Exploration of the physics potential of MARTA Engineering array
IDPASC Portugal - PHD Programme 2019
2019 / 2020
Experimental Particle Physics
Instituto Superior Técnico
Laboratório de Instrumentação e Física Experimental de Partículas ; Thesis to be done partly in Instituto Superior Técnico partly in Universidade do Minho
Nature and arrival direction of cosmic rays at the highest energies can only be inferred indirectly through the analysis of the air shower induced by their interaction with the atmosphere. The understanding of the shower development relies on our knowledge about the hadronic interactions that can occur at energies well above those reachable at accelerators on Earth. Muons, being long-lived particles, carry important information about these hadronic interactions that rule the shower development. Therefore, their detection at the ground is an essential tool to understand the physics of extensive air showers and particle interactions at extreme energies. However, the measurement of the highest energy extensive air-showers and in particular of the produced muons poses several challenges as it has to be performed in an outdoor environment, using detectors covering a vast area. Engaging this challenge the LIP group is leading the MARTA project, which proposes an innovative concept for the muon detection in air-shower experiments. MARTA (Muon Array of RPCs for Tagging Air showers) consists basically of robust RPCs (Resistive Plate Chambers) deployed under a Water Cherenkov Tank, which is sensitive to all kind of charged particles and is also used as an absorber of the shower electrons and gammas. This array will measure the muons on an event-by-event basis and will collect shower events produced mainly at a center-of-mass energy compatible to those reached currently at the Large Hadron Collider, LHC. Several full-scale MARTA prototypes are already installed and taking data in the Pierre Auger Observatory - currently the biggest cosmic ray observatory in the world - situated in Argentina. A MARTA Engineering Array (EA), consisting of seven MARTA stations, is planned to start to be deployed in Auger during 2019. The successful operation of the MARTA EA will be of the utmost importance for the proof-of-concept and a pathfinder for future experiments. The selected candidate will be involved in the activities of the LIP/Auger group, in particular: Participation on the commissioning of the MARTA Engineering Array; Validation of the detector concept and performance; Development of data analysis tools to reconstruct showers; Extract information from the showers using the MARTA EA and combine it with LHC to further constrain hadronic interaction properties.