Skip to main content

Mapping the 3-dimensional gluon structure of the proton

Periodic Reporting for period 1 - GlueCore (Mapping the 3-dimensional gluon structure of the proton)

Reporting period: 2018-09-01 to 2020-08-31

Gluons, together with quarks, are the fundamental constituents of the proton. They generate almost all its mass, carry about half of its momentum and contribute to its spin in a still unconstrained amount. Mapping their three-dimensional (3D) structure in the proton is crucial in our understanding of Quantum Chromodynamics and matter in general. The quark and gluon 3D content in momentum space is encoded in the so-called Transverse-Momentum-Dependent distribution/fragmentation functions (TMDs). While a huge progress had been made recently in the quark sector, the gluon sector was much less developed, due to the difficulty to cleanly probe gluons in high-energy processes. A very promising and also challenging way to access them is through quarkonium production (bound states of a quark-anti quark pair) in high-energy colliders. However, there was no solid framework which connected gluon TMDs to these processes.

The main goal of this project was to provide this new theoretical framework to properly access (un)polarized gluon TMDs through quarkonium production, also in view of the construction of new experimental facilities in Europe and the United States in the next decade, with the aim of collecting a wealth of data useful for gluon mapping.

This project brought new insights into our quest, as a society, of understanding the fundamental structure of matter. The same way as 3D imaging turned out to be revolutionary in many different ways for the man-kind, from medicine to location apps, the 3D mapping of nucleon structure will for sure have a tremendous impact in the future.
During the project a completely new theoretical formalism was developed to properly map 3D gluon structure of the nucleon in high-energy collisions, in particular using quarkonium production reaction. Also, several precision studies were performed, together with extensive phenomenological analyses. The results were published in different high-quality peer-reviewed journals, as well as presented in several international conferences.
The results of the project had a positive impact on the field, opening a new line of research, allowing a proper mapping of gluon 3D structure of nucleons. Current and future experimental facilities will benefit from the results of the project to interpret data with a solid theoretical ground.

On the other hand, the project had a great impact on the career of the researcher, allowing him to get a permanent position in a university back in his home country.