Pythia 8.3 tuning based on Belle fragmentation related measurements

Sumitted to PubDB: 2026-01-07

Category: Report, Visibility: Public

Authors	Ralf Seidl
Date	2026-01-07
Belle II Number	BELLE2-REPORT-2026-001
Abstract	Belle has measured a large number of fragmentation-related results that have been already successfully used in global fits of fragmentation functions. These fragmentation functions are important input for studying the nucleon structure in semi-inclusive Deeply inelastic lepton nucleon scattering and hadron collisions. Apart from the additional flavor-sensitivity, also spin and transverse momentum of partons in the nucleon can accessed this way. Additionally, these fragmentation-related results should be extremely sensitive to the fragmentation parameters in Monte Carlo event generators. This note concentrates on the tuning efforts of pythia 8.3 using these measurements.