Two-loop anomalous dimensions for small-$R$ jet versus hadronic fragmentation functions

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: van Beekveld, Melissa, Dasgupta, Mrinal, El-Menoufi, Basem Kamal, Helliwell, Jack, Karlberg, Alexander, Monni, Pier Francesco
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914968415240192
author van Beekveld, Melissa
Dasgupta, Mrinal
El-Menoufi, Basem Kamal
Helliwell, Jack
Karlberg, Alexander
Monni, Pier Francesco
author_facet van Beekveld, Melissa
Dasgupta, Mrinal
El-Menoufi, Basem Kamal
Helliwell, Jack
Karlberg, Alexander
Monni, Pier Francesco
contents We study the collinear fragmentation of highly energetic jets defined with a small jet radius. In particular, we investigate how the corresponding fragmentation functions differ from their hadronic counterpart defined in the common $\overline{\rm MS}$ scheme. We find that the anomalous dimensions governing the perturbative evolution of the two fragmentation functions differ starting at the two loop order. We compute for the first time the new anomalous dimensions at two loops and confirm our predictions by comparing the inclusive small-$R$ jet spectrum against a fixed order perturbative calculation at ${\cal O}(α_s^2)$. To investigate the dependence of the anomalous dimension on the kinematic cutoff variable, we study the fragmentation functions of Cambridge jets defined with a transverse momentum cutoff as opposed to an angular cutoff $R$. We further study the evolution of the small-$R$ fragmentation function with an alternative cutoff scale, proportional to $z R$, representing the maximum possible transverse momentum of emissions within a jet. In these cases we find that the two-loop anomalous dimensions coincide with the $\overline{\rm MS}$ DGLAP ones, highlighting a correspondence between the $\overline{\rm MS}$ scheme and a transverse-momentum cutoff.
format Preprint
id arxiv_https___arxiv_org_abs_2402_05170
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Two-loop anomalous dimensions for small-$R$ jet versus hadronic fragmentation functions
van Beekveld, Melissa
Dasgupta, Mrinal
El-Menoufi, Basem Kamal
Helliwell, Jack
Karlberg, Alexander
Monni, Pier Francesco
High Energy Physics - Phenomenology
We study the collinear fragmentation of highly energetic jets defined with a small jet radius. In particular, we investigate how the corresponding fragmentation functions differ from their hadronic counterpart defined in the common $\overline{\rm MS}$ scheme. We find that the anomalous dimensions governing the perturbative evolution of the two fragmentation functions differ starting at the two loop order. We compute for the first time the new anomalous dimensions at two loops and confirm our predictions by comparing the inclusive small-$R$ jet spectrum against a fixed order perturbative calculation at ${\cal O}(α_s^2)$. To investigate the dependence of the anomalous dimension on the kinematic cutoff variable, we study the fragmentation functions of Cambridge jets defined with a transverse momentum cutoff as opposed to an angular cutoff $R$. We further study the evolution of the small-$R$ fragmentation function with an alternative cutoff scale, proportional to $z R$, representing the maximum possible transverse momentum of emissions within a jet. In these cases we find that the two-loop anomalous dimensions coincide with the $\overline{\rm MS}$ DGLAP ones, highlighting a correspondence between the $\overline{\rm MS}$ scheme and a transverse-momentum cutoff.
title Two-loop anomalous dimensions for small-$R$ jet versus hadronic fragmentation functions
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2402.05170