https://doi.org/10.1140/epja/s10050-021-00517-5
Regular Article - Theoretical Physics
Physical limits in the color-dipole model bounds
Physics Department, Razi University, 67149, Kermanshah, Iran
a grboroun@gmail.com, boroun@razi.ac.ir
Received:
13
April
2021
Accepted:
8
June
2021
Published online:
5
July
2021
The ratio of the cross-sections for the transverse and longitudinal virtual photon polarizations, 
, at high photon–hadron energy scattering is studied. The relationship between the gluon distributions obtained using the color-dipole model and standard gluons obtained from the Dokshitzer–Gribov–Lipatov–Altarelli-Parisi (DGLAP) evolution and the Altarelli–Martinelli equations is investigated. It is shown that the color-dipole bounds are dependent on the gluon distribution behavior. This behavior is considered by expansion and Laplace-transform methods. Numerical calculations at leading order (LO) and next-to-leading order (NLO) approximations and a comparison with the color-dipole model (CDM) bounds indicate the range of validity of this method at small dipole sizes, 
.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
