Colliding and Fixed Target Mode in a Single Experiment -- A Novel Approach to Study the Matter under New Extreme Conditions

TL;DR

This paper introduces a new experimental approach using fixed target collisions at high energies to create and study QCD matter under extreme conditions, surpassing those found in the early universe and astrophysical phenomena.

Contribution

It proposes a novel fixed target collision method at colliders to achieve unprecedented baryonic charge densities in nuclear matter studies.

Findings

Triple nuclear collisions can reach baryonic charge densities three times higher than standard collisions.

Model simulations estimate effective reaction rates and energy deposition for proposed experimental setups.

The approach opens new avenues for exploring QCD matter under extreme conditions.

Abstract

Here, we propose a novel approach to experimentally and theoretically study the properties of QCD matter under new extreme conditions, namely having an initial temperature over 300~MeV and baryonic charge density over three times the values of the normal nuclear density. According to contemporary theoretical knowledge, such conditions were not accessible during the early Universe evolution and are not accessible now in the known astrophysical phenomena. To achieve these new extreme conditions, we proposed performing high-luminosity experiments at LHC or other colliders by means of scattering the two colliding beams at the nuclei of a solid target that is fixed at their interaction region. Under plausible assumptions, we estimate the reaction rate for the p+C+p and Pb+Pb+Pb reactions and discuss the energy deposition into the target and possible types of fixed targets for such reactions. To simulate the triple nuclear collisions, we employed the well-known UrQMD 3.4 model for the beam center-of-mass collision energies 2.76 TeV. As a result of our modeling, we found that, in the most central and simultaneous triple nuclear collisions, the initial baryonic charge density is approximately three times higher than the one achieved in the ordinary binary nuclear collisions at this energy.