Monte Carlo results on the Collins asymmetries in e⁺e^- annihilation

2024/10/15 by Kerbizi, A., Lönnblad, L., Martin, A.
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2410.11489

Abstract

The quark spin effects have been introduced in the Pythia 8 Monte Carlo event generator for the simulation of e⁺e^- annihilation by interfacing the generator with the StringSpinner package. The package allows to simulate quark spin effects in the string fragmentation routine of Pythia by using the string+³P₀ model, recently applied to the fragmentation of a string stretched between a quark-antiquark pair with correlated spin states. StringSpinner is used to carry out simulations of e⁺e^- annihilation at the center of mass energy of 10.6 \rmGeV. The Collins asymmetries are extracted from the simulated data for back-to-back pion pairs using both the thrust axis method and the hadronic plane method. The results are compared with the data from the BELLE and BABAR experiments, finding a satisfactory agreement.

Related

• Quark spin effects in e⁺e^- annihilation: a Monte Carlo event generator study
• Simulation of e⁺e^- annihilation with quark spin effects
• Modeling spin effects in electron-positron annihilation to hadrons
• String fragmentation of a quark pair with entangled spin states: application to e⁺e^- annihilation
• Adding quark spin effects to PYTHIA string fragmentation