Probing Gluons at the Spin Physics Detector

TL;DR

The Spin Physics Detector at NICA aims to explore gluon distributions within nucleons through polarized collisions, providing unique insights into spin structure and tensor polarization, complementing existing high-energy experiments.

Contribution

This paper introduces the SPD experiment at NICA, highlighting its capabilities to probe gluon distributions and tensor polarization in nucleons, which is novel compared to previous experiments.

Findings

Potential to measure gluon spin asymmetries

Probing tensor polarized gluon distributions

Complementary data to RHIC, EIC, and LHC experiments

Abstract

The Spin Physics Detector (SPD) at the Nuclotron based Ion Collider fAcility (NICA) is a multi-purpose experiment designed to study nucleon spin structure in the three dimensions. With capabilities to collide polarized protons and deuterons with center of mass energy up to 27 GeV and luminosity up to $10^{32} \rm cm^{-2} \ s^{-1}$ for protons (an order of magnitude less for deuterons), the experiment will allow measurements of cross-sections and spin asymmetries of hadronic processes sensitive to the unpolarized and various polarized (helicity, Sivers, Boer-Mulders) gluon distributions inside the nucleons. Results from the SPD will be complementary to the present high energy spin experiments at the RHIC facility or future experiments like the EIC (at BNL) and AFTER (at LHC). SPD will provide data in moderate and large Bjorken-x for much improved global analyses of spin structures of the basic building blocks of Nature. With polarized deuteron collisions, SPD will be the unique laboratory for probing tensor polarized gluon distributions. In addition, there are also possibilities of colliding other light nuclei like Carbon at reduced collision energy and luminosity at the first stage of the experiment.