A next-generation LHC heavy-ion experiment

TL;DR

This paper proposes a next-generation, ultra-lightweight, multi-purpose detector for the LHC designed to significantly enhance heavy-ion collision studies with improved tracking, particle identification, and high-luminosity capabilities.

Contribution

It introduces a novel detector design using ultra-thin silicon sensors with unprecedented low material budget for advanced heavy-ion physics at the LHC.

Findings

Design achieves 0.05% X$_0$ material budget per layer

Enables particle identification with 20 ps time-of-flight resolution

Supports collision studies at 20-50 times higher luminosity

Abstract

The present document discusses plans for a compact, next-generation multi-purpose detector at the LHC as a follow-up to the present ALICE experiment. The aim is to build a nearly massless barrel detector consisting of truly cylindrical layers based on curved wafer-scale ultra-thin silicon sensors with MAPS technology, featuring an unprecedented low material budget of 0.05% X$_0$ per layer, with the innermost layers possibly positioned inside the beam pipe. In addition to superior tracking and vertexing capabilities over a wide momentum range down to a few tens of MeV/$c$, the detector will provide particle identification via time-of-flight determination with about 20~ps resolution. In addition, electron and photon identification will be performed in a separate shower detector. The proposed detector is conceived for studies of pp, pA and AA collisions at luminosities a factor of 20 to 50 times higher than possible with the upgraded ALICE detector, enabling a rich physics program ranging from measurements with electromagnetic probes at ultra-low transverse momenta to precision physics in the charm and beauty sector.