Examination of $k_t$-factorization in a Yukawa theory

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Guiot, B., van Hameren, A.
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866929326977449984
author Guiot, B.
van Hameren, A.
author_facet Guiot, B.
van Hameren, A.
contents We discuss the upper limit, $k_{\text{max}}$, of the transverse-momentum integration performed in the $k_t$-factorization formula. Based on explicit calculations in the Yukawa theory and the study of seminal papers, we argue that $k_{\text{max}}$ is equal to the factorization scale $μ_F$ used to factorize the cross section into an off-shell hard coefficient and a universal factor. There is consequently a relation between $k_{\text{max}}$ and the definition of unintegrated parton densities (UPDFs). The use of an inconsistent relation leads potentially to the overestimation of the cross section, which has been observed, e.g., in D-meson production. One of our conclusions is that UPDFs related to collinear PDFs by an integration up to $μ\sim Q$, where $Q$ is the hard scale and $μ$ the scale in the collinear PDFs, imply that $k_{\text{max}}^2 \sim Q^2$. Integrating the transverse-momentum significantly above may result in the overestimation of the cross section. On the opposite, for UPDFs related to the collinear ones by an integration of the transverse momentum up to infinity, any $k_{\text{max}}^2 > Q^2$ is fine.
format Preprint
id arxiv_https___arxiv_org_abs_2401_06888
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Examination of $k_t$-factorization in a Yukawa theory
Guiot, B.
van Hameren, A.
High Energy Physics - Phenomenology
We discuss the upper limit, $k_{\text{max}}$, of the transverse-momentum integration performed in the $k_t$-factorization formula. Based on explicit calculations in the Yukawa theory and the study of seminal papers, we argue that $k_{\text{max}}$ is equal to the factorization scale $μ_F$ used to factorize the cross section into an off-shell hard coefficient and a universal factor. There is consequently a relation between $k_{\text{max}}$ and the definition of unintegrated parton densities (UPDFs). The use of an inconsistent relation leads potentially to the overestimation of the cross section, which has been observed, e.g., in D-meson production. One of our conclusions is that UPDFs related to collinear PDFs by an integration up to $μ\sim Q$, where $Q$ is the hard scale and $μ$ the scale in the collinear PDFs, imply that $k_{\text{max}}^2 \sim Q^2$. Integrating the transverse-momentum significantly above may result in the overestimation of the cross section. On the opposite, for UPDFs related to the collinear ones by an integration of the transverse momentum up to infinity, any $k_{\text{max}}^2 > Q^2$ is fine.
title Examination of $k_t$-factorization in a Yukawa theory
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2401.06888