Proton fragmentation functions considering finite-mass corrections

TL;DR

This paper introduces new proton fragmentation functions that incorporate finite-mass corrections, improving data description and enabling predictions for proton production in top quark decays.

Contribution

It provides the first comprehensive set of proton fragmentation functions including finite-mass effects, fitted to electron-positron data and applied to top quark decay predictions.

Findings

Finite-mass effects significantly improve fit quality.

Fragmentation functions are consistent with $e^+e^-$ data.

Predictions for proton production in top decays are provided.

Abstract

We present new sets of proton fragmentation functions describing the production of protons from the gluon and each of the quarks, obtained by a global fit to all relevant data sets extracted from the single-inclusive electron-positron annihilation. Our analysis is in good agreement with $e^+e^-$ annihilation data. We also impose the finite-mass effects of proton in our calculations, a topic with a very little attention paid to in the literatures. Proton mass effects turn out to be appreciable for the gluon and light quark fragmentation functions, so the inclusion of finite-mass effects tends to improve the overall description of the data by reducing the minimized $\chi^2$ values, significantly. As an application, we also apply the extracted fragmentation functions to make our predictions for the scaled-energy distribution of protons inclusively produced in top quark decays at next-to-leading order, relying on the universality and scaling violations of fragmentation functions.