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+${}^3P_0$ 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 $10.6\,\rm{GeV}$. 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.
Volume 477 -
7th International Workshop on “Transverse phenomena in hard processes and the transverse structure of the proton (Transversity2024) -
Main session
Monte Carlo results on the Collins asymmetries in $e^+e^-$ annihilation
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Published on:
December 04, 2024
Abstract
DOI: https://doi.org/10.22323/1.477.0007
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Copyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.