Study of hadron interactions in a lead-emulsion target

Abstract

Topological and kinematical characteristics of hadron interactions have been studied using a lead-emulsion target exposed to 2, 4 and 10 GeV/c hadron beams. A total length of 60 m ${\pi }^{-}$ tracks was followed using a high speed automated emulsion scanning system. A total of 318 hadron interaction vertices and their secondary charged particle tracks were reconstructed. Measurement results of interaction lengths, charged particle multiplicity, emission angles and momenta of secondary charged particles are compared with a Monte Carlo simulation and appear to be consistent. Nuclear fragments emitted from interaction vertices were also detected by a newly developed emulsion scanning system with wide-angle acceptance. Their emission angle distributions are in good agreement with the simulated distributions. Probabilities of an event being associated with at least one fragment track are found to be greater than 50% for beam momentum $P>4$ GeV/c and are well reproduced by the simulation. These experimental results validate estimation of the background due to hadron interactions in the sample of $\tau$ decay candidates in the OPERA ${\nu }_{\mu }\to {\nu }_{\tau }$ oscillation experiment.

14 pages, 11 figures

References in corpus (1)

• Observation of a first ${\nu }_{\tau }$ candidate in the OPERA experiment in the CNGS beam

Cited by in corpus (6)

• Discovery of tau neutrino appearance in the CNGS neutrino beam with the OPERA experiment
• Final results of the OPERA experiment on ${\nu }_{\tau }$ appearance in the CNGS beam
• Tau Neutrinos in the Next Decade: from GeV to EeV
• Automatic track recognition for large-angle minimum ionizing particles in nuclear emulsions
• Wide angle acceptance and high-speed track recognition in nuclear emulsion
• First observation of a tau neutrino charged current interaction with charm production in the Opera experiment