Investigation of the Energy Loss of Muon Bundles in the Cherenkov Water Calorimeter
- PDF / 646,686 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 44 Downloads / 196 Views
ELEMENTARY PARTICLES AND FIELDS Experiment
Investigation of the Energy Loss of Muon Bundles in the Cherenkov Water Calorimeter E. A. Yurina1)* , N. S. Barbashina1), A. G. Bogdanov1) , S. S. Khokhlov1), V. V. Kindin1) , R. P. Kokoulin1), K. G. Kompaniets1) , G. Mannocchi2), A. A. Petrukhin1) , V. V. Shutenko1) , G. Trinchero2) , and I. I. Yashin1) Received July 12, 2019; revised July 12, 2019; accepted July 12, 2019
Abstract—Investigations of the energy loss of muon bundles are being conducted at the Experimental complex NEVOD. Such investigations are directed to detailed study of “muon puzzle” (the excess of multimuon events observed in several cosmic ray experiments at ultra-high energies). Results of measurements of the muon bundle energy deposit during a long period of observations in primary cosmic ray energy range 10–1000 PeV have been obtained and have been compared with simulations performed on the basis of the CORSIKA code. DOI: 10.1134/S1063778819660505
1. INTRODUCTION Excess of events with a large muon multiplicity in comparison with the simulation was found at the ALEPH [1] and DELPHI [2] detectors of the LEP accelerator at CERN. Analysis of DECOR data [3– 5] for muon bundles with high multiplicity at large zenith angles showed that the measured intensity of events cannot be explained in the framework of the existing models of hadron interaction, even under the assumption of a heavy mass composition (iron nuclei) at primary energies around 1018 eV. Measurements at the Pierre Auger Observatory [6, 7] also confirmed an excessive number of muons in inclined extensive air showers (EAS) in comparison with calculations in the energy range about 1019 eV. A recent analysis of the archival data of the EAS-MSU setup [8] for muons with energies 10 GeV in near-vertical showers did not reveal an excess of observed muons. But this conclusion was based on the study of EAS with energies >1017 eV. Also, the muon excess was not found at the ALICE detector [9] in CERN in which the experiment was conducted to study muon bundles at primary particle energies >1016 eV. In the DECOR data for the energy of 1017 eV the excess also was not found [4, 5]. The combination of these results indicates that the muon excess appears at least at ultrahigh energies of primary particles and increases with their energy. 1)
National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, 115409 Russia. 2) Osservatorio Astrofisico di Torino–INAF, Torino, Italy. * E-mail: [email protected]
To solve the muon excess problem (so-called “muon puzzle”) it is necessary to study the energy characteristics of muon bundles [10]. A possible approach is to measure the energy deposit of muon bundles in the detector material. Mean energy losses of muons almost linearly depend on their energy, and if an excessive flux of high-energy muons appears it would change the dependence of the average energy deposit of muon bundles on the energy of the primary particles. The energy characteristics of muon bundles have been investigated at the
Data Loading...
