Characterisation of plastic scintillator paddles and lightweight MWPCs for the MID subsystem of ALICE 3

The ALICE collaboration is proposing a completely new detector, ALICE 3, foroperation during the LHC Runs 5 and 6. One the ALICE 3 subsystems is the MuonIDentifier detector (MID), which has to be optimised to be efficient for thereconstruction of $J/\psi$ at rest (muons down to $p_{\rm T}\approx1.5$GeV/$c$) for $|\eta|<1.3$. Given the modest particle fluence expected in theMID of a few Hz/cm$^2$, technologies like plastic scintillator bars ($\approx1$length) equipped with wavelength-shifting fibers and silicon photomultiplierreadout, and lightweight Multi-Wire Proportional Chambers (MWPCs) are underinvestigation. To this end, different plastic scintillator paddles and MWPCswere studied at the CERN T10 test beam facility. This paper reports on theperformance of the scintillator prototypes tested at different beam energies(from 0.5 GeV/$c$ up to 6 GeV/$c$) and positions (horizontal, vertical, andangular scans). The MWPCs were tested at different energies (from 0.5 GeV/$c$to 10 GeV/$c$) and beam intensities, their efficiency and position resolutionswere verified beyond the particle rates expected with the MID in ALICE 3.