Open questions in fragmentation and hadronisation for precision collider physics

Identify and address the key challenges in fragmentation and hadronisation modelling required to reach the precision goals of future e+e− colliders, including: (i) implementing recent perturbative fragmentation-function advances within exclusive Monte Carlo generators; (ii) quantifying the impact of shower, fragmentation, and hadronisation uncertainties on flagship Higgs, top, and electroweak measurements; (iii) defining and measuring target observables to constrain hadronisation models; (iv) determining detector capabilities needed to achieve the required sensitivity; and (v) establishing access to and translation of LEP archived data into modern frameworks for validating new calculations and simulation tools.

Background

Nonperturbative hadronisation effects and their interplay with parton showers are expected to be limiting factors for precision measurements at future Higgs/electroweak/top factories.

Recent developments in perturbative fragmentation functions, colour reconnection, and hadronisation models need to be coherently integrated and validated using dedicated observables and high-quality data.

Clarifying detector performance requirements and leveraging LEP legacy datasets will be instrumental in constraining models and reducing systematic uncertainties to match the precision of upcoming measurements.