NA61SHINE

NA61/SHINE, or the SPS Heavy Ion and Neutrino Experiment, is a fixed-target experimental program at CERN's Super Proton Synchrotron. It studies hadron production in hadron–nucleus and nucleus–nucleus collisions over a broad energy range. The project traces its heritage to NA49 and is conducted by an international collaboration.

The primary goals are to measure differential cross sections, multiplicities, and spectra of produced hadrons to improve models of strong interactions. A major emphasis is providing precise hadron production data needed for predicting neutrino fluxes in long‑baseline experiments such as T2K, and for tuning cosmic ray air shower simulations.

NA61/SHINE employs a large-acceptance tracking system based on time projection chambers around a fixed magnet, complemented by time‑of‑flight detectors and calorimetry. These detectors enable particle identification by dE/dx and velocity, allowing measurements of pions, kaons, protons, and other hadrons across rapidities and transverse momenta relevant to the physics program.

The experiment uses the SPS fixed-target beamline with various thin targets and a range of beam species, including protons and heavy ions, at multiple momenta. Data sets cover proton–nucleus, hadron–nucleus, and nucleus–nucleus collisions to map hadron production across energies and system sizes.

NA61/SHINE has produced widely used cross sections and spectra that underpin neutrino beam predictions and cosmic ray physics. It continues to collect and publish results, contributing to the calibration of interaction models and informing both accelerator-based and astroparticle experiments.