Diffraction and Low-x 2022

Effect of Sudakov factor in Golec-Biernat Wusthoff saturation model

25 Sept 2022, 10:05

20m

Corigliano Calabro, Italy

Recent theoretical results on QCD and saturation Recent theoretical results on QCD and saturation

Speaker

Tomoki Goda (IFJ PAN)

Description

We investigate improvements on models of dipole cross-section, one of which was originally proposed by Golec-Biernat and W\"usthoff (GBW), and the other is a DGLAP improved model proposed by Bartels, Golec-Biernar and Kowalski (BGK), which has improved small dipole behaviour.
Both models have been very successful in describing saturation phenomenon in small $x$ DIS.
In this study, we incorporate Sudakov factor which makes the dipole cross-section hard scale $Q^2$ (photon virtuality) dependent.
The parameters are fitted to HERA data and ${\chi }^2$ value are obtained for each model.
The GBW model, which showed strong deviation from the data with $Q^2$ above $\sim 50{\mathrm{GeV}}^2$, improves noticeably at large $Q^2$ due to the hard scale dependence. For the data $Q^2<100{\mathrm{GeV}}^2$, the ${\chi }^2$ value is reduced by $\sim 10\mathrm{\%}$. The ${\chi }^2$ value of the BGK model improves by $\sim 15\mathrm{\%}$, for the data $Q^2<650{\mathrm{GeV}}^2$.

Presentation materials

presentation-TGoda.pdf