGY" model [96], which uses PYTHIA6 [66] for the invariant masses W ≥ 3 GeV that are most relevant for FASERν. The high-W model is tuned to BEBC data on measured neutrino-hydrogen particle multiplicities [97], although other authors have found better agree-ment with other datasets by retuning the model [98]. Final State Interactions, where particles produced at the interaction vertex can re-interact before leaving the nucleus, are modelled with Genie's INTRANUKE "hA" intranuclear cascade model [99], which is tuned to π -iron and π -nucleon scattering data, and is then extrapolated to other targets with A 2/3 scaling, where A is the atomic number.…”

Intrinsic limits on resolutions in muon- and electron-neutrino charged-current events in the KM3NeT/ORCA detector

“…ref. [29], and references contained therein). The impact of variation in PYTHIA parameters has been found to be small for inelasticity measurements [29].…”

“…[29], and references contained therein). The impact of variation in PYTHIA parameters has been found to be small for inelasticity measurements [29]. As discussed in section 5 however, inelasticity is also relatively insensitive to intrinsic fluctuations, and so is not a good indicator of model sensitivity.…”

First Look at PYTHIA8 Hadronization Program for Neutrino Interaction Generators

“…Fig. 3 shows the data-MC comparison of the averaged charged hadron multiplicities in ν µ − p andν µ − p interactions [15]. Here, the two curves represent predictions from default GENIE and GENIE with a PYTHIA6 tuned using one of the parameter set from the HERMES experiment [25].…”