SciPost logo

SciPost Submission Page

JAM small-$x$ helicity phenomenology

by Daniel Adamiak

Submission summary

Authors (as registered SciPost users): Daniel Adamiak
Submission information
Preprint Link:  (pdf)
Date submitted: 2021-08-10 14:06
Submitted by: Adamiak, Daniel
Submitted to: SciPost Physics Proceedings
Proceedings issue: 28th Annual Workshop on Deep-Inelastic Scattering (DIS) and Related Subjects (DIS2021)
Ontological classification
Academic field: Physics
  • Nuclear Physics - Theory
Approaches: Theoretical, Phenomenological


We present the first-ever description the world data on the $g_1^{p,n}$ structure function at small Bjorken $x$ using evolution equations in $x$ derived from first principles QCD. This is a Monte-Carlo analysis within the JAM global framework that allows us to fit all existing polarized DIS data below $x<0.1$ as well as predict future measurements of small $x$ $g_1^{p,n}$ at the EIC. This is a necessary step in determining the quark helicity PDFs and, ultimately, the quark contribution to the proton spin.

Current status:
Awaiting resubmission

Reports on this Submission

Anonymous Report 1 on 2022-2-19 (Invited Report)


The proceeding presents a Monte Carlo-based analysis of the world data on polarized lepton-nucleon DIS at small Bjorken-$x$ within the polarized quark dipole formalism. To our knowledge, this is the first successful description of the double-spin asymmetries in polarized DIS at $x <$ 0.1 using the KPS small-$x$ evolution equations.
The proceeding is nicely-written and the results presented here are worthy of publication.

Minor comments:
$\bullet$ on page 4, $2^{nd}$ paragraph: at teh EIC. $\rightarrow$ at the EIC.
$\bullet$ on page 5, $1^{st}$ paragraph (just before the Conclusion section): $\Delta \Sigma$ are given in 4. $\rightarrow$ $\Delta \Sigma$ are given in Fig. 4.
$\bullet$ on page 5, in the Conclusion section, $2^{nd}$ paragraph: JAM smsall-x framework $\rightarrow$ JAM small-x framework

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Login to report or comment