[Primexd] abstract for Nucleus2023

[vtarasov at jlab.org]

 Dear PrimEx-Eta members,

I am planning to present an updated report on the Nucleus-23 conference
this fall.
Below is the preliminary abstract of my talk. Please send your comments
and corrections asap.

Thank you and all the best,
 Victor.


Status report of the PrimEx-D experiment at Jefferson Lab on precision
measurements of the η→γγ decay width.


Precision measurement of the η→γγ decay width is essential for determining
the fundamental parameters of QCD, such as the mass ratio of light quarks,
the mixing angle η-η΄, and studying the chiral symmetry breaking.
Accurate, at the level of 3%, measurement of the η→γγ decay width will
make it possible to proportionally reduce the uncertainties in the width
of the remaining eta-meson decay modes, as well as resolve the existing
discrepancy in the results between the collider and Primakoff experiments.

In 2022, the final part of the experimental data-taking has been
successfully finished. In my talk, I will update on the current status of
the experimental data analysis.