Speaker: Prof. Dieter Roehrich (University ofBergen, Norway)
Time:  Dec.9, Tuesday, 10:30
Location:  Lecture Hall 9409

Abstract:

The parton structure of the nucleus at very low Bjorken-x, especially its gluon content, is largely unknow.  Measurements at small-x will not only provide experimental constrains for (nuclear) PDFs in a region of phasespace where experimental data is scarce, but will also enable the study of non-linear QCD effects such as gluon saturation. The scale at which saturation effects set in can be explored in the forward region of proton-proton and proton-nucleus collisions at the LHC. The ALICE Forward Calorimeter (FoCal) upgrade aims to investigate gluon PDFs down to Bjorken-x of ~10^-6 at a momentum transfer of Q ~ 4 GeV/c with direct photons. Positioned at very forward rapidities (3.4 < η < 5.8), FoCal will offer exceptional spatial resolution and ultra-fine granularity, making it uniquely capable of measuring direct photons, neutral mesons, and jets in a kinematic region sensitive to small-x gluons, as well as photo-production of vector mesons such as the J/psi in proton-Pb and Pb-Pb ultra-peripheral collisions.

Introduction: 

Dieter Roehrich, Professor for experimental nuclear physics at the University of Bergen in Norway. PhD from the Philipps-Universität Marburg, Germany, in 1986. Worked at the University of Frankfurt, BNL and CERN. Academician of the Norwegian Academy of Technological Sciences (NTVA). Research interests: ultra-relativistic nuclear collision, instrumentation, and medical physics. 

PPT or PDF file download:/FoCal_Wuhan_2025.pdf