The ALICE fixed-target programme layout using bent crystals at the CERN Large Hadron Collider.

Description du projet

Sonder le potentiel d’ALICE pour des expériences à cible fixe

Le Grand collisionneur de hadrons (LHC) est le plus puissant accélérateur de particules jamais construit, poussant les protons ou les ions à se déplacer à une vitesse proche de celle de la lumière. ALICE est un détecteur d’ions lourds situé sur l’anneau du LHC. Il est conçu pour étudier la physique de la matière en forte interaction à des densités d’énergie extrêmes, où se forme une phase de la matière appelée plasma quark-gluon. Le projet FIXEDTARGETLAND, financé par l’UE, étudiera le potentiel d’ALICE pour mener des expériences à cible fixe. La solide cible interne couplée à un cristal courbé pourrait permettre à ALICE de fonctionner dans un tel mode. Les paramètres de l’accélérateur et du cristal seront déterminés sur la base d’outils semi-analytiques et de simulations. Le mode à cible fixe permet d’étudier plus intensivement des processus rares, de nouvelles corrélations de spin, la physique diffractive et les phénomènes nucléaires.

Objectif

ALICE in the FixedTargetLand.

The LHC at CERN is the world largest and most powerful particle accelerator colliding beams of protons and lead ions. ALICE is one of detector experiments optimised for heavy-ions. A research potential of the CERN accelerator complex and infrastructure can be expanded by deflecting the LHC beam halo particles by means of bent crystals on a fixed-target placed inside the ALICE experiment. A fixed-target experiment at such a high energy offers many physics opportunities related to the the parton content of the nucleon and nucleus at high-x, the nucleon spin and the Quark-Gluon Plasma. Feasibility of beam halo deflection using crystal channeling has been experimentally demonstrated at CERN, for both proton and lead ion beams. There are two main objectives of the proposal. The first objective is to assess the feasibility and performance of the ALICE crystal-based fixed-target programme layout from the accelerator complex side, e.g. compatibility with the collimation, impact on vacuum, impedance, etc. The second objective is to calculate particles production within the target and response of the ALICE detector in order to evaluate the physics potential of the project.
Accelerator and crystal parameters will be determined based on semi-analytical tools followed up by complete multi-turn tracking simulations using the SixTrack and BDSIM codes. The detector response and physics reach will be evaluated in collaboration with the ALICE experts, mostly from the Warsaw University of Technology (WUT). The proposal assumes a transfer of applicant's knowledge and experience obtained at CERN related to particle accelerators, collimation and crystals to an interdisciplinary project. In return, WUT is a partner providing the necessary expertise on particle physics and the ALICE detector. Moreover, WUT opens a possibility of a personal growth through teaching students, knowledge exchange and building a network for establishing an own research group.