# Heavy-quark production with $k_t$-factorization: The importance of the sea-quark distribution

## TL;DR

This paper examines the limitations of $k_t$-factorization in heavy-quark production, emphasizing the significant role of sea-quark distributions and the necessity of including processes beyond gluon-gluon interactions for accurate predictions.

## Contribution

It highlights the importance of sea-quark contributions in $k_t$-factorization calculations and clarifies the dominant processes in different flavor schemes for heavy-quark production.

## Key findings

- $gg$-only calculations often underestimate data without large $K$ factors.
- In the variable-flavor-number scheme, $Qg
ightarrow Qg$ dominates heavy-quark production.
- Sea-quark distributions are crucial for accurate $k_t$-factorization predictions.

## Abstract

We discuss the fact that $k_t$-factorization calculations for heavy-quark production include only the $gg\rightarrow Q\bar{Q}$ contribution. The cases of fixed-flavor-number scheme and variable-flavor-number scheme calculations are analyzed separately. For the latter, we show that, similarly to the collinear factorization, the main contribution is given by the $Qg\rightarrow Qg$ process. In this scheme, calculations including only the $gg$ contribution should show a large discrepancy with the data. We show that, if they do not, it is because they include (effectively) a large $K$ factor.