"Analysis of high muon multiplicity cosmic events with the ALICE experiment"

Dr. Mario Rodríguez Cahuantzi
Departamento de Física, CINVESTAV-IPN


ALICE is one of the four main experiments of the LHC at CERN. Located 40 m underground with 30 m of overburden rock it can also operate to detect atmospheric muons produced by cosmic ray interactions in the atmosphere. The analysis of the data collected with cosmic triggers from 2010 until 2013, corresponding to around 25 days of live time, will be presented. Exploiting the specific capability of the Time Projection Chamber (TPC) in tracking an high number of charged particles, a special emphasis will be addressed in the study of muon bundles, with a particular attention on high muon density events. In particular the muon multiplicity distribution, that gives information on the primary cosmic ray composition in the energy range beyond the knee, has shown some unexpected events of very high multiplicity. The search and the study of these events, already detected in previous experiments as ALEPH and DELPHI at LEP, will be discussed in detail. An explanation of these events detected by ALICE, in terms of standard cosmic ray composition with the use of the last hadronic interaction models, will be discussed.