Proposal from the NA61/SHINE Collaboration for update of European Strategy for Particle Physics

TL;DR

The NA61/SHINE Collaboration proposes an extensive program of hadron production measurements post-CERN Long Shutdown 3, aiming to address key questions in heavy-ion, cosmic-ray, and neutrino physics through detector and beam upgrades.

Contribution

This proposal outlines a comprehensive plan for new measurements of hadron production to advance understanding in multiple physics domains, with planned upgrades and data collection from 2029 to 2032.

Findings

Insights into high-energy nuclear collisions and isospin symmetry violation.

Data on charm-anticharm correlations and production locality.

Improved cross sections for cosmic-ray and neutrino physics.

Abstract

Building on the current program's success and driven by new physics challenges, the NA61/SHINE Collaboration proposes to continue measuring hadron production properties in reactions induced by hadron and ion beams after CERN Long Shutdown 3. These measurements are of significant interest to the heavy-ion, cosmic-ray, and neutrino physics communities and will focus on: - Investigating hadron production in the light-ion systems to explore the diagram of high-energy nuclear collisions, and to obtain new insight into the unexpected violation of isospin (flavor) symmetry recently observed by the experiment; - Measuring charm-anticharm correlations to gain unique insights into the production locality of charm and anticharm quark pairs; - Examining strangeness and multi-strangeness production to improve our understanding of the early Universe's evolution and neutron star formation; - Measuring cross sections relevant for cosmic-ray measurements, significantly boosting searches for new physics in our Galaxy; - Conducting hadron production measurements with proton, pion, and kaon beams for neutrino physics, enhancing the precision of hadron production data needed for initial neutrino flux predictions in neutrino oscillation experiments; - Measuring hadron production processes relevant for understanding the flux of atmospheric neutrinos, as well as neutrinos and muons from spallation sources. To achieve these objectives, a detector upgrade and a beam upgrade are required, with data-taking planned for the period 2029-2032 and beyond.