Topic 1: Gluon distributions at LHC and EIC
Description & objectives:
Gluons are the force carriers of the strong interaction, which is one of the four fundamental forces of Nature. The
microscopic theory of the strong interaction is the quantum theory of quarks and gluons, called Quantum Chromodynamics (QCD).
Gluons are confined inside protons and this makes the study of their properties difficult. Only in high energy
scattering processes those properties become apparent. The momentum distribution of gluons inside protons is quite well
known experimentally, but there are many other distributions that capture additional properties of the gluons inside protons,
such as the polarization states of the gluons, but also the spatial distribution of gluons and the correlations between the polarization
and the position and momentum. In this way one is dealing with many types of higher dimensional distributions, such
as gluon Transverse Momentum Distributions (TMDs), Generalized Parton Distributions (GPDs), Generalized TMDs (GTMDs),
Double distributions and diffractive distributions. There are ample opportunities to study such gluon distributions
in the proton-proton collision at the Large Hadron Collider (LHC) at CERN and in electron-proton collisions at the
Electron-Ion Collider (EIC) to be constructed at BNL (Long Island, NY). Most of these studies are complementary and
the combined information is key to getting a more complete picture of the gluonic properties of protons and nuclei.
With such distributions one can address questions about the gluonic/mass radius of the proton or the pressure distribution
of the proton.
One specific objective I have is to fully exploit the synergies between the experiments at LHC and EIC and to investigate
whether a common gluonic description of completely different classes of
processes (exclusive, diffractive, and semi-inclusive) can be obtained. Until very recently these processes were studied by separate
communities and topics of discussion at separate conferences, but now we start to uncover the aspects that they have in common and
relate results that were always thought to be unconnected.
Selected scientific highlights:
- Joint ECFA-NuPECC-ApPEC Activity Workshop "Synergies between the EIC and the LHC", DESY, Hamburg, December
14–15, 2023.
- C. Setyadi, "Studies of Generalized Transverse Momemtum Dependent gluon distributions",
PhD thesis 2023.
- Daniël Boer, Chalis Setyadi, "Probing gluon GTMDs through exclusive coherent diffractive processes",
European Physical Journal C 83 (2023) 890.
- Daniël Boer, Yoshikazu Hagiwara, Jian Zhou, Ya-jin Zhou, "Scale evolution of T-odd gluon TMDs at small x",
Physical Review D 105 (2022) 096017.
- Kick-off meeting of the Joint ECFA-NuPECC-ApPEC Activity "Synergies between the Electron-Ion Collider
and the Large Hadron Collider experiments", CERN, June 20–21, 2022.
- Joint ECFA-NuPECC-ApPEC Activity Expression of Interest "Synergies between the Electron-Ion Collider
and the Large Hadron Collider experiments", D. Boer, F. Sabatié, et al., 2021–2022.
- Daniël Boer, Chalis Setyadi, "GTMD model predictions for diffractive dijet production at EIC", Physical
Review D 104 (2021) 074006.
- D. Boer, P.J. Mulders, J. Zhou, Y.-J. Zhou, "Suppression of maximal linear gluon polarization in angular
asymmetries", JHEP 1710 (2017) 196.
- D. Boer, S. Cotogno, T. van Daal, P.J. Mulders, A. Signori and Y.J. Zhou, "Gluon and Wilson loop TMDs for hadrons of spin less than or equal to 1", JHEP 1610 (2016) 013.
- D. Boer, P.J. Mulders, C. Pisano and J. Zhou, "Asymmetries in heavy quark pair and dijet production at an EIC", JHEP 1608 (2016) 001.
- D. Boer, M.G. Echevarria, P. Mulders and J. Zhou, "Single spin asymmetries from a single Wilson loop", Physical Review Letters 116 (2016) 122001.
- D. Boer, C. Lorcé, C. Pisano and J. Zhou, "The gluon Sivers distribution: status and future prospects", Adv. High Energy Phys. 2015 (2015) 371396.
- D. Boer and C. Pisano, "Impact of gluon polarization on Higgs boson plus jet production at the LHC",' Physical Review D 91 (2015) 074024.
- D. Boer and W.J. den Dunnen, "TMD evolution and the Higgs transverse momentum distribution", Nuclear Physics B 886 (2014) 421.
- C. Pisano, D. Boer, S.J. Brodsky, M.G.A. Buffing and P.J. Mulders, "Linear polarization of gluons and photons in unpolarized collider experiments", JHEP 1310 (2013) 024.
- Wilco den Dunnen, "Polarization effects in proton-proton collisions within the Standard model and beyond", PhD thesis 2013.
- D. Boer and C. Pisano, "Polarized gluon studies with charmonium and bottomonium at LHCb and AFTER", Physical Review D 86 (2012) 094007.
- D. Boer, W.J. den Dunnen, C. Pisano, M. Schlegel and W. Vogelsang, "Linearly polarized gluons and the Higgs transverse momentum distribution”, Physical Review Letters 108 (2012) 032002.
- D. Boer, S.J. Brodsky, P.J. Mulders and C. Pisano, "Direct probes of linearly polarized gluons inside unpolarized hadrons", Physical Review Letters 106 (2011) 132001.
Funding:
Part of the research on this topic has been financially supported by the Indonesian Endowment Fund for Education LPDP and the Dutch funding agency FOM (now part of NWO).