# Transverse parton momenta in single inclusive hadron production in ${e^ + }{e^ - }$ annihilation processes

## TL;DR

This study analyzes transverse momentum distributions in single inclusive hadron production from electron-positron annihilation, revealing TMD evolution features and favoring a power-law model over Gaussian for data description.

## Contribution

It demonstrates the applicability of TMD evolution in e+e- annihilation and compares different p_perp parameterizations using existing experimental data.

## Key findings

- Power-law model better fits the data than Gaussian.
- TMD evolution features are observable in e+e- processes.
- Non-perturbative effects are evident in the transverse momentum distributions.

## Abstract

We study the transverse momentum distributions of single inclusive hadron production in ${e^ + }{e^ - }$ annihilation processes. Although the only available experimental data are scarce and quite old, we find that the fundamental features of transverse momentum dependent (TMD) evolution, historically addressed in Drell-Yan processes and, more recently, in Semi-inclusive deep inelastic scattering processes, are visible in ${e^ + }{e^ - }$ annihilations as well. Interesting effects related to its non-perturbative regime can be observed. We test two different parameterizations for the $p_\perp$ dependence of the cross section: the usual Gaussian distribution and a power-law model. We find the latter to be more appropriate in describing this particular set of experimental data, over a relatively large range of $p_\perp$ values. We use this model to map some of the features of the data within the framework of TMD evolution, and discuss the caveats of this and other possible interpretations, related to the one-dimensional nature of the available experimental data.